core: add creation of user variables in evaluated expressions with ${define:name,value}

31 files changed, 1701 insertions, 1355 deletions

diff --git a/ChangeLog.adoc b/ChangeLog.adoc
index 758a735ec..a57de7dc5 100644
--- a/ChangeLog.adoc
+++ b/ChangeLog.adoc
@@ -15,6 +15,13 @@ https://weechat.org/files/releasenotes/ReleaseNotes-devel.html[release notes]
 (file _ReleaseNotes.adoc_ in sources).
 
 
+[[v3.4]]
+== Version 3.4 (under dev)
+
+New features::
+
+  * api: add user variables in evaluation of expressions with "define:name,value"
+
 [[v3.3]]
 == Version 3.3 (2021-09-19)
 
diff --git a/doc/de/includes/autogen_user_commands.de.adoc b/doc/de/includes/autogen_user_commands.de.adoc
index 2f7cefe70..6e8dc132b 100644
--- a/doc/de/includes/autogen_user_commands.de.adoc
+++ b/doc/de/includes/autogen_user_commands.de.adoc
@@ -1337,123 +1337,126 @@ infolists: zeigt Information über die Infolists an
 /eval  [-n|-s] [-d] <expression>
        [-n] [-d [-d]] -c <expression1> <operator> <expression2>
 
-        -n: gibt das Ergebnis aus, ohne dass dieses in den Buffer gesendet wird (debug Modus)
-        -s: teilt Ausdrücke, bevor sie evaluiert werden (mehrere Befehle können durch Semikolon getrennt werden)
-        -d: eine Debug-Ausgabe nach Auswertung anzeigen (Nutzung von zwei -d: ausführliche Debug-Ausgabe)
-        -c: Auswertung als Bedingung: nutzt Operatoren und runde Klammern, Rückgabewert als Boolean-Wert ("0" oder "1")
-expression: Ausdruck welcher verarbeitet werden soll. Variablen im Format ${variable} werden ersetzt (siehe unten); mehrere Befehle werden durch ein Semikolon voneinander getrennt
-  operator: ein logischer oder vergleichender Operand:
-            - logische Operanden:
-                &&  boolean "und"
-                ||  boolean "oder"
-            - vergleichende Operanden:
-                ==  gleich
-                !=  ungleich
-                <=  kleiner oder gleich
-                <   kleiner
-                >=  größer oder gleich
-                >   größer
-                =~  stimmt mit regulärem POSIX Ausdruck überein
-                !~  stimmt NICHT mit regulärem POSIX Ausdruck überein
-                ==*  stimmt mit Maske überein (Platzhalter "*" ist erlaubt)
-                !!*  stimmt mit Maske NICHT überein (Platzhalter "*" ist erlaubt)
-                =*   stimmt mit Maske überein, Groß- und Kleinschreibung wird nicht beachtet (Platzhalter "*" ist erlaubt)
-                !*   stimmt mit Maske NICHT überein, Groß- und Kleinschreibung wird nicht beachtet (Platzhalter "*" ist erlaubt)
-                ==-  ist enthalten, Groß- und Kleinschreibung wird beachtet
-                !!-  ist NICHT enthalten, Groß- und Kleinschreibung wird beachtet
-                =-   ist enthalten, Groß- und Kleinschreibung wird nicht beachtet
-                !-   ist NICHT enthalten, Groß- und Kleinschreibung wird nicht beachtet
-
-Ein Ausdruck gilt als "wahr" sofern das Ergebnis weder NULL, nicht leer und von "0" abweichend ist.
-Für einen Vergleich werden Fließkommazahlen genutzt, insofern es sich bei beiden Ausdrücken um gültige Zahlen handelt, folgende Formate werden unterstützt:
-  - Integer (Beispiele: 5, -7)
-  - Fließkommazahl (Beispiele: 5.2, -7.5, 2.83e-2)
-  - hexadezimale Zahl (Beispiele: 0xA3, -0xA3)
-Um einen Vergleich zwischen zwei Zeichenketten zu erzwingen, müssen die Ausdrücke in Anführungszeichen gesetzt werden, zum Beispiel:
+        -n: display result without sending it to buffer (debug mode)
+        -s: split expression before evaluating it (many commands can be separated by semicolons)
+        -d: display debug output after evaluation (with two -d: more verbose debug)
+        -c: evaluate as condition: use operators and parentheses, return a boolean value ("0" or "1")
+expression: expression to evaluate, variables with format ${variable} are replaced (see below); many commands can be separated by semicolons
+  operator: a logical or comparison operator:
+            - logical operators:
+                &&   boolean "and"
+                ||   boolean "or"
+            - comparison operators:
+                ==   equal
+                !=   not equal
+                <=   less or equal
+                <    less
+                >=   greater or equal
+                >    greater
+                =~   is matching POSIX extended regex
+                !~   is NOT matching POSIX extended regex
+                ==*  is matching mask, case sensitive (wildcard "*" is allowed)
+                !!*  is NOT matching mask, case sensitive (wildcard "*" is allowed)
+                =*   is matching mask, case insensitive (wildcard "*" is allowed)
+                !*   is NOT matching mask, case insensitive (wildcard "*" is allowed)
+                ==-  is included, case sensitive
+                !!-  is NOT included, case sensitive
+                =-   is included, case insensitive
+                !-   is NOT included, case insensitive
+
+An expression is considered as "true" if it is not NULL, not empty, and different from "0".
+The comparison is made using floating point numbers if the two expressions are valid numbers, with one of the following formats:
+  - integer (examples: 5, -7)
+  - floating point number (examples: 5.2, -7.5, 2.83e-2)
+  - hexadecimal number (examples: 0xA3, -0xA3)
+To force a string comparison, you can add double quotes around each expression, for example:
   50 > 100      ==> 0
   "50" > "100"  ==> 1
 
-Einige Variablen werden im Ausdruck mittels der Formatierung ${variable} ersetzt. Mögliche Variablen sind, nach Reihenfolge ihrer Priorität:
-  1. die Zeichenfolge selbst ohne Auswertung (Format: "raw:xxx")\n
-  2. eine evaluierte Teilzeichenkette (Format: "eval:xxx")
-  3. eine evaluierte Bedingung (Format: "eval_cond:xxx")
-  4. eine Zeichenkette mit Escapesequenzen (Format: "esc:xxx" oder "\xxx")
-  5. Zeichen, die in einer Zeichenkette nicht dargestellt werden sollen (Format: "hide:Zeichen,Zeichenkette")
-  6. eine Zeichenkette mit einer maximalen Anzahl an Zeichen (Format: "cut:max,suffix,string" oder "cut:+max,suffix,string")
-     oder maximale Anzahl an Zeichen die auf dem Bildschirm angezeigt werden sollen (Format: "cutscr:Max,Suffix,Zeichenkette oder "cutscr:+Max,Suffix,Zeichenkette")
-  7. eine Zeichenkette umkehren (Format: "rev:xxx" oder "revscr:xxx")
-  8. eine Zeichenkette wiederholen (Format: "repeat:Anzahl,Zeichenkette")
-  9. Länge einer Zeichenkette (Format: "length:xxx" oder "lengthscr:xxx")
-  10. Aufteilen einer Zeichenkette (Format: "split:Anzahl,Trennzeichen,Flags,xxx")
-  11. Aufteilen von Shell-Argumenten (Format: "split_shell:Anzahl,xxx")
-  12. eine Farbe (Format: "color:xxx", siehe "Anleitung für API Erweiterung", Funktion "color")
-  13. zum modifizieren (Format: "modifier:name,data,string")
-  14. eine Info (Format: "Info:Name,Argumente", Argumente sind optional)
-  15. eine Basis 16/32/64 kodierte / dekodierte Zeichenfolge (Format: "base_encode:base,xxx" oder "base_decode:base,xxx")
-  16. aktuelles Datum/Uhrzeit (Format: "date" oder "date:format")
-  17. eine Umgebungsvariable (Format: "env:XXX")
-  18. ein Dreifachoperand (Format: "if:Bedingung?Wert_falls_wahr:Wert_falls_unwahr")
-  19. Ergebnis eines Ausdrucks mit Klammern und Operatoren + - * / // % ** (Format: "calc:xxx")
-  20. eine zufällige ganze Zahl (Format: "random:min,max")
-  21. eine übersetzte Zeichenkette (Format: "translate:xxx")
-  22. eine Option (Format: "file.section.option")
-  23. eine lokale Variable eines Buffers
-  24. ein(e) hdata - Name/Variable (der Wert wird automatisch in eine Zeichenkette konvertiert), standardmäßig wird für "window" und "buffer" das aktuelle Fenster/Buffer verwendet.
-Das Format für hdata kann wie folgt aufgebaut sein:
-  hdata.var1.var2...: startet mit hdata (der Pointer muss bekannt sein) und fragt eine Variable nach der anderen ab (weitere hdata können folgen)
-  hdata[list].var1.var2...: startet hdata mittels einer Liste, zum Beispiel:
-    ${buffer[gui_buffers].full_name}: der vollständige Name des ersten Buffers, in der verknüpften Liste aller Buffer
-    ${plugin[weechat_plugins].name}: Name der ersten Erweiterung, in der verknüpften Liste aller Erweiterungen
-  hdata[pointer].var1.var2...: startet hdata mittels einem Pointer, zum Beispiel:
-    ${buffer[0x1234abcd].full_name}: vollständiger Name eines Buffers und des dazugehörigen Pointers (kann in triggern benutzt werden)
-    ${buffer[my_pointer].full_name}: vollständiger Name des Buffers mit dem entsprechenden Pointernamen (kann in Triggern verwendet werden)
-Die vorhandenen Namen für hdata und Variablen sind in der "Anleitung für API Erweiterung", Bereich "weechat_hdata_get". beschrieben
-
-Beispiele (einfache Zeichenketten):
-  /eval -n ${raw:${info:version}}                ==> ${info:version}
-  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1
-  /eval -n ${info:version}                       ==> 0.4.3
-  /eval -n ${env:HOME}                           ==> /home/user
-  /eval -n ${weechat.look.scroll_amount}         ==> 3
-  /eval -n ${sec.data.password}                  ==> geheim
-  /eval -n ${window}                             ==> 0x2549aa0
-  /eval -n ${window.buffer}                      ==> 0x2549320
-  /eval -n ${window.buffer.full_name}            ==> core.weechat
-  /eval -n ${window.buffer.number}               ==> 1
-  /eval -n ${\t}                                 ==> <tab>
-  /eval -n ${hide:-,${relay.network.password}}   ==> --------
-  /eval -n ${cut:3,+,test}                       ==> tes+
-  /eval -n ${cut:+3,+,test}                      ==> te+
-  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40
-  /eval -n ${if:${info:term_width}>80?big:small} ==> big
-  /eval -n ${rev:Hello}                          ==> olleH
-  /eval -n ${repeat:5,-}                         ==> -----
-  /eval -n ${length:test}                        ==> 4
-  /eval -n ${split:1,,,abc,def,ghi}              ==> abc
-  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi
-  /eval -n ${split:count,,,abc,def,ghi}          ==> 3
-  /eval -n ${split:random,,,abc,def,ghi}         ==> def
-  /eval -n ${split_shell:1,"arg 1" arg2}         ==> arg 1
-  /eval -n ${split_shell:-1,"arg 1" arg2}        ==> arg2
-  /eval -n ${split_shell:count,"arg 1" arg2}     ==> 2
-  /eval -n ${split_shell:random,"arg 1" arg2}    ==> arg2
-  /eval -n ${calc:(5+2)*3}                       ==> 21
-  /eval -n ${random:0,10}                        ==> 3
-  /eval -n ${base_encode:64,test}                ==> dGVzdA==
-  /eval -n ${base_decode:64,dGVzdA==}            ==> test
-  /eval -n ${translate:Plugin}                   ==> Erweiterung
-
-Beispiele (Bedingungen):
-  /eval -n -c ${window.buffer.number} > 2  ==> 0
-  /eval -n -c ${window.win_width} > 100    ==> 1
-  /eval -n -c (8 > 12) || (5 > 2)          ==> 1
-  /eval -n -c (8 > 12) && (5 > 2)          ==> 0
-  /eval -n -c abcd =~ ^ABC                 ==> 1
-  /eval -n -c abcd =~ (?-i)^ABC            ==> 0
-  /eval -n -c abcd =~ (?-i)^abc            ==> 1
-  /eval -n -c abcd !~ abc                  ==> 0
-  /eval -n -c abcd =* a*d                  ==> 1
-  /eval -n -c abcd =- bc                   ==> 1
+Some variables are replaced in expression, using the format ${variable}, variable can be, by order of priority:
+  1. the string itself without evaluation (format: "raw:xxx")
+  2. a user-defined variable (format: "name")
+  3. an evaluated sub-string (format: "eval:xxx")
+  4. an evaluated condition (format: "eval_cond:xxx")
+  5. a string with escaped chars (format: "esc:xxx" or "\xxx")
+  6. a string with chars to hide (format: "hide:char,string")
+  7. a string with max chars (format: "cut:max,suffix,string" or "cut:+max,suffix,string")
+     or max chars displayed on screen (format: "cutscr:max,suffix,string" or "cutscr:+max,suffix,string")
+  8. a reversed string (format: "rev:xxx" or "revscr:xxx")
+  9. a repeated string (format: "repeat:count,string")
+  10. length of a string (format: "length:xxx" or "lengthscr:xxx")
+  11. split of a string (format: "split:number,separators,flags,xxx")
+  12. split of shell argmuents (format: "split_shell:number,xxx")
+  13. a color (format: "color:xxx", see "Plugin API reference", function "color")
+  14. a modifier (format: "modifier:name,data,string")
+  15. an info (format: "info:name,arguments", arguments are optional)
+  16. a base 16/32/64 encoded/decoded string (format: "base_encode:base,xxx" or "base_decode:base,xxx")
+  17. current date/time (format: "date" or "date:format")
+  18. an environment variable (format: "env:XXX")
+  19. a ternary operator (format: "if:condition?value_if_true:value_if_false")
+  20. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
+  21. a random integer number (format: "random:min,max")
+  22. a translated string (format: "translate:xxx")
+  23. define a user variable (format: "define:name,value")
+  24. an option (format: "file.section.option")
+  25. a local variable in buffer
+  26. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
+Format for hdata can be one of following:
+  hdata.var1.var2...: start with a hdata (pointer must be known), and ask variables one after one (other hdata can be followed)
+  hdata[list].var1.var2...: start with a hdata using a list/pointer/pointer name, for example:
+    ${buffer[gui_buffers].full_name}: full name of first buffer in linked list of buffers
+    ${plugin[weechat_plugins].name}: name of first plugin in linked list of plugins
+  hdata[pointer].var1.var2...: start with a hdata using a pointer, for example:
+    ${buffer[0x1234abcd].full_name}: full name of the buffer with this pointer (can be used in triggers)
+    ${buffer[my_pointer].full_name}: full name of the buffer with this pointer name (can be used in triggers)
+For name of hdata and variables, please look at "Plugin API reference", function "weechat_hdata_get".
+
+Examples (simple strings):
+  /eval -n ${raw:${info:version}}                 ==> ${info:version}
+  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1
+  /eval -n ${info:version}                        ==> 0.4.3
+  /eval -n ${env:HOME}                            ==> /home/user
+  /eval -n ${weechat.look.scroll_amount}          ==> 3
+  /eval -n ${sec.data.password}                   ==> secret
+  /eval -n ${window}                              ==> 0x2549aa0
+  /eval -n ${window.buffer}                       ==> 0x2549320
+  /eval -n ${window.buffer.full_name}             ==> core.weechat
+  /eval -n ${window.buffer.number}                ==> 1
+  /eval -n ${\t}                                  ==> <tab>
+  /eval -n ${hide:-,${relay.network.password}}    ==> --------
+  /eval -n ${cut:3,+,test}                        ==> tes+
+  /eval -n ${cut:+3,+,test}                       ==> te+
+  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40
+  /eval -n ${if:${info:term_width}>80?big:small}  ==> big
+  /eval -n ${rev:Hello}                           ==> olleH
+  /eval -n ${repeat:5,-}                          ==> -----
+  /eval -n ${length:test}                         ==> 4
+  /eval -n ${split:1,,,abc,def,ghi}               ==> abc
+  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi
+  /eval -n ${split:count,,,abc,def,ghi}           ==> 3
+  /eval -n ${split:random,,,abc,def,ghi}          ==> def
+  /eval -n ${split_shell:1,"arg 1" arg2}          ==> arg 1
+  /eval -n ${split_shell:-1,"arg 1" arg2}         ==> arg2
+  /eval -n ${split_shell:count,"arg 1" arg2}      ==> 2
+  /eval -n ${split_shell:random,"arg 1" arg2}     ==> arg2
+  /eval -n ${calc:(5+2)*3}                        ==> 21
+  /eval -n ${random:0,10}                         ==> 3
+  /eval -n ${base_encode:64,test}                 ==> dGVzdA==
+  /eval -n ${base_decode:64,dGVzdA==}             ==> test
+  /eval -n ${translate:Plugin}                    ==> Extension
+  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8
+
+Examples (conditions):
+  /eval -n -c ${window.buffer.number} > 2 ==> 0
+  /eval -n -c ${window.win_width} > 100   ==> 1
+  /eval -n -c (8 > 12) || (5 > 2)         ==> 1
+  /eval -n -c (8 > 12) && (5 > 2)         ==> 0
+  /eval -n -c abcd =~ ^ABC                ==> 1
+  /eval -n -c abcd =~ (?-i)^ABC           ==> 0
+  /eval -n -c abcd =~ (?-i)^abc           ==> 1
+  /eval -n -c abcd !~ abc                 ==> 0
+  /eval -n -c abcd =* a*d                 ==> 1
+  /eval -n -c abcd =- bc                  ==> 1
 ----
 
 [[command_weechat_filter]]
diff --git a/doc/en/includes/autogen_user_commands.en.adoc b/doc/en/includes/autogen_user_commands.en.adoc
index ec823278c..abe5fbf20 100644
--- a/doc/en/includes/autogen_user_commands.en.adoc
+++ b/doc/en/includes/autogen_user_commands.en.adoc
@@ -1375,30 +1375,32 @@ To force a string comparison, you can add double quotes around each expression,
 
 Some variables are replaced in expression, using the format ${variable}, variable can be, by order of priority:
   1. the string itself without evaluation (format: "raw:xxx")
-  2. an evaluated sub-string (format: "eval:xxx")
-  3. an evaluated condition (format: "eval_cond:xxx")
-  4. a string with escaped chars (format: "esc:xxx" or "\xxx")
-  5. a string with chars to hide (format: "hide:char,string")
-  6. a string with max chars (format: "cut:max,suffix,string" or "cut:+max,suffix,string")
+  2. a user-defined variable (format: "name")
+  3. an evaluated sub-string (format: "eval:xxx")
+  4. an evaluated condition (format: "eval_cond:xxx")
+  5. a string with escaped chars (format: "esc:xxx" or "\xxx")
+  6. a string with chars to hide (format: "hide:char,string")
+  7. a string with max chars (format: "cut:max,suffix,string" or "cut:+max,suffix,string")
      or max chars displayed on screen (format: "cutscr:max,suffix,string" or "cutscr:+max,suffix,string")
-  7. a reversed string (format: "rev:xxx" or "revscr:xxx")
-  8. a repeated string (format: "repeat:count,string")
-  9. length of a string (format: "length:xxx" or "lengthscr:xxx")
-  10. split of a string (format: "split:number,separators,flags,xxx")
-  11. split of shell argmuents (format: "split_shell:number,xxx")
-  12. a color (format: "color:xxx", see "Plugin API reference", function "color")
-  13. a modifier (format: "modifier:name,data,string")
-  14. an info (format: "info:name,arguments", arguments are optional)
-  15. a base 16/32/64 encoded/decoded string (format: "base_encode:base,xxx" or "base_decode:base,xxx")
-  16. current date/time (format: "date" or "date:format")
-  17. an environment variable (format: "env:XXX")
-  18. a ternary operator (format: "if:condition?value_if_true:value_if_false")
-  19. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
-  20. a random integer number (format: "random:min,max")
-  21. a translated string (format: "translate:xxx")
-  22. an option (format: "file.section.option")
-  23. a local variable in buffer
-  24. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
+  8. a reversed string (format: "rev:xxx" or "revscr:xxx")
+  9. a repeated string (format: "repeat:count,string")
+  10. length of a string (format: "length:xxx" or "lengthscr:xxx")
+  11. split of a string (format: "split:number,separators,flags,xxx")
+  12. split of shell argmuents (format: "split_shell:number,xxx")
+  13. a color (format: "color:xxx", see "Plugin API reference", function "color")
+  14. a modifier (format: "modifier:name,data,string")
+  15. an info (format: "info:name,arguments", arguments are optional)
+  16. a base 16/32/64 encoded/decoded string (format: "base_encode:base,xxx" or "base_decode:base,xxx")
+  17. current date/time (format: "date" or "date:format")
+  18. an environment variable (format: "env:XXX")
+  19. a ternary operator (format: "if:condition?value_if_true:value_if_false")
+  20. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
+  21. a random integer number (format: "random:min,max")
+  22. a translated string (format: "translate:xxx")
+  23. define a user variable (format: "define:name,value")
+  24. an option (format: "file.section.option")
+  25. a local variable in buffer
+  26. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
 Format for hdata can be one of following:
   hdata.var1.var2...: start with a hdata (pointer must be known), and ask variables one after one (other hdata can be followed)
   hdata[list].var1.var2...: start with a hdata using a list/pointer/pointer name, for example:
@@ -1410,38 +1412,39 @@ Format for hdata can be one of following:
 For name of hdata and variables, please look at "Plugin API reference", function "weechat_hdata_get".
 
 Examples (simple strings):
-  /eval -n ${raw:${info:version}}                ==> ${info:version}
-  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1
-  /eval -n ${info:version}                       ==> 0.4.3
-  /eval -n ${env:HOME}                           ==> /home/user
-  /eval -n ${weechat.look.scroll_amount}         ==> 3
-  /eval -n ${sec.data.password}                  ==> secret
-  /eval -n ${window}                             ==> 0x2549aa0
-  /eval -n ${window.buffer}                      ==> 0x2549320
-  /eval -n ${window.buffer.full_name}            ==> core.weechat
-  /eval -n ${window.buffer.number}               ==> 1
-  /eval -n ${\t}                                 ==> <tab>
-  /eval -n ${hide:-,${relay.network.password}}   ==> --------
-  /eval -n ${cut:3,+,test}                       ==> tes+
-  /eval -n ${cut:+3,+,test}                      ==> te+
-  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40
-  /eval -n ${if:${info:term_width}>80?big:small} ==> big
-  /eval -n ${rev:Hello}                          ==> olleH
-  /eval -n ${repeat:5,-}                         ==> -----
-  /eval -n ${length:test}                        ==> 4
-  /eval -n ${split:1,,,abc,def,ghi}              ==> abc
-  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi
-  /eval -n ${split:count,,,abc,def,ghi}          ==> 3
-  /eval -n ${split:random,,,abc,def,ghi}         ==> def
-  /eval -n ${split_shell:1,"arg 1" arg2}         ==> arg 1
-  /eval -n ${split_shell:-1,"arg 1" arg2}        ==> arg2
-  /eval -n ${split_shell:count,"arg 1" arg2}     ==> 2
-  /eval -n ${split_shell:random,"arg 1" arg2}    ==> arg2
-  /eval -n ${calc:(5+2)*3}                       ==> 21
-  /eval -n ${random:0,10}                        ==> 3
-  /eval -n ${base_encode:64,test}                ==> dGVzdA==
-  /eval -n ${base_decode:64,dGVzdA==}            ==> test
-  /eval -n ${translate:Plugin}                   ==> Extension
+  /eval -n ${raw:${info:version}}                 ==> ${info:version}
+  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1
+  /eval -n ${info:version}                        ==> 0.4.3
+  /eval -n ${env:HOME}                            ==> /home/user
+  /eval -n ${weechat.look.scroll_amount}          ==> 3
+  /eval -n ${sec.data.password}                   ==> secret
+  /eval -n ${window}                              ==> 0x2549aa0
+  /eval -n ${window.buffer}                       ==> 0x2549320
+  /eval -n ${window.buffer.full_name}             ==> core.weechat
+  /eval -n ${window.buffer.number}                ==> 1
+  /eval -n ${\t}                                  ==> <tab>
+  /eval -n ${hide:-,${relay.network.password}}    ==> --------
+  /eval -n ${cut:3,+,test}                        ==> tes+
+  /eval -n ${cut:+3,+,test}                       ==> te+
+  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40
+  /eval -n ${if:${info:term_width}>80?big:small}  ==> big
+  /eval -n ${rev:Hello}                           ==> olleH
+  /eval -n ${repeat:5,-}                          ==> -----
+  /eval -n ${length:test}                         ==> 4
+  /eval -n ${split:1,,,abc,def,ghi}               ==> abc
+  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi
+  /eval -n ${split:count,,,abc,def,ghi}           ==> 3
+  /eval -n ${split:random,,,abc,def,ghi}          ==> def
+  /eval -n ${split_shell:1,"arg 1" arg2}          ==> arg 1
+  /eval -n ${split_shell:-1,"arg 1" arg2}         ==> arg2
+  /eval -n ${split_shell:count,"arg 1" arg2}      ==> 2
+  /eval -n ${split_shell:random,"arg 1" arg2}     ==> arg2
+  /eval -n ${calc:(5+2)*3}                        ==> 21
+  /eval -n ${random:0,10}                         ==> 3
+  /eval -n ${base_encode:64,test}                 ==> dGVzdA==
+  /eval -n ${base_decode:64,dGVzdA==}             ==> test
+  /eval -n ${translate:Plugin}                    ==> Extension
+  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8
 
 Examples (conditions):
   /eval -n -c ${window.buffer.number} > 2 ==> 0
diff --git a/doc/en/weechat_plugin_api.en.adoc b/doc/en/weechat_plugin_api.en.adoc
index b155422d4..1c03e17f9 100644
--- a/doc/en/weechat_plugin_api.en.adoc
+++ b/doc/en/weechat_plugin_api.en.adoc
@@ -2253,7 +2253,7 @@ str3 = weechat.string_input_for_buffer("//test")  # "/test"
 ==== string_eval_expression
 
 _WeeChat ≥ 0.4.0, updated in 0.4.2, 0.4.3, 1.0, 1.1, 1.2, 1.3, 1.6, 1.8, 2.0,
-2.2, 2.3, 2.7, 2.9, 3.1, 3.2 and 3.3._
+2.2, 2.3, 2.7, 2.9, 3.1, 3.2, 3.3 and 3.4._
 
 Evaluate an expression and return result as a string.
 Special variables with format `+${variable}+` are expanded (see table below).
@@ -2574,6 +2574,12 @@ expanded to last):
   `+${raw:${info:version}}+` |
   `+${info:version}+`
 
+| `+${name}+` +
+  _(WeeChat ≥ 3.4)_ |
+  User variable (defined with `+${define:name,value}+`). |
+  `+${name}+` |
+  `+value+`
+
 | `+${name}+` |
   Variable `name` from hashtable _extra_vars_. |
   `+${name}+` |
@@ -2863,6 +2869,13 @@ expanded to last):
   `+${translate:Plugin}+` |
   `+Extension+` (example in French)
 
+| `+${define:name,value}+` +
+  _(WeeChat ≥ 3.4)_ |
+  Define a variable `name` set to `value`, which can then be used in the same
+  evaluated expression with `+${name}+`. |
+  `+${define:len,${calc:5+3}}${len}x${len}+` |
+  `+8x8+`
+
 | `+${sec.data.name}+` |
   Value of the secured data `name`. |
   `+${sec.data.libera_pass}+` |
@@ -2880,7 +2893,7 @@ expanded to last):
 
 | `+${pointer}+` |
   Variable `pointer` from hashtable _pointers_. |
-  `+${my_pointer}+` |
+  `+${buffer}+` |
   `+0x1234abcd+`
 
 | `+${hdata.var1.var2...}+` +
diff --git a/doc/fr/includes/autogen_user_commands.fr.adoc b/doc/fr/includes/autogen_user_commands.fr.adoc
index f8987eb44..dba61e8e2 100644
--- a/doc/fr/includes/autogen_user_commands.fr.adoc
+++ b/doc/fr/includes/autogen_user_commands.fr.adoc
@@ -1375,30 +1375,32 @@ Pour forcer une comparaison de chaînes, vous pouvez ajouter des guillemets auto
 
 Des variables sont remplacées dans l'expression, en utilisant le format ${variable}, la variable pouvant être, par ordre de priorité :
   1. la chaîne elle-même sans évaluation (format : "raw:xxx")
-  2. une sous-chaîne évaluée (format : "eval:xxx")
-  3. une condition évaluée (format : "eval_cond:xxx")
-  4. une chaîne avec les caractères échappés (format : "esc:xxx" ou "\xxx")
-  5. une chaîne avec des caractères à cacher (format : "hide:caractère,chaîne")
-  6. une chaîne avec un maximum de caractères (format : "cut:max,suffixe,chaîne" ou "cut:+max,suffixe,chaîne")
+  2. une variable définie par l'utilisateur (format : "nom")
+  3. une sous-chaîne évaluée (format : "eval:xxx")
+  4. une condition évaluée (format : "eval_cond:xxx")
+  5. une chaîne avec les caractères échappés (format : "esc:xxx" ou "\xxx")
+  6. une chaîne avec des caractères à cacher (format : "hide:caractère,chaîne")
+  7. une chaîne avec un maximum de caractères (format : "cut:max,suffixe,chaîne" ou "cut:+max,suffixe,chaîne")
      ou un maximum de caractères affichés à l'écran (format : "cutscr:max,suffixe,chaîne" ou "cutscr:+max,suffixe,chaîne")
-  7. une chaîne inversée (format : "rev:xxx" ou "revscr:xxx")
-  8. une chaîne répétée (format : "repeat:nombre,chaîne")
-  9. longueur d'une chaîne (format : "length:xxx" ou "lengthscr:xxx")
-  10. découpage d'une chaîne (format : "split:nombre,séparateurs,flags,xxx")
-  11. découpage de paramètres shell (format : "split_shell:nombre,xxx")
-  12. une couleur (format : "color:xxx", voir la "Référence API extension", fonction "color")
-  13. un modificateur (format : "modifier:nom,données,chaîne")
-  14. une info (format : "info:nom,paramètres", les paramètres sont optionnels)
-  15. une chaîne encodée/decodée en base 16, 32 ou 64 (format : "base_encode:base,xxx" ou "base_decode:base,xxx")
-  16. la date/heure courante (format : "date" ou "date:format")
-  17. une variable d'environnement (format : "env:XXX")
-  18. un opérateur ternaire (format : "if:condition?valeur_si_vrai:valeur_si_faux")
-  19. le résultat d'une expression avec parenthèses et les opérateurs + - * / // % ** (format: "calc:xxx")
-  20. un nombre entier aléatoire (format : "random:min,max")
-  21. une chaîne traduite (format : "translate:xxx")
-  22. une option (format : "fichier.section.option")
-  23. une variable locale du tampon
-  24. un hdata/variable (la valeur est automatiquement convertie en chaîne), par défaut "window" et "buffer" pointent vers la fenêtre et le tampon courants.
+  8. une chaîne inversée (format : "rev:xxx" ou "revscr:xxx")
+  9. une chaîne répétée (format : "repeat:nombre,chaîne")
+  10. longueur d'une chaîne (format : "length:xxx" ou "lengthscr:xxx")
+  11. découpage d'une chaîne (format : "split:nombre,séparateurs,flags,xxx")
+  12. découpage de paramètres shell (format : "split_shell:nombre,xxx")
+  13. une couleur (format : "color:xxx", voir la "Référence API extension", fonction "color")
+  14. un modificateur (format : "modifier:nom,données,chaîne")
+  15. une info (format : "info:nom,paramètres", les paramètres sont optionnels)
+  16. une chaîne encodée/decodée en base 16, 32 ou 64 (format : "base_encode:base,xxx" ou "base_decode:base,xxx")
+  17. la date/heure courante (format : "date" ou "date:format")
+  18. une variable d'environnement (format : "env:XXX")
+  19. un opérateur ternaire (format : "if:condition?valeur_si_vrai:valeur_si_faux")
+  20. le résultat d'une expression avec parenthèses et les opérateurs + - * / // % ** (format : "calc:xxx")
+  21. un nombre entier aléatoire (format : "random:min,max")
+  22. une chaîne traduite (format : "translate:xxx")
+  23. déclaration d'une variable utilisateur (format : "define:nom,valeur")
+  24. une option (format : "fichier.section.option")
+  25. une variable locale du tampon
+  26. un hdata/variable (la valeur est automatiquement convertie en chaîne), par défaut "window" et "buffer" pointent vers la fenêtre et le tampon courants.
 Le format du hdata peut être le suivant :
   hdata.var1.var2... : démarrer avec un hdata (le pointeur doit être connu), et demander les variables l'une après l'autre (d'autres hdata peuvent être suivis)
   hdata[liste].var1.var2... : démarrer avec un hdata en utilisant une liste/pointeur/nom de pointeur, par exemple :
@@ -1410,38 +1412,39 @@ Le format du hdata peut être le suivant :
 Pour le nom du hdata et des variables, voir la "Référence API extension", fonction "weechat_hdata_get".
 
 Exemples (chaînes simples) :
-  /eval -n ${raw:${info:version}}                ==> ${info:version}
-  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1
-  /eval -n ${info:version}                       ==> 0.4.3
-  /eval -n ${env:HOME}                           ==> /home/user
-  /eval -n ${weechat.look.scroll_amount}         ==> 3
-  /eval -n ${sec.data.password}                  ==> secret
-  /eval -n ${window}                             ==> 0x2549aa0
-  /eval -n ${window.buffer}                      ==> 0x2549320
-  /eval -n ${window.buffer.full_name}            ==> core.weechat
-  /eval -n ${window.buffer.number}               ==> 1
-  /eval -n ${\t}                                 ==> <tab>
-  /eval -n ${hide:-,${relay.network.password}}   ==> --------
-  /eval -n ${cut:3,+,test}                       ==> tes+
-  /eval -n ${cut:+3,+,test}                      ==> te+
-  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40
-  /eval -n ${if:${info:term_width}>80?big:small} ==> big
-  /eval -n ${rev:Hello}                          ==> olleH
-  /eval -n ${repeat:5,-}                         ==> -----
-  /eval -n ${length:test}                        ==> 4
-  /eval -n ${split:1,,,abc,def,ghi}              ==> abc
-  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi
-  /eval -n ${split:count,,,abc,def,ghi}          ==> 3
-  /eval -n ${split:random,,,abc,def,ghi}         ==> def
-  /eval -n ${split_shell:1,"arg 1" arg2}         ==> arg 1
-  /eval -n ${split_shell:-1,"arg 1" arg2}        ==> arg2
-  /eval -n ${split_shell:count,"arg 1" arg2}     ==> 2
-  /eval -n ${split_shell:random,"arg 1" arg2}    ==> arg2
-  /eval -n ${calc:(5+2)*3}                       ==> 21
-  /eval -n ${random:0,10}                        ==> 3
-  /eval -n ${base_encode:64,test}                ==> dGVzdA==
-  /eval -n ${base_decode:64,dGVzdA==}            ==> test
-  /eval -n ${translate:Plugin}                   ==> Extension
+  /eval -n ${raw:${info:version}}                 ==> ${info:version}
+  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1
+  /eval -n ${info:version}                        ==> 0.4.3
+  /eval -n ${env:HOME}                            ==> /home/user
+  /eval -n ${weechat.look.scroll_amount}          ==> 3
+  /eval -n ${sec.data.password}                   ==> secret
+  /eval -n ${window}                              ==> 0x2549aa0
+  /eval -n ${window.buffer}                       ==> 0x2549320
+  /eval -n ${window.buffer.full_name}             ==> core.weechat
+  /eval -n ${window.buffer.number}                ==> 1
+  /eval -n ${\t}                                  ==> <tab>
+  /eval -n ${hide:-,${relay.network.password}}    ==> --------
+  /eval -n ${cut:3,+,test}                        ==> tes+
+  /eval -n ${cut:+3,+,test}                       ==> te+
+  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40
+  /eval -n ${if:${info:term_width}>80?big:small}  ==> big
+  /eval -n ${rev:Hello}                           ==> olleH
+  /eval -n ${repeat:5,-}                          ==> -----
+  /eval -n ${length:test}                         ==> 4
+  /eval -n ${split:1,,,abc,def,ghi}               ==> abc
+  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi
+  /eval -n ${split:count,,,abc,def,ghi}           ==> 3
+  /eval -n ${split:random,,,abc,def,ghi}          ==> def
+  /eval -n ${split_shell:1,"arg 1" arg2}          ==> arg 1
+  /eval -n ${split_shell:-1,"arg 1" arg2}         ==> arg2
+  /eval -n ${split_shell:count,"arg 1" arg2}      ==> 2
+  /eval -n ${split_shell:random,"arg 1" arg2}     ==> arg2
+  /eval -n ${calc:(5+2)*3}                        ==> 21
+  /eval -n ${random:0,10}                         ==> 3
+  /eval -n ${base_encode:64,test}                 ==> dGVzdA==
+  /eval -n ${base_decode:64,dGVzdA==}             ==> test
+  /eval -n ${translate:Plugin}                    ==> Extension
+  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8
 
 Exemples (conditions) :
   /eval -n -c ${window.buffer.number} > 2 ==> 0
diff --git a/doc/fr/weechat_plugin_api.fr.adoc b/doc/fr/weechat_plugin_api.fr.adoc
index 48ff7cc11..d5e7032a5 100644
--- a/doc/fr/weechat_plugin_api.fr.adoc
+++ b/doc/fr/weechat_plugin_api.fr.adoc
@@ -2291,7 +2291,7 @@ str3 = weechat.string_input_for_buffer("//test")  # "/test"
 ==== string_eval_expression
 
 _WeeChat ≥ 0.4.0, mis à jour dans la 0.4.2, 0.4.3, 1.0, 1.1, 1.2, 1.3, 1.6, 1.8,
-2.0, 2.2, 2.3, 2.7, 2.9, 3.1, 3.2 et 3.3._
+2.0, 2.2, 2.3, 2.7, 2.9, 3.1, 3.2, 3.3 et 3.4._
 
 Évaluer l'expression et retourner le résultat sous forme de chaîne.
 Les variables spéciales avec le format `+${variable}+` sont étendues (voir le
@@ -2618,6 +2618,12 @@ première étendue à la dernière) :
   `+${raw:${info:version}}+` |
   `+${info:version}+`
 
+| `+${nom}+` +
+  _(WeeChat ≥ 3.4)_ |
+  Variable définie par l'utilisateur (avec `+${define:nom,valeur}+`). |
+  `+${nom}+` |
+  `+valeur+`
+
 | `+${nom}+` |
   Variable `nom` de la table de hachage _extra_vars_. |
   `+${nom}+` |
@@ -2910,6 +2916,13 @@ première étendue à la dernière) :
   `+${translate:Plugin}+` |
   `+Extension+` (exemple en Français)
 
+| `+${define:nom,valeur}+` +
+  _(WeeChat ≥ 3.4)_ |
+  Définir une variable `nom` à `valeur`, qui peut être utilisée dans la même
+  expression évaluée avec `+${nom}+`. |
+  `+${define:len,${calc:5+3}}${len}x${len}+` |
+  `+8x8+`
+
 | `+${sec.data.nom}+` |
   Valeur de la donnée sécurisée `nom`. |
   `+${sec.data.libera_pass}+` |
@@ -2927,7 +2940,7 @@ première étendue à la dernière) :
 
 | `+${pointeur}+` |
   Variable `pointeur` de la table de hachage _pointers_. |
-  `+${mon_pointeur}+` |
+  `+${buffer}+` |
   `+0x1234abcd+`
 
 | `+${hdata.var1.var2...}+` +
diff --git a/doc/it/includes/autogen_user_commands.it.adoc b/doc/it/includes/autogen_user_commands.it.adoc
index 640109973..1c66492aa 100644
--- a/doc/it/includes/autogen_user_commands.it.adoc
+++ b/doc/it/includes/autogen_user_commands.it.adoc
@@ -1375,30 +1375,32 @@ To force a string comparison, you can add double quotes around each expression,
 
 Some variables are replaced in expression, using the format ${variable}, variable can be, by order of priority:
   1. the string itself without evaluation (format: "raw:xxx")
-  2. an evaluated sub-string (format: "eval:xxx")
-  3. an evaluated condition (format: "eval_cond:xxx")
-  4. a string with escaped chars (format: "esc:xxx" or "\xxx")
-  5. a string with chars to hide (format: "hide:char,string")
-  6. a string with max chars (format: "cut:max,suffix,string" or "cut:+max,suffix,string")
+  2. a user-defined variable (format: "name")
+  3. an evaluated sub-string (format: "eval:xxx")
+  4. an evaluated condition (format: "eval_cond:xxx")
+  5. a string with escaped chars (format: "esc:xxx" or "\xxx")
+  6. a string with chars to hide (format: "hide:char,string")
+  7. a string with max chars (format: "cut:max,suffix,string" or "cut:+max,suffix,string")
      or max chars displayed on screen (format: "cutscr:max,suffix,string" or "cutscr:+max,suffix,string")
-  7. a reversed string (format: "rev:xxx" or "revscr:xxx")
-  8. a repeated string (format: "repeat:count,string")
-  9. length of a string (format: "length:xxx" or "lengthscr:xxx")
-  10. split of a string (format: "split:number,separators,flags,xxx")
-  11. split of shell argmuents (format: "split_shell:number,xxx")
-  12. a color (format: "color:xxx", see "Plugin API reference", function "color")
-  13. a modifier (format: "modifier:name,data,string")
-  14. an info (format: "info:name,arguments", arguments are optional)
-  15. a base 16/32/64 encoded/decoded string (format: "base_encode:base,xxx" or "base_decode:base,xxx")
-  16. current date/time (format: "date" or "date:format")
-  17. an environment variable (format: "env:XXX")
-  18. a ternary operator (format: "if:condition?value_if_true:value_if_false")
-  19. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
-  20. a random integer number (format: "random:min,max")
-  21. a translated string (format: "translate:xxx")
-  22. an option (format: "file.section.option")
-  23. a local variable in buffer
-  24. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
+  8. a reversed string (format: "rev:xxx" or "revscr:xxx")
+  9. a repeated string (format: "repeat:count,string")
+  10. length of a string (format: "length:xxx" or "lengthscr:xxx")
+  11. split of a string (format: "split:number,separators,flags,xxx")
+  12. split of shell argmuents (format: "split_shell:number,xxx")
+  13. a color (format: "color:xxx", see "Plugin API reference", function "color")
+  14. a modifier (format: "modifier:name,data,string")
+  15. an info (format: "info:name,arguments", arguments are optional)
+  16. a base 16/32/64 encoded/decoded string (format: "base_encode:base,xxx" or "base_decode:base,xxx")
+  17. current date/time (format: "date" or "date:format")
+  18. an environment variable (format: "env:XXX")
+  19. a ternary operator (format: "if:condition?value_if_true:value_if_false")
+  20. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
+  21. a random integer number (format: "random:min,max")
+  22. a translated string (format: "translate:xxx")
+  23. define a user variable (format: "define:name,value")
+  24. an option (format: "file.section.option")
+  25. a local variable in buffer
+  26. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
 Format for hdata can be one of following:
   hdata.var1.var2...: start with a hdata (pointer must be known), and ask variables one after one (other hdata can be followed)
   hdata[list].var1.var2...: start with a hdata using a list/pointer/pointer name, for example:
@@ -1410,38 +1412,39 @@ Format for hdata can be one of following:
 For name of hdata and variables, please look at "Plugin API reference", function "weechat_hdata_get".
 
 Examples (simple strings):
-  /eval -n ${raw:${info:version}}                ==> ${info:version}
-  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1
-  /eval -n ${info:version}                       ==> 0.4.3
-  /eval -n ${env:HOME}                           ==> /home/user
-  /eval -n ${weechat.look.scroll_amount}         ==> 3
-  /eval -n ${sec.data.password}                  ==> secret
-  /eval -n ${window}                             ==> 0x2549aa0
-  /eval -n ${window.buffer}                      ==> 0x2549320
-  /eval -n ${window.buffer.full_name}            ==> core.weechat
-  /eval -n ${window.buffer.number}               ==> 1
-  /eval -n ${\t}                                 ==> <tab>
-  /eval -n ${hide:-,${relay.network.password}}   ==> --------
-  /eval -n ${cut:3,+,test}                       ==> tes+
-  /eval -n ${cut:+3,+,test}                      ==> te+
-  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40
-  /eval -n ${if:${info:term_width}>80?big:small} ==> big
-  /eval -n ${rev:Hello}                          ==> olleH
-  /eval -n ${repeat:5,-}                         ==> -----
-  /eval -n ${length:test}                        ==> 4
-  /eval -n ${split:1,,,abc,def,ghi}              ==> abc
-  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi
-  /eval -n ${split:count,,,abc,def,ghi}          ==> 3
-  /eval -n ${split:random,,,abc,def,ghi}         ==> def
-  /eval -n ${split_shell:1,"arg 1" arg2}         ==> arg 1
-  /eval -n ${split_shell:-1,"arg 1" arg2}        ==> arg2
-  /eval -n ${split_shell:count,"arg 1" arg2}     ==> 2
-  /eval -n ${split_shell:random,"arg 1" arg2}    ==> arg2
-  /eval -n ${calc:(5+2)*3}                       ==> 21
-  /eval -n ${random:0,10}                        ==> 3
-  /eval -n ${base_encode:64,test}                ==> dGVzdA==
-  /eval -n ${base_decode:64,dGVzdA==}            ==> test
-  /eval -n ${translate:Plugin}                   ==> Extension
+  /eval -n ${raw:${info:version}}                 ==> ${info:version}
+  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1
+  /eval -n ${info:version}                        ==> 0.4.3
+  /eval -n ${env:HOME}                            ==> /home/user
+  /eval -n ${weechat.look.scroll_amount}          ==> 3
+  /eval -n ${sec.data.password}                   ==> secret
+  /eval -n ${window}                              ==> 0x2549aa0
+  /eval -n ${window.buffer}                       ==> 0x2549320
+  /eval -n ${window.buffer.full_name}             ==> core.weechat
+  /eval -n ${window.buffer.number}                ==> 1
+  /eval -n ${\t}                                  ==> <tab>
+  /eval -n ${hide:-,${relay.network.password}}    ==> --------
+  /eval -n ${cut:3,+,test}                        ==> tes+
+  /eval -n ${cut:+3,+,test}                       ==> te+
+  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40
+  /eval -n ${if:${info:term_width}>80?big:small}  ==> big
+  /eval -n ${rev:Hello}                           ==> olleH
+  /eval -n ${repeat:5,-}                          ==> -----
+  /eval -n ${length:test}                         ==> 4
+  /eval -n ${split:1,,,abc,def,ghi}               ==> abc
+  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi
+  /eval -n ${split:count,,,abc,def,ghi}           ==> 3
+  /eval -n ${split:random,,,abc,def,ghi}          ==> def
+  /eval -n ${split_shell:1,"arg 1" arg2}          ==> arg 1
+  /eval -n ${split_shell:-1,"arg 1" arg2}         ==> arg2
+  /eval -n ${split_shell:count,"arg 1" arg2}      ==> 2
+  /eval -n ${split_shell:random,"arg 1" arg2}     ==> arg2
+  /eval -n ${calc:(5+2)*3}                        ==> 21
+  /eval -n ${random:0,10}                         ==> 3
+  /eval -n ${base_encode:64,test}                 ==> dGVzdA==
+  /eval -n ${base_decode:64,dGVzdA==}             ==> test
+  /eval -n ${translate:Plugin}                    ==> Extension
+  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8
 
 Examples (conditions):
   /eval -n -c ${window.buffer.number} > 2 ==> 0
diff --git a/doc/it/weechat_plugin_api.it.adoc b/doc/it/weechat_plugin_api.it.adoc
index 1c35f0ed9..4719ae3bc 100644
--- a/doc/it/weechat_plugin_api.it.adoc
+++ b/doc/it/weechat_plugin_api.it.adoc
@@ -2351,7 +2351,7 @@ str3 = weechat.string_input_for_buffer("//test")  # "/test"
 ==== string_eval_expression
 
 _WeeChat ≥ 0.4.0, updated in 0.4.2, 0.4.3, 1.0, 1.1, 1.2, 1.3, 1.6, 1.8, 2.0,
-2.2, 2.3, 2.7, 2.9, 3.1, 3.2 and 3.3._
+2.2, 2.3, 2.7, 2.9, 3.1, 3.2, 3.3 and 3.4._
 
 Evaluate an expression and return result as a string.
 Special variables with format `+${variable}+` are expanded (see table below).
@@ -2672,6 +2672,12 @@ expanded to last):
   `+${raw:${info:version}}+` |
   `+${info:version}+`
 
+| `+${name}+` +
+  _(WeeChat ≥ 3.4)_ |
+  User variable (defined with `+${define:name,value}+`). |
+  `+${name}+` |
+  `+value+`
+
 | `+${name}+` |
   Variable `name` from hashtable _extra_vars_. |
   `+${name}+` |
@@ -2960,6 +2966,13 @@ expanded to last):
   `+${translate:Plugin}+` |
   `+Extension+` (example in French)
 
+| `+${define:name,value}+` +
+  _(WeeChat ≥ 3.4)_ |
+  Define a variable `name` set to `value`, which can then be used in the same
+  evaluated expression with `+${name}+`. |
+  `+${define:len,${calc:5+3}}${len}x${len}+` |
+  `+8x8+`
+
 | `+${sec.data.name}+` |
   Value of the secured data `name`. |
   `+${sec.data.libera_pass}+` |
@@ -2977,7 +2990,7 @@ expanded to last):
 
 | `+${pointer}+` |
   Variable `pointer` from hashtable _pointers_. |
-  `+${my_pointer}+` |
+  `+${buffer}+` |
   `+0x1234abcd+`
 
 | `+${hdata.var1.var2...}+` +
diff --git a/doc/ja/includes/autogen_user_commands.ja.adoc b/doc/ja/includes/autogen_user_commands.ja.adoc
index f5040b9da..988be618e 100644
--- a/doc/ja/includes/autogen_user_commands.ja.adoc
+++ b/doc/ja/includes/autogen_user_commands.ja.adoc
@@ -1375,30 +1375,32 @@ To force a string comparison, you can add double quotes around each expression,
 
 Some variables are replaced in expression, using the format ${variable}, variable can be, by order of priority:
   1. the string itself without evaluation (format: "raw:xxx")
-  2. an evaluated sub-string (format: "eval:xxx")
-  3. an evaluated condition (format: "eval_cond:xxx")
-  4. a string with escaped chars (format: "esc:xxx" or "\xxx")
-  5. a string with chars to hide (format: "hide:char,string")
-  6. a string with max chars (format: "cut:max,suffix,string" or "cut:+max,suffix,string")
+  2. a user-defined variable (format: "name")
+  3. an evaluated sub-string (format: "eval:xxx")
+  4. an evaluated condition (format: "eval_cond:xxx")
+  5. a string with escaped chars (format: "esc:xxx" or "\xxx")
+  6. a string with chars to hide (format: "hide:char,string")
+  7. a string with max chars (format: "cut:max,suffix,string" or "cut:+max,suffix,string")
      or max chars displayed on screen (format: "cutscr:max,suffix,string" or "cutscr:+max,suffix,string")
-  7. a reversed string (format: "rev:xxx" or "revscr:xxx")
-  8. a repeated string (format: "repeat:count,string")
-  9. length of a string (format: "length:xxx" or "lengthscr:xxx")
-  10. split of a string (format: "split:number,separators,flags,xxx")
-  11. split of shell argmuents (format: "split_shell:number,xxx")
-  12. a color (format: "color:xxx", see "Plugin API reference", function "color")
-  13. a modifier (format: "modifier:name,data,string")
-  14. an info (format: "info:name,arguments", arguments are optional)
-  15. a base 16/32/64 encoded/decoded string (format: "base_encode:base,xxx" or "base_decode:base,xxx")
-  16. current date/time (format: "date" or "date:format")
-  17. an environment variable (format: "env:XXX")
-  18. a ternary operator (format: "if:condition?value_if_true:value_if_false")
-  19. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
-  20. a random integer number (format: "random:min,max")
-  21. a translated string (format: "translate:xxx")
-  22. an option (format: "file.section.option")
-  23. a local variable in buffer
-  24. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
+  8. a reversed string (format: "rev:xxx" or "revscr:xxx")
+  9. a repeated string (format: "repeat:count,string")
+  10. length of a string (format: "length:xxx" or "lengthscr:xxx")
+  11. split of a string (format: "split:number,separators,flags,xxx")
+  12. split of shell argmuents (format: "split_shell:number,xxx")
+  13. a color (format: "color:xxx", see "Plugin API reference", function "color")
+  14. a modifier (format: "modifier:name,data,string")
+  15. an info (format: "info:name,arguments", arguments are optional)
+  16. a base 16/32/64 encoded/decoded string (format: "base_encode:base,xxx" or "base_decode:base,xxx")
+  17. current date/time (format: "date" or "date:format")
+  18. an environment variable (format: "env:XXX")
+  19. a ternary operator (format: "if:condition?value_if_true:value_if_false")
+  20. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
+  21. a random integer number (format: "random:min,max")
+  22. a translated string (format: "translate:xxx")
+  23. define a user variable (format: "define:name,value")
+  24. an option (format: "file.section.option")
+  25. a local variable in buffer
+  26. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
 Format for hdata can be one of following:
   hdata.var1.var2...: start with a hdata (pointer must be known), and ask variables one after one (other hdata can be followed)
   hdata[list].var1.var2...: start with a hdata using a list/pointer/pointer name, for example:
@@ -1410,38 +1412,39 @@ Format for hdata can be one of following:
 For name of hdata and variables, please look at "Plugin API reference", function "weechat_hdata_get".
 
 Examples (simple strings):
-  /eval -n ${raw:${info:version}}                ==> ${info:version}
-  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1
-  /eval -n ${info:version}                       ==> 0.4.3
-  /eval -n ${env:HOME}                           ==> /home/user
-  /eval -n ${weechat.look.scroll_amount}         ==> 3
-  /eval -n ${sec.data.password}                  ==> secret
-  /eval -n ${window}                             ==> 0x2549aa0
-  /eval -n ${window.buffer}                      ==> 0x2549320
-  /eval -n ${window.buffer.full_name}            ==> core.weechat
-  /eval -n ${window.buffer.number}               ==> 1
-  /eval -n ${\t}                                 ==> <tab>
-  /eval -n ${hide:-,${relay.network.password}}   ==> --------
-  /eval -n ${cut:3,+,test}                       ==> tes+
-  /eval -n ${cut:+3,+,test}                      ==> te+
-  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40
-  /eval -n ${if:${info:term_width}>80?big:small} ==> big
-  /eval -n ${rev:Hello}                          ==> olleH
-  /eval -n ${repeat:5,-}                         ==> -----
-  /eval -n ${length:test}                        ==> 4
-  /eval -n ${split:1,,,abc,def,ghi}              ==> abc
-  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi
-  /eval -n ${split:count,,,abc,def,ghi}          ==> 3
-  /eval -n ${split:random,,,abc,def,ghi}         ==> def
-  /eval -n ${split_shell:1,"arg 1" arg2}         ==> arg 1
-  /eval -n ${split_shell:-1,"arg 1" arg2}        ==> arg2
-  /eval -n ${split_shell:count,"arg 1" arg2}     ==> 2
-  /eval -n ${split_shell:random,"arg 1" arg2}    ==> arg2
-  /eval -n ${calc:(5+2)*3}                       ==> 21
-  /eval -n ${random:0,10}                        ==> 3
-  /eval -n ${base_encode:64,test}                ==> dGVzdA==
-  /eval -n ${base_decode:64,dGVzdA==}            ==> test
-  /eval -n ${translate:Plugin}                   ==> Extension
+  /eval -n ${raw:${info:version}}                 ==> ${info:version}
+  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1
+  /eval -n ${info:version}                        ==> 0.4.3
+  /eval -n ${env:HOME}                            ==> /home/user
+  /eval -n ${weechat.look.scroll_amount}          ==> 3
+  /eval -n ${sec.data.password}                   ==> secret
+  /eval -n ${window}                              ==> 0x2549aa0
+  /eval -n ${window.buffer}                       ==> 0x2549320
+  /eval -n ${window.buffer.full_name}             ==> core.weechat
+  /eval -n ${window.buffer.number}                ==> 1
+  /eval -n ${\t}                                  ==> <tab>
+  /eval -n ${hide:-,${relay.network.password}}    ==> --------
+  /eval -n ${cut:3,+,test}                        ==> tes+
+  /eval -n ${cut:+3,+,test}                       ==> te+
+  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40
+  /eval -n ${if:${info:term_width}>80?big:small}  ==> big
+  /eval -n ${rev:Hello}                           ==> olleH
+  /eval -n ${repeat:5,-}                          ==> -----
+  /eval -n ${length:test}                         ==> 4
+  /eval -n ${split:1,,,abc,def,ghi}               ==> abc
+  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi
+  /eval -n ${split:count,,,abc,def,ghi}           ==> 3
+  /eval -n ${split:random,,,abc,def,ghi}          ==> def
+  /eval -n ${split_shell:1,"arg 1" arg2}          ==> arg 1
+  /eval -n ${split_shell:-1,"arg 1" arg2}         ==> arg2
+  /eval -n ${split_shell:count,"arg 1" arg2}      ==> 2
+  /eval -n ${split_shell:random,"arg 1" arg2}     ==> arg2
+  /eval -n ${calc:(5+2)*3}                        ==> 21
+  /eval -n ${random:0,10}                         ==> 3
+  /eval -n ${base_encode:64,test}                 ==> dGVzdA==
+  /eval -n ${base_decode:64,dGVzdA==}             ==> test
+  /eval -n ${translate:Plugin}                    ==> Extension
+  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8
 
 Examples (conditions):
   /eval -n -c ${window.buffer.number} > 2 ==> 0
diff --git a/doc/ja/weechat_plugin_api.ja.adoc b/doc/ja/weechat_plugin_api.ja.adoc
index a6f1f1439..e14463d1f 100644
--- a/doc/ja/weechat_plugin_api.ja.adoc
+++ b/doc/ja/weechat_plugin_api.ja.adoc
@@ -2274,7 +2274,7 @@ str3 = weechat.string_input_for_buffer("//test")  # "/test"
 
 // TRANSLATION MISSING
 _WeeChat ≥ 0.4.0, updated in 0.4.2, 0.4.3, 1.0, 1.1, 1.2, 1.3, 1.6, 1.8, 2.0,
-2.2, 2.3, 2.7, 2.9, 3.1, 3.2 and 3.3._
+2.2, 2.3, 2.7, 2.9, 3.1, 3.2, 3.3 and 3.4._
 
 式を評価して文字列として返す。`+${variable}+`
 という書式で書かれた特殊変数は展開されます (以下の表を参照)。
@@ -2603,6 +2603,13 @@ str5 = weechat.string_eval_expression("password=abc password=def", {}, {}, optio
   `+${raw:${info:version}}+` |
   `+${info:version}+`
 
+// TRANSLATION MISSING
+| `+${name}+` +
+  _(WeeChat ≥ 3.4)_ |
+  User variable (defined with `+${define:name,value}+`). |
+  `+${name}+` |
+  `+value+`
+
 | `+${name}+` |
   _extra_vars_ の変数 `name` の値に展開 |
   `+${name}+` |
@@ -2907,6 +2914,14 @@ str5 = weechat.string_eval_expression("password=abc password=def", {}, {}, optio
   `+${translate:Plugin}+` |
   `+Extension+` (example in French)
 
+// TRANSLATION MISSING
+| `+${define:name,value}+` +
+  _(WeeChat ≥ 3.4)_ |
+  Define a variable `name` set to `value`, which can then be used in the same
+  evaluated expression with `+${name}+`. |
+  `+${define:len,${calc:5+3}}${len}x${len}+` |
+  `+8x8+`
+
 | `+${sec.data.name}+` |
   セキュアデータ `name` の値 |
   `+${sec.data.libera_pass}+` |
@@ -2924,7 +2939,7 @@ str5 = weechat.string_eval_expression("password=abc password=def", {}, {}, optio
 
 | `+${pointer}+` |
   _pointers_ の変数 `pointer` の値に展開 |
-  `+${my_pointer}+` |
+  `+${buffer}+` |
   `+0x1234abcd+`
 
 // TRANSLATION MISSING
diff --git a/doc/pl/includes/autogen_user_commands.pl.adoc b/doc/pl/includes/autogen_user_commands.pl.adoc
index fb4416d22..c514e76b9 100644
--- a/doc/pl/includes/autogen_user_commands.pl.adoc
+++ b/doc/pl/includes/autogen_user_commands.pl.adoc
@@ -1374,30 +1374,32 @@ To force a string comparison, you can add double quotes around each expression,
 
 Some variables are replaced in expression, using the format ${variable}, variable can be, by order of priority:
   1. the string itself without evaluation (format: "raw:xxx")
-  2. an evaluated sub-string (format: "eval:xxx")
-  3. an evaluated condition (format: "eval_cond:xxx")
-  4. a string with escaped chars (format: "esc:xxx" or "\xxx")
-  5. a string with chars to hide (format: "hide:char,string")
-  6. a string with max chars (format: "cut:max,suffix,string" or "cut:+max,suffix,string")
+  2. a user-defined variable (format: "name")
+  3. an evaluated sub-string (format: "eval:xxx")
+  4. an evaluated condition (format: "eval_cond:xxx")
+  5. a string with escaped chars (format: "esc:xxx" or "\xxx")
+  6. a string with chars to hide (format: "hide:char,string")
+  7. a string with max chars (format: "cut:max,suffix,string" or "cut:+max,suffix,string")
      or max chars displayed on screen (format: "cutscr:max,suffix,string" or "cutscr:+max,suffix,string")
-  7. a reversed string (format: "rev:xxx" or "revscr:xxx")
-  8. a repeated string (format: "repeat:count,string")
-  9. length of a string (format: "length:xxx" or "lengthscr:xxx")
-  10. split of a string (format: "split:number,separators,flags,xxx")
-  11. split of shell argmuents (format: "split_shell:number,xxx")
-  12. a color (format: "color:xxx", see "Plugin API reference", function "color")
-  13. a modifier (format: "modifier:name,data,string")
-  14. an info (format: "info:name,arguments", arguments are optional)
-  15. a base 16/32/64 encoded/decoded string (format: "base_encode:base,xxx" or "base_decode:base,xxx")
-  16. current date/time (format: "date" or "date:format")
-  17. an environment variable (format: "env:XXX")
-  18. a ternary operator (format: "if:condition?value_if_true:value_if_false")
-  19. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
-  20. a random integer number (format: "random:min,max")
-  21. a translated string (format: "translate:xxx")
-  22. an option (format: "file.section.option")
-  23. a local variable in buffer
-  24. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
+  8. a reversed string (format: "rev:xxx" or "revscr:xxx")
+  9. a repeated string (format: "repeat:count,string")
+  10. length of a string (format: "length:xxx" or "lengthscr:xxx")
+  11. split of a string (format: "split:number,separators,flags,xxx")
+  12. split of shell argmuents (format: "split_shell:number,xxx")
+  13. a color (format: "color:xxx", see "Plugin API reference", function "color")
+  14. a modifier (format: "modifier:name,data,string")
+  15. an info (format: "info:name,arguments", arguments are optional)
+  16. a base 16/32/64 encoded/decoded string (format: "base_encode:base,xxx" or "base_decode:base,xxx")
+  17. current date/time (format: "date" or "date:format")
+  18. an environment variable (format: "env:XXX")
+  19. a ternary operator (format: "if:condition?value_if_true:value_if_false")
+  20. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
+  21. a random integer number (format: "random:min,max")
+  22. a translated string (format: "translate:xxx")
+  23. define a user variable (format: "define:name,value")
+  24. an option (format: "file.section.option")
+  25. a local variable in buffer
+  26. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
 Format for hdata can be one of following:
   hdata.var1.var2...: start with a hdata (pointer must be known), and ask variables one after one (other hdata can be followed)
   hdata[list].var1.var2...: start with a hdata using a list/pointer/pointer name, for example:
@@ -1409,38 +1411,39 @@ Format for hdata can be one of following:
 For name of hdata and variables, please look at "Plugin API reference", function "weechat_hdata_get".
 
 Examples (simple strings):
-  /eval -n ${raw:${info:version}}                ==> ${info:version}
-  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1
-  /eval -n ${info:version}                       ==> 0.4.3
-  /eval -n ${env:HOME}                           ==> /home/user
-  /eval -n ${weechat.look.scroll_amount}         ==> 3
-  /eval -n ${sec.data.password}                  ==> secret
-  /eval -n ${window}                             ==> 0x2549aa0
-  /eval -n ${window.buffer}                      ==> 0x2549320
-  /eval -n ${window.buffer.full_name}            ==> core.weechat
-  /eval -n ${window.buffer.number}               ==> 1
-  /eval -n ${\t}                                 ==> <tab>
-  /eval -n ${hide:-,${relay.network.password}}   ==> --------
-  /eval -n ${cut:3,+,test}                       ==> tes+
-  /eval -n ${cut:+3,+,test}                      ==> te+
-  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40
-  /eval -n ${if:${info:term_width}>80?big:small} ==> big
-  /eval -n ${rev:Hello}                          ==> olleH
-  /eval -n ${repeat:5,-}                         ==> -----
-  /eval -n ${length:test}                        ==> 4
-  /eval -n ${split:1,,,abc,def,ghi}              ==> abc
-  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi
-  /eval -n ${split:count,,,abc,def,ghi}          ==> 3
-  /eval -n ${split:random,,,abc,def,ghi}         ==> def
-  /eval -n ${split_shell:1,"arg 1" arg2}         ==> arg 1
-  /eval -n ${split_shell:-1,"arg 1" arg2}        ==> arg2
-  /eval -n ${split_shell:count,"arg 1" arg2}     ==> 2
-  /eval -n ${split_shell:random,"arg 1" arg2}    ==> arg2
-  /eval -n ${calc:(5+2)*3}                       ==> 21
-  /eval -n ${random:0,10}                        ==> 3
-  /eval -n ${base_encode:64,test}                ==> dGVzdA==
-  /eval -n ${base_decode:64,dGVzdA==}            ==> test
-  /eval -n ${translate:Plugin}                   ==> Extension
+  /eval -n ${raw:${info:version}}                 ==> ${info:version}
+  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1
+  /eval -n ${info:version}                        ==> 0.4.3
+  /eval -n ${env:HOME}                            ==> /home/user
+  /eval -n ${weechat.look.scroll_amount}          ==> 3
+  /eval -n ${sec.data.password}                   ==> secret
+  /eval -n ${window}                              ==> 0x2549aa0
+  /eval -n ${window.buffer}                       ==> 0x2549320
+  /eval -n ${window.buffer.full_name}             ==> core.weechat
+  /eval -n ${window.buffer.number}                ==> 1
+  /eval -n ${\t}                                  ==> <tab>
+  /eval -n ${hide:-,${relay.network.password}}    ==> --------
+  /eval -n ${cut:3,+,test}                        ==> tes+
+  /eval -n ${cut:+3,+,test}                       ==> te+
+  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40
+  /eval -n ${if:${info:term_width}>80?big:small}  ==> big
+  /eval -n ${rev:Hello}                           ==> olleH
+  /eval -n ${repeat:5,-}                          ==> -----
+  /eval -n ${length:test}                         ==> 4
+  /eval -n ${split:1,,,abc,def,ghi}               ==> abc
+  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi
+  /eval -n ${split:count,,,abc,def,ghi}           ==> 3
+  /eval -n ${split:random,,,abc,def,ghi}          ==> def
+  /eval -n ${split_shell:1,"arg 1" arg2}          ==> arg 1
+  /eval -n ${split_shell:-1,"arg 1" arg2}         ==> arg2
+  /eval -n ${split_shell:count,"arg 1" arg2}      ==> 2
+  /eval -n ${split_shell:random,"arg 1" arg2}     ==> arg2
+  /eval -n ${calc:(5+2)*3}                        ==> 21
+  /eval -n ${random:0,10}                         ==> 3
+  /eval -n ${base_encode:64,test}                 ==> dGVzdA==
+  /eval -n ${base_decode:64,dGVzdA==}             ==> test
+  /eval -n ${translate:Plugin}                    ==> Extension
+  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8
 
 Examples (conditions):
   /eval -n -c ${window.buffer.number} > 2 ==> 0
diff --git a/doc/sr/includes/autogen_user_commands.sr.adoc b/doc/sr/includes/autogen_user_commands.sr.adoc
index e0c84dbfd..5cf00a51e 100644
--- a/doc/sr/includes/autogen_user_commands.sr.adoc
+++ b/doc/sr/includes/autogen_user_commands.sr.adoc
@@ -1375,30 +1375,32 @@ To force a string comparison, you can add double quotes around each expression,
 
 Some variables are replaced in expression, using the format ${variable}, variable can be, by order of priority:
   1. the string itself without evaluation (format: "raw:xxx")
-  2. an evaluated sub-string (format: "eval:xxx")
-  3. an evaluated condition (format: "eval_cond:xxx")
-  4. a string with escaped chars (format: "esc:xxx" or "\xxx")
-  5. a string with chars to hide (format: "hide:char,string")
-  6. a string with max chars (format: "cut:max,suffix,string" or "cut:+max,suffix,string")
+  2. a user-defined variable (format: "name")
+  3. an evaluated sub-string (format: "eval:xxx")
+  4. an evaluated condition (format: "eval_cond:xxx")
+  5. a string with escaped chars (format: "esc:xxx" or "\xxx")
+  6. a string with chars to hide (format: "hide:char,string")
+  7. a string with max chars (format: "cut:max,suffix,string" or "cut:+max,suffix,string")
      or max chars displayed on screen (format: "cutscr:max,suffix,string" or "cutscr:+max,suffix,string")
-  7. a reversed string (format: "rev:xxx" or "revscr:xxx")
-  8. a repeated string (format: "repeat:count,string")
-  9. length of a string (format: "length:xxx" or "lengthscr:xxx")
-  10. split of a string (format: "split:number,separators,flags,xxx")
-  11. split of shell argmuents (format: "split_shell:number,xxx")
-  12. a color (format: "color:xxx", see "Plugin API reference", function "color")
-  13. a modifier (format: "modifier:name,data,string")
-  14. an info (format: "info:name,arguments", arguments are optional)
-  15. a base 16/32/64 encoded/decoded string (format: "base_encode:base,xxx" or "base_decode:base,xxx")
-  16. current date/time (format: "date" or "date:format")
-  17. an environment variable (format: "env:XXX")
-  18. a ternary operator (format: "if:condition?value_if_true:value_if_false")
-  19. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
-  20. a random integer number (format: "random:min,max")
-  21. a translated string (format: "translate:xxx")
-  22. an option (format: "file.section.option")
-  23. a local variable in buffer
-  24. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
+  8. a reversed string (format: "rev:xxx" or "revscr:xxx")
+  9. a repeated string (format: "repeat:count,string")
+  10. length of a string (format: "length:xxx" or "lengthscr:xxx")
+  11. split of a string (format: "split:number,separators,flags,xxx")
+  12. split of shell argmuents (format: "split_shell:number,xxx")
+  13. a color (format: "color:xxx", see "Plugin API reference", function "color")
+  14. a modifier (format: "modifier:name,data,string")
+  15. an info (format: "info:name,arguments", arguments are optional)
+  16. a base 16/32/64 encoded/decoded string (format: "base_encode:base,xxx" or "base_decode:base,xxx")
+  17. current date/time (format: "date" or "date:format")
+  18. an environment variable (format: "env:XXX")
+  19. a ternary operator (format: "if:condition?value_if_true:value_if_false")
+  20. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
+  21. a random integer number (format: "random:min,max")
+  22. a translated string (format: "translate:xxx")
+  23. define a user variable (format: "define:name,value")
+  24. an option (format: "file.section.option")
+  25. a local variable in buffer
+  26. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
 Format for hdata can be one of following:
   hdata.var1.var2...: start with a hdata (pointer must be known), and ask variables one after one (other hdata can be followed)
   hdata[list].var1.var2...: start with a hdata using a list/pointer/pointer name, for example:
@@ -1410,38 +1412,39 @@ Format for hdata can be one of following:
 For name of hdata and variables, please look at "Plugin API reference", function "weechat_hdata_get".
 
 Examples (simple strings):
-  /eval -n ${raw:${info:version}}                ==> ${info:version}
-  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1
-  /eval -n ${info:version}                       ==> 0.4.3
-  /eval -n ${env:HOME}                           ==> /home/user
-  /eval -n ${weechat.look.scroll_amount}         ==> 3
-  /eval -n ${sec.data.password}                  ==> secret
-  /eval -n ${window}                             ==> 0x2549aa0
-  /eval -n ${window.buffer}                      ==> 0x2549320
-  /eval -n ${window.buffer.full_name}            ==> core.weechat
-  /eval -n ${window.buffer.number}               ==> 1
-  /eval -n ${\t}                                 ==> <tab>
-  /eval -n ${hide:-,${relay.network.password}}   ==> --------
-  /eval -n ${cut:3,+,test}                       ==> tes+
-  /eval -n ${cut:+3,+,test}                      ==> te+
-  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40
-  /eval -n ${if:${info:term_width}>80?big:small} ==> big
-  /eval -n ${rev:Hello}                          ==> olleH
-  /eval -n ${repeat:5,-}                         ==> -----
-  /eval -n ${length:test}                        ==> 4
-  /eval -n ${split:1,,,abc,def,ghi}              ==> abc
-  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi
-  /eval -n ${split:count,,,abc,def,ghi}          ==> 3
-  /eval -n ${split:random,,,abc,def,ghi}         ==> def
-  /eval -n ${split_shell:1,"arg 1" arg2}         ==> arg 1
-  /eval -n ${split_shell:-1,"arg 1" arg2}        ==> arg2
-  /eval -n ${split_shell:count,"arg 1" arg2}     ==> 2
-  /eval -n ${split_shell:random,"arg 1" arg2}    ==> arg2
-  /eval -n ${calc:(5+2)*3}                       ==> 21
-  /eval -n ${random:0,10}                        ==> 3
-  /eval -n ${base_encode:64,test}                ==> dGVzdA==
-  /eval -n ${base_decode:64,dGVzdA==}            ==> test
-  /eval -n ${translate:Plugin}                   ==> Extension
+  /eval -n ${raw:${info:version}}                 ==> ${info:version}
+  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1
+  /eval -n ${info:version}                        ==> 0.4.3
+  /eval -n ${env:HOME}                            ==> /home/user
+  /eval -n ${weechat.look.scroll_amount}          ==> 3
+  /eval -n ${sec.data.password}                   ==> secret
+  /eval -n ${window}                              ==> 0x2549aa0
+  /eval -n ${window.buffer}                       ==> 0x2549320
+  /eval -n ${window.buffer.full_name}             ==> core.weechat
+  /eval -n ${window.buffer.number}                ==> 1
+  /eval -n ${\t}                                  ==> <tab>
+  /eval -n ${hide:-,${relay.network.password}}    ==> --------
+  /eval -n ${cut:3,+,test}                        ==> tes+
+  /eval -n ${cut:+3,+,test}                       ==> te+
+  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40
+  /eval -n ${if:${info:term_width}>80?big:small}  ==> big
+  /eval -n ${rev:Hello}                           ==> olleH
+  /eval -n ${repeat:5,-}                          ==> -----
+  /eval -n ${length:test}                         ==> 4
+  /eval -n ${split:1,,,abc,def,ghi}               ==> abc
+  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi
+  /eval -n ${split:count,,,abc,def,ghi}           ==> 3
+  /eval -n ${split:random,,,abc,def,ghi}          ==> def
+  /eval -n ${split_shell:1,"arg 1" arg2}          ==> arg 1
+  /eval -n ${split_shell:-1,"arg 1" arg2}         ==> arg2
+  /eval -n ${split_shell:count,"arg 1" arg2}      ==> 2
+  /eval -n ${split_shell:random,"arg 1" arg2}     ==> arg2
+  /eval -n ${calc:(5+2)*3}                        ==> 21
+  /eval -n ${random:0,10}                         ==> 3
+  /eval -n ${base_encode:64,test}                 ==> dGVzdA==
+  /eval -n ${base_decode:64,dGVzdA==}             ==> test
+  /eval -n ${translate:Plugin}                    ==> Extension
+  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8
 
 Examples (conditions):
   /eval -n -c ${window.buffer.number} > 2 ==> 0
diff --git a/doc/sr/weechat_plugin_api.sr.adoc b/doc/sr/weechat_plugin_api.sr.adoc
index 1146dbaa2..0d324de14 100644
--- a/doc/sr/weechat_plugin_api.sr.adoc
+++ b/doc/sr/weechat_plugin_api.sr.adoc
@@ -2159,7 +2159,7 @@ str3 = weechat.string_input_for_buffer("//test")  # "/test"
 
 ==== string_eval_expression
 
-_WeeChat ≥ 0.4.0, ажурирано у верзијама 0.4.2, 0.4.3, 1.0, 1.1, 1.2, 1.3, 1.6, 1.8, 2.0, 2.2, 2.3, 2.7, 2.9, 3.1, 3.2 и 3.3._
+_WeeChat ≥ 0.4.0, ажурирано у верзијама 0.4.2, 0.4.3, 1.0, 1.1, 1.2, 1.3, 1.6, 1.8, 2.0, 2.2, 2.3, 2.7, 2.9, 3.1, 3.2, 3.3 и 3.4._
 
 Израчунава израз и враћа вредност као стринг. Специјалне променљиве у формату `+${променљива}+` се развијају (погледајте табелу испод).
 
@@ -2457,6 +2457,13 @@ str5 = weechat.string_eval_expression("password=abc password=def", {}, {}, optio
   `+${raw:${info:version}}+` |
   `+${info:version}+`
 
+// TRANSLATION MISSING
+| `+${name}+` +
+  _(WeeChat ≥ 3.4)_ |
+  User variable (defined with `+${define:name,value}+`). |
+  `+${name}+` |
+  `+value+`
+
 | `+${име}+` |
   Променљива `name` из хеш табеле _extra_vars_. |
   `+${име}+` |
@@ -2748,6 +2755,14 @@ str5 = weechat.string_eval_expression("password=abc password=def", {}, {}, optio
   `+${translate:Plugin}+` |
   `+Extension+` (пример из француског)
 
+// TRANSLATION MISSING
+| `+${define:name,value}+` +
+  _(WeeChat ≥ 3.4)_ |
+  Define a variable `name` set to `value`, which can then be used in the same
+  evaluated expression with `+${name}+`. |
+  `+${define:len,${calc:5+3}}${len}x${len}+` |
+  `+8x8+`
+
 | `+${sec.data.име}+` |
   Вредност обезбеђених података `име`. |
   `+${sec.data.libera_pass}+` |
@@ -2765,7 +2780,7 @@ str5 = weechat.string_eval_expression("password=abc password=def", {}, {}, optio
 
 | `+${pointer}+` |
   Променљива `pointer` из хеш табеле _pointers_. |
-  `+${my_pointer}+` |
+  `+${buffer}+` |
   `+0x1234abcd+`
 
 | `+${hdata.пром1.пром2...}+` +
diff --git a/po/cs.po b/po/cs.po
index 44d9ae629..7c9557476 100644
--- a/po/cs.po
+++ b/po/cs.po
@@ -21,7 +21,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2021-09-09 21:07+0200\n"
+"POT-Creation-Date: 2021-09-20 21:12+0200\n"
 "PO-Revision-Date: 2021-07-10 16:01+0200\n"
 "Last-Translator: Ondřej Súkup <mimi.vx@gmail.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -1599,36 +1599,38 @@ msgid ""
 "Some variables are replaced in expression, using the format ${variable}, "
 "variable can be, by order of priority:\n"
 "  1. the string itself without evaluation (format: \"raw:xxx\")\n"
-"  2. an evaluated sub-string (format: \"eval:xxx\")\n"
-"  3. an evaluated condition (format: \"eval_cond:xxx\")\n"
-"  4. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
-"  5. a string with chars to hide (format: \"hide:char,string\")\n"
-"  6. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
+"  2. a user-defined variable (format: \"name\")\n"
+"  3. an evaluated sub-string (format: \"eval:xxx\")\n"
+"  4. an evaluated condition (format: \"eval_cond:xxx\")\n"
+"  5. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
+"  6. a string with chars to hide (format: \"hide:char,string\")\n"
+"  7. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
 "+max,suffix,string\")\n"
 "     or max chars displayed on screen (format: \"cutscr:max,suffix,string\" "
 "or \"cutscr:+max,suffix,string\")\n"
-"  7. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
-"  8. a repeated string (format: \"repeat:count,string\")\n"
-"  9. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
-"  10. split of a string (format: \"split:number,separators,flags,xxx\")\n"
-"  11. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
-"  12. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
+"  8. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
+"  9. a repeated string (format: \"repeat:count,string\")\n"
+"  10. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
+"  11. split of a string (format: \"split:number,separators,flags,xxx\")\n"
+"  12. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
+"  13. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
 "\"color\")\n"
-"  13. a modifier (format: \"modifier:name,data,string\")\n"
-"  14. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  15. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"  14. a modifier (format: \"modifier:name,data,string\")\n"
+"  15. an info (format: \"info:name,arguments\", arguments are optional)\n"
+"  16. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
 "\" or \"base_decode:base,xxx\")\n"
-"  16. current date/time (format: \"date\" or \"date:format\")\n"
-"  17. an environment variable (format: \"env:XXX\")\n"
-"  18. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  17. current date/time (format: \"date\" or \"date:format\")\n"
+"  18. an environment variable (format: \"env:XXX\")\n"
+"  19. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  19. result of an expression with parentheses and operators + - * / // % ** "
+"  20. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  20. a random integer number (format: \"random:min,max\")\n"
-"  21. a translated string (format: \"translate:xxx\")\n"
-"  22. an option (format: \"file.section.option\")\n"
-"  23. a local variable in buffer\n"
-"  24. a hdata name/variable (the value is automatically converted to "
+"  21. a random integer number (format: \"random:min,max\")\n"
+"  22. a translated string (format: \"translate:xxx\")\n"
+"  23. define a user variable (format: \"define:name,value\")\n"
+"  24. an option (format: \"file.section.option\")\n"
+"  25. a local variable in buffer\n"
+"  26. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1650,38 +1652,39 @@ msgid ""
 "function \"weechat_hdata_get\".\n"
 "\n"
 "Examples (simple strings):\n"
-"  /eval -n ${raw:${info:version}}                ==> ${info:version}\n"
-"  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1\n"
-"  /eval -n ${info:version}                       ==> 0.4.3\n"
-"  /eval -n ${env:HOME}                           ==> /home/user\n"
-"  /eval -n ${weechat.look.scroll_amount}         ==> 3\n"
-"  /eval -n ${sec.data.password}                  ==> secret\n"
-"  /eval -n ${window}                             ==> 0x2549aa0\n"
-"  /eval -n ${window.buffer}                      ==> 0x2549320\n"
-"  /eval -n ${window.buffer.full_name}            ==> core.weechat\n"
-"  /eval -n ${window.buffer.number}               ==> 1\n"
-"  /eval -n ${\\t}                                 ==> <tab>\n"
-"  /eval -n ${hide:-,${relay.network.password}}   ==> --------\n"
-"  /eval -n ${cut:3,+,test}                       ==> tes+\n"
-"  /eval -n ${cut:+3,+,test}                      ==> te+\n"
-"  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40\n"
-"  /eval -n ${if:${info:term_width}>80?big:small} ==> big\n"
-"  /eval -n ${rev:Hello}                          ==> olleH\n"
-"  /eval -n ${repeat:5,-}                         ==> -----\n"
-"  /eval -n ${length:test}                        ==> 4\n"
-"  /eval -n ${split:1,,,abc,def,ghi}              ==> abc\n"
-"  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi\n"
-"  /eval -n ${split:count,,,abc,def,ghi}          ==> 3\n"
-"  /eval -n ${split:random,,,abc,def,ghi}         ==> def\n"
-"  /eval -n ${split_shell:1,\"arg 1\" arg2}         ==> arg 1\n"
-"  /eval -n ${split_shell:-1,\"arg 1\" arg2}        ==> arg2\n"
-"  /eval -n ${split_shell:count,\"arg 1\" arg2}     ==> 2\n"
-"  /eval -n ${split_shell:random,\"arg 1\" arg2}    ==> arg2\n"
-"  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
-"  /eval -n ${random:0,10}                        ==> 3\n"
-"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
-"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
-"  /eval -n ${translate:Plugin}                   ==> Extension\n"
+"  /eval -n ${raw:${info:version}}                 ==> ${info:version}\n"
+"  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1\n"
+"  /eval -n ${info:version}                        ==> 0.4.3\n"
+"  /eval -n ${env:HOME}                            ==> /home/user\n"
+"  /eval -n ${weechat.look.scroll_amount}          ==> 3\n"
+"  /eval -n ${sec.data.password}                   ==> secret\n"
+"  /eval -n ${window}                              ==> 0x2549aa0\n"
+"  /eval -n ${window.buffer}                       ==> 0x2549320\n"
+"  /eval -n ${window.buffer.full_name}             ==> core.weechat\n"
+"  /eval -n ${window.buffer.number}                ==> 1\n"
+"  /eval -n ${\\t}                                  ==> <tab>\n"
+"  /eval -n ${hide:-,${relay.network.password}}    ==> --------\n"
+"  /eval -n ${cut:3,+,test}                        ==> tes+\n"
+"  /eval -n ${cut:+3,+,test}                       ==> te+\n"
+"  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40\n"
+"  /eval -n ${if:${info:term_width}>80?big:small}  ==> big\n"
+"  /eval -n ${rev:Hello}                           ==> olleH\n"
+"  /eval -n ${repeat:5,-}                          ==> -----\n"
+"  /eval -n ${length:test}                         ==> 4\n"
+"  /eval -n ${split:1,,,abc,def,ghi}               ==> abc\n"
+"  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi\n"
+"  /eval -n ${split:count,,,abc,def,ghi}           ==> 3\n"
+"  /eval -n ${split:random,,,abc,def,ghi}          ==> def\n"
+"  /eval -n ${split_shell:1,\"arg 1\" arg2}          ==> arg 1\n"
+"  /eval -n ${split_shell:-1,\"arg 1\" arg2}         ==> arg2\n"
+"  /eval -n ${split_shell:count,\"arg 1\" arg2}      ==> 2\n"
+"  /eval -n ${split_shell:random,\"arg 1\" arg2}     ==> arg2\n"
+"  /eval -n ${calc:(5+2)*3}                        ==> 21\n"
+"  /eval -n ${random:0,10}                         ==> 3\n"
+"  /eval -n ${base_encode:64,test}                 ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}             ==> test\n"
+"  /eval -n ${translate:Plugin}                    ==> Extension\n"
+"  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/de.po b/po/de.po
index 994a76aa1..e40b6a0fc 100644
--- a/po/de.po
+++ b/po/de.po
@@ -24,7 +24,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2021-09-09 21:07+0200\n"
+"POT-Creation-Date: 2021-09-20 21:12+0200\n"
 "PO-Revision-Date: 2021-09-10 09:56+0200\n"
 "Last-Translator: Nils Görs <weechatter@arcor.de>\n"
 "Language-Team: German <kde-i18n-de@kde.org>\n"
@@ -1689,6 +1689,153 @@ msgstr ""
 "[-n|-s] [-d] <expression> || [-n] [-d [-d]] -c <expression1> <operator> "
 "<expression2>"
 
+#, fuzzy
+#| msgid ""
+#| "        -n: display result without sending it to buffer (debug mode)\n"
+#| "        -s: split expression before evaluating it (many commands can be "
+#| "separated by semicolons)\n"
+#| "        -d: display debug output after evaluation (with two -d: more "
+#| "verbose debug)\n"
+#| "        -c: evaluate as condition: use operators and parentheses, return "
+#| "a boolean value (\"0\" or \"1\")\n"
+#| "expression: expression to evaluate, variables with format ${variable} are "
+#| "replaced (see below); many commands can be separated by semicolons\n"
+#| "  operator: a logical or comparison operator:\n"
+#| "            - logical operators:\n"
+#| "                &&   boolean \"and\"\n"
+#| "                ||   boolean \"or\"\n"
+#| "            - comparison operators:\n"
+#| "                ==   equal\n"
+#| "                !=   not equal\n"
+#| "                <=   less or equal\n"
+#| "                <    less\n"
+#| "                >=   greater or equal\n"
+#| "                >    greater\n"
+#| "                =~   is matching POSIX extended regex\n"
+#| "                !~   is NOT matching POSIX extended regex\n"
+#| "                ==*  is matching mask, case sensitive (wildcard \"*\" is "
+#| "allowed)\n"
+#| "                !!*  is NOT matching mask, case sensitive (wildcard \"*\" "
+#| "is allowed)\n"
+#| "                =*   is matching mask, case insensitive (wildcard \"*\" "
+#| "is allowed)\n"
+#| "                !*   is NOT matching mask, case insensitive (wildcard \"*"
+#| "\" is allowed)\n"
+#| "                ==-  is included, case sensitive\n"
+#| "                !!-  is NOT included, case sensitive\n"
+#| "                =-   is included, case insensitive\n"
+#| "                !-   is NOT included, case insensitive\n"
+#| "\n"
+#| "An expression is considered as \"true\" if it is not NULL, not empty, and "
+#| "different from \"0\".\n"
+#| "The comparison is made using floating point numbers if the two "
+#| "expressions are valid numbers, with one of the following formats:\n"
+#| "  - integer (examples: 5, -7)\n"
+#| "  - floating point number (examples: 5.2, -7.5, 2.83e-2)\n"
+#| "  - hexadecimal number (examples: 0xA3, -0xA3)\n"
+#| "To force a string comparison, you can add double quotes around each "
+#| "expression, for example:\n"
+#| "  50 > 100      ==> 0\n"
+#| "  \"50\" > \"100\"  ==> 1\n"
+#| "\n"
+#| "Some variables are replaced in expression, using the format ${variable}, "
+#| "variable can be, by order of priority:\n"
+#| "  1. the string itself without evaluation (format: \"raw:xxx\")\n"
+#| "  2. an evaluated sub-string (format: \"eval:xxx\")\n"
+#| "  3. an evaluated condition (format: \"eval_cond:xxx\")\n"
+#| "  4. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
+#| "  5. a string with chars to hide (format: \"hide:char,string\")\n"
+#| "  6. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
+#| "+max,suffix,string\")\n"
+#| "     or max chars displayed on screen (format: \"cutscr:max,suffix,string"
+#| "\" or \"cutscr:+max,suffix,string\")\n"
+#| "  7. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
+#| "  8. a repeated string (format: \"repeat:count,string\")\n"
+#| "  9. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
+#| "  10. split of a string (format: \"split:number,separators,flags,xxx\")\n"
+#| "  11. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
+#| "  12. a color (format: \"color:xxx\", see \"Plugin API reference\", "
+#| "function \"color\")\n"
+#| "  13. a modifier (format: \"modifier:name,data,string\")\n"
+#| "  14. an info (format: \"info:name,arguments\", arguments are optional)\n"
+#| "  15. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,"
+#| "xxx\" or \"base_decode:base,xxx\")\n"
+#| "  16. current date/time (format: \"date\" or \"date:format\")\n"
+#| "  17. an environment variable (format: \"env:XXX\")\n"
+#| "  18. a ternary operator (format: \"if:condition?value_if_true:"
+#| "value_if_false\")\n"
+#| "  19. result of an expression with parentheses and operators + - * / // % "
+#| "** (format: \"calc:xxx\")\n"
+#| "  20. a random integer number (format: \"random:min,max\")\n"
+#| "  21. a translated string (format: \"translate:xxx\")\n"
+#| "  22. an option (format: \"file.section.option\")\n"
+#| "  23. a local variable in buffer\n"
+#| "  24. a hdata name/variable (the value is automatically converted to "
+#| "string), by default \"window\" and \"buffer\" point to current window/"
+#| "buffer.\n"
+#| "Format for hdata can be one of following:\n"
+#| "  hdata.var1.var2...: start with a hdata (pointer must be known), and ask "
+#| "variables one after one (other hdata can be followed)\n"
+#| "  hdata[list].var1.var2...: start with a hdata using a list/pointer/"
+#| "pointer name, for example:\n"
+#| "    ${buffer[gui_buffers].full_name}: full name of first buffer in linked "
+#| "list of buffers\n"
+#| "    ${plugin[weechat_plugins].name}: name of first plugin in linked list "
+#| "of plugins\n"
+#| "  hdata[pointer].var1.var2...: start with a hdata using a pointer, for "
+#| "example:\n"
+#| "    ${buffer[0x1234abcd].full_name}: full name of the buffer with this "
+#| "pointer (can be used in triggers)\n"
+#| "    ${buffer[my_pointer].full_name}: full name of the buffer with this "
+#| "pointer name (can be used in triggers)\n"
+#| "For name of hdata and variables, please look at \"Plugin API reference\", "
+#| "function \"weechat_hdata_get\".\n"
+#| "\n"
+#| "Examples (simple strings):\n"
+#| "  /eval -n ${raw:${info:version}}                ==> ${info:version}\n"
+#| "  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1\n"
+#| "  /eval -n ${info:version}                       ==> 0.4.3\n"
+#| "  /eval -n ${env:HOME}                           ==> /home/user\n"
+#| "  /eval -n ${weechat.look.scroll_amount}         ==> 3\n"
+#| "  /eval -n ${sec.data.password}                  ==> secret\n"
+#| "  /eval -n ${window}                             ==> 0x2549aa0\n"
+#| "  /eval -n ${window.buffer}                      ==> 0x2549320\n"
+#| "  /eval -n ${window.buffer.full_name}            ==> core.weechat\n"
+#| "  /eval -n ${window.buffer.number}               ==> 1\n"
+#| "  /eval -n ${\\t}                                 ==> <tab>\n"
+#| "  /eval -n ${hide:-,${relay.network.password}}   ==> --------\n"
+#| "  /eval -n ${cut:3,+,test}                       ==> tes+\n"
+#| "  /eval -n ${cut:+3,+,test}                      ==> te+\n"
+#| "  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40\n"
+#| "  /eval -n ${if:${info:term_width}>80?big:small} ==> big\n"
+#| "  /eval -n ${rev:Hello}                          ==> olleH\n"
+#| "  /eval -n ${repeat:5,-}                         ==> -----\n"
+#| "  /eval -n ${length:test}                        ==> 4\n"
+#| "  /eval -n ${split:1,,,abc,def,ghi}              ==> abc\n"
+#| "  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi\n"
+#| "  /eval -n ${split:count,,,abc,def,ghi}          ==> 3\n"
+#| "  /eval -n ${split:random,,,abc,def,ghi}         ==> def\n"
+#| "  /eval -n ${split_shell:1,\"arg 1\" arg2}         ==> arg 1\n"
+#| "  /eval -n ${split_shell:-1,\"arg 1\" arg2}        ==> arg2\n"
+#| "  /eval -n ${split_shell:count,\"arg 1\" arg2}     ==> 2\n"
+#| "  /eval -n ${split_shell:random,\"arg 1\" arg2}    ==> arg2\n"
+#| "  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
+#| "  /eval -n ${random:0,10}                        ==> 3\n"
+#| "  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
+#| "  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
+#| "  /eval -n ${translate:Plugin}                   ==> Extension\n"
+#| "\n"
+#| "Examples (conditions):\n"
+#| "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
+#| "  /eval -n -c ${window.win_width} > 100   ==> 1\n"
+#| "  /eval -n -c (8 > 12) || (5 > 2)         ==> 1\n"
+#| "  /eval -n -c (8 > 12) && (5 > 2)         ==> 0\n"
+#| "  /eval -n -c abcd =~ ^ABC                ==> 1\n"
+#| "  /eval -n -c abcd =~ (?-i)^ABC           ==> 0\n"
+#| "  /eval -n -c abcd =~ (?-i)^abc           ==> 1\n"
+#| "  /eval -n -c abcd !~ abc                 ==> 0\n"
+#| "  /eval -n -c abcd =* a*d                 ==> 1\n"
+#| "  /eval -n -c abcd =- bc                  ==> 1"
 msgid ""
 "        -n: display result without sending it to buffer (debug mode)\n"
 "        -s: split expression before evaluating it (many commands can be "
@@ -1740,36 +1887,38 @@ msgid ""
 "Some variables are replaced in expression, using the format ${variable}, "
 "variable can be, by order of priority:\n"
 "  1. the string itself without evaluation (format: \"raw:xxx\")\n"
-"  2. an evaluated sub-string (format: \"eval:xxx\")\n"
-"  3. an evaluated condition (format: \"eval_cond:xxx\")\n"
-"  4. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
-"  5. a string with chars to hide (format: \"hide:char,string\")\n"
-"  6. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
+"  2. a user-defined variable (format: \"name\")\n"
+"  3. an evaluated sub-string (format: \"eval:xxx\")\n"
+"  4. an evaluated condition (format: \"eval_cond:xxx\")\n"
+"  5. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
+"  6. a string with chars to hide (format: \"hide:char,string\")\n"
+"  7. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
 "+max,suffix,string\")\n"
 "     or max chars displayed on screen (format: \"cutscr:max,suffix,string\" "
 "or \"cutscr:+max,suffix,string\")\n"
-"  7. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
-"  8. a repeated string (format: \"repeat:count,string\")\n"
-"  9. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
-"  10. split of a string (format: \"split:number,separators,flags,xxx\")\n"
-"  11. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
-"  12. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
+"  8. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
+"  9. a repeated string (format: \"repeat:count,string\")\n"
+"  10. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
+"  11. split of a string (format: \"split:number,separators,flags,xxx\")\n"
+"  12. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
+"  13. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
 "\"color\")\n"
-"  13. a modifier (format: \"modifier:name,data,string\")\n"
-"  14. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  15. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"  14. a modifier (format: \"modifier:name,data,string\")\n"
+"  15. an info (format: \"info:name,arguments\", arguments are optional)\n"
+"  16. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
 "\" or \"base_decode:base,xxx\")\n"
-"  16. current date/time (format: \"date\" or \"date:format\")\n"
-"  17. an environment variable (format: \"env:XXX\")\n"
-"  18. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  17. current date/time (format: \"date\" or \"date:format\")\n"
+"  18. an environment variable (format: \"env:XXX\")\n"
+"  19. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  19. result of an expression with parentheses and operators + - * / // % ** "
+"  20. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  20. a random integer number (format: \"random:min,max\")\n"
-"  21. a translated string (format: \"translate:xxx\")\n"
-"  22. an option (format: \"file.section.option\")\n"
-"  23. a local variable in buffer\n"
-"  24. a hdata name/variable (the value is automatically converted to "
+"  21. a random integer number (format: \"random:min,max\")\n"
+"  22. a translated string (format: \"translate:xxx\")\n"
+"  23. define a user variable (format: \"define:name,value\")\n"
+"  24. an option (format: \"file.section.option\")\n"
+"  25. a local variable in buffer\n"
+"  26. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1791,38 +1940,39 @@ msgid ""
 "function \"weechat_hdata_get\".\n"
 "\n"
 "Examples (simple strings):\n"
-"  /eval -n ${raw:${info:version}}                ==> ${info:version}\n"
-"  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1\n"
-"  /eval -n ${info:version}                       ==> 0.4.3\n"
-"  /eval -n ${env:HOME}                           ==> /home/user\n"
-"  /eval -n ${weechat.look.scroll_amount}         ==> 3\n"
-"  /eval -n ${sec.data.password}                  ==> secret\n"
-"  /eval -n ${window}                             ==> 0x2549aa0\n"
-"  /eval -n ${window.buffer}                      ==> 0x2549320\n"
-"  /eval -n ${window.buffer.full_name}            ==> core.weechat\n"
-"  /eval -n ${window.buffer.number}               ==> 1\n"
-"  /eval -n ${\\t}                                 ==> <tab>\n"
-"  /eval -n ${hide:-,${relay.network.password}}   ==> --------\n"
-"  /eval -n ${cut:3,+,test}                       ==> tes+\n"
-"  /eval -n ${cut:+3,+,test}                      ==> te+\n"
-"  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40\n"
-"  /eval -n ${if:${info:term_width}>80?big:small} ==> big\n"
-"  /eval -n ${rev:Hello}                          ==> olleH\n"
-"  /eval -n ${repeat:5,-}                         ==> -----\n"
-"  /eval -n ${length:test}                        ==> 4\n"
-"  /eval -n ${split:1,,,abc,def,ghi}              ==> abc\n"
-"  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi\n"
-"  /eval -n ${split:count,,,abc,def,ghi}          ==> 3\n"
-"  /eval -n ${split:random,,,abc,def,ghi}         ==> def\n"
-"  /eval -n ${split_shell:1,\"arg 1\" arg2}         ==> arg 1\n"
-"  /eval -n ${split_shell:-1,\"arg 1\" arg2}        ==> arg2\n"
-"  /eval -n ${split_shell:count,\"arg 1\" arg2}     ==> 2\n"
-"  /eval -n ${split_shell:random,\"arg 1\" arg2}    ==> arg2\n"
-"  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
-"  /eval -n ${random:0,10}                        ==> 3\n"
-"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
-"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
-"  /eval -n ${translate:Plugin}                   ==> Extension\n"
+"  /eval -n ${raw:${info:version}}                 ==> ${info:version}\n"
+"  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1\n"
+"  /eval -n ${info:version}                        ==> 0.4.3\n"
+"  /eval -n ${env:HOME}                            ==> /home/user\n"
+"  /eval -n ${weechat.look.scroll_amount}          ==> 3\n"
+"  /eval -n ${sec.data.password}                   ==> secret\n"
+"  /eval -n ${window}                              ==> 0x2549aa0\n"
+"  /eval -n ${window.buffer}                       ==> 0x2549320\n"
+"  /eval -n ${window.buffer.full_name}             ==> core.weechat\n"
+"  /eval -n ${window.buffer.number}                ==> 1\n"
+"  /eval -n ${\\t}                                  ==> <tab>\n"
+"  /eval -n ${hide:-,${relay.network.password}}    ==> --------\n"
+"  /eval -n ${cut:3,+,test}                        ==> tes+\n"
+"  /eval -n ${cut:+3,+,test}                       ==> te+\n"
+"  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40\n"
+"  /eval -n ${if:${info:term_width}>80?big:small}  ==> big\n"
+"  /eval -n ${rev:Hello}                           ==> olleH\n"
+"  /eval -n ${repeat:5,-}                          ==> -----\n"
+"  /eval -n ${length:test}                         ==> 4\n"
+"  /eval -n ${split:1,,,abc,def,ghi}               ==> abc\n"
+"  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi\n"
+"  /eval -n ${split:count,,,abc,def,ghi}           ==> 3\n"
+"  /eval -n ${split:random,,,abc,def,ghi}          ==> def\n"
+"  /eval -n ${split_shell:1,\"arg 1\" arg2}          ==> arg 1\n"
+"  /eval -n ${split_shell:-1,\"arg 1\" arg2}         ==> arg2\n"
+"  /eval -n ${split_shell:count,\"arg 1\" arg2}      ==> 2\n"
+"  /eval -n ${split_shell:random,\"arg 1\" arg2}     ==> arg2\n"
+"  /eval -n ${calc:(5+2)*3}                        ==> 21\n"
+"  /eval -n ${random:0,10}                         ==> 3\n"
+"  /eval -n ${base_encode:64,test}                 ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}             ==> test\n"
+"  /eval -n ${translate:Plugin}                    ==> Extension\n"
+"  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
@@ -2629,9 +2779,6 @@ msgstr ""
 msgid "list/load/unload plugins"
 msgstr "Erweiterungen verwalten (auflisten/installieren/beenden)"
 
-#| msgid ""
-#| "list|listfull [<name>] || load <filename> [<arguments>] || autoload "
-#| "[<arguments>] || reload [<name>|* [<arguments>]] || unload [<name>]"
 msgid ""
 "list [-o|-ol|-i|-il|<name>] || listfull [<name>] || load <filename> "
 "[<arguments>] || autoload [<arguments>] || reload [<name>|* [<arguments>]] "
diff --git a/po/es.po b/po/es.po
index 271b801ac..fa7272b8b 100644
--- a/po/es.po
+++ b/po/es.po
@@ -22,7 +22,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2021-09-09 21:07+0200\n"
+"POT-Creation-Date: 2021-09-20 21:12+0200\n"
 "PO-Revision-Date: 2021-07-10 16:01+0200\n"
 "Last-Translator: Elián Hanisch <lambdae2@gmail.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -1627,36 +1627,38 @@ msgid ""
 "Some variables are replaced in expression, using the format ${variable}, "
 "variable can be, by order of priority:\n"
 "  1. the string itself without evaluation (format: \"raw:xxx\")\n"
-"  2. an evaluated sub-string (format: \"eval:xxx\")\n"
-"  3. an evaluated condition (format: \"eval_cond:xxx\")\n"
-"  4. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
-"  5. a string with chars to hide (format: \"hide:char,string\")\n"
-"  6. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
+"  2. a user-defined variable (format: \"name\")\n"
+"  3. an evaluated sub-string (format: \"eval:xxx\")\n"
+"  4. an evaluated condition (format: \"eval_cond:xxx\")\n"
+"  5. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
+"  6. a string with chars to hide (format: \"hide:char,string\")\n"
+"  7. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
 "+max,suffix,string\")\n"
 "     or max chars displayed on screen (format: \"cutscr:max,suffix,string\" "
 "or \"cutscr:+max,suffix,string\")\n"
-"  7. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
-"  8. a repeated string (format: \"repeat:count,string\")\n"
-"  9. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
-"  10. split of a string (format: \"split:number,separators,flags,xxx\")\n"
-"  11. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
-"  12. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
+"  8. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
+"  9. a repeated string (format: \"repeat:count,string\")\n"
+"  10. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
+"  11. split of a string (format: \"split:number,separators,flags,xxx\")\n"
+"  12. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
+"  13. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
 "\"color\")\n"
-"  13. a modifier (format: \"modifier:name,data,string\")\n"
-"  14. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  15. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"  14. a modifier (format: \"modifier:name,data,string\")\n"
+"  15. an info (format: \"info:name,arguments\", arguments are optional)\n"
+"  16. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
 "\" or \"base_decode:base,xxx\")\n"
-"  16. current date/time (format: \"date\" or \"date:format\")\n"
-"  17. an environment variable (format: \"env:XXX\")\n"
-"  18. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  17. current date/time (format: \"date\" or \"date:format\")\n"
+"  18. an environment variable (format: \"env:XXX\")\n"
+"  19. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  19. result of an expression with parentheses and operators + - * / // % ** "
+"  20. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  20. a random integer number (format: \"random:min,max\")\n"
-"  21. a translated string (format: \"translate:xxx\")\n"
-"  22. an option (format: \"file.section.option\")\n"
-"  23. a local variable in buffer\n"
-"  24. a hdata name/variable (the value is automatically converted to "
+"  21. a random integer number (format: \"random:min,max\")\n"
+"  22. a translated string (format: \"translate:xxx\")\n"
+"  23. define a user variable (format: \"define:name,value\")\n"
+"  24. an option (format: \"file.section.option\")\n"
+"  25. a local variable in buffer\n"
+"  26. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1678,38 +1680,39 @@ msgid ""
 "function \"weechat_hdata_get\".\n"
 "\n"
 "Examples (simple strings):\n"
-"  /eval -n ${raw:${info:version}}                ==> ${info:version}\n"
-"  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1\n"
-"  /eval -n ${info:version}                       ==> 0.4.3\n"
-"  /eval -n ${env:HOME}                           ==> /home/user\n"
-"  /eval -n ${weechat.look.scroll_amount}         ==> 3\n"
-"  /eval -n ${sec.data.password}                  ==> secret\n"
-"  /eval -n ${window}                             ==> 0x2549aa0\n"
-"  /eval -n ${window.buffer}                      ==> 0x2549320\n"
-"  /eval -n ${window.buffer.full_name}            ==> core.weechat\n"
-"  /eval -n ${window.buffer.number}               ==> 1\n"
-"  /eval -n ${\\t}                                 ==> <tab>\n"
-"  /eval -n ${hide:-,${relay.network.password}}   ==> --------\n"
-"  /eval -n ${cut:3,+,test}                       ==> tes+\n"
-"  /eval -n ${cut:+3,+,test}                      ==> te+\n"
-"  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40\n"
-"  /eval -n ${if:${info:term_width}>80?big:small} ==> big\n"
-"  /eval -n ${rev:Hello}                          ==> olleH\n"
-"  /eval -n ${repeat:5,-}                         ==> -----\n"
-"  /eval -n ${length:test}                        ==> 4\n"
-"  /eval -n ${split:1,,,abc,def,ghi}              ==> abc\n"
-"  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi\n"
-"  /eval -n ${split:count,,,abc,def,ghi}          ==> 3\n"
-"  /eval -n ${split:random,,,abc,def,ghi}         ==> def\n"
-"  /eval -n ${split_shell:1,\"arg 1\" arg2}         ==> arg 1\n"
-"  /eval -n ${split_shell:-1,\"arg 1\" arg2}        ==> arg2\n"
-"  /eval -n ${split_shell:count,\"arg 1\" arg2}     ==> 2\n"
-"  /eval -n ${split_shell:random,\"arg 1\" arg2}    ==> arg2\n"
-"  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
-"  /eval -n ${random:0,10}                        ==> 3\n"
-"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
-"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
-"  /eval -n ${translate:Plugin}                   ==> Extension\n"
+"  /eval -n ${raw:${info:version}}                 ==> ${info:version}\n"
+"  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1\n"
+"  /eval -n ${info:version}                        ==> 0.4.3\n"
+"  /eval -n ${env:HOME}                            ==> /home/user\n"
+"  /eval -n ${weechat.look.scroll_amount}          ==> 3\n"
+"  /eval -n ${sec.data.password}                   ==> secret\n"
+"  /eval -n ${window}                              ==> 0x2549aa0\n"
+"  /eval -n ${window.buffer}                       ==> 0x2549320\n"
+"  /eval -n ${window.buffer.full_name}             ==> core.weechat\n"
+"  /eval -n ${window.buffer.number}                ==> 1\n"
+"  /eval -n ${\\t}                                  ==> <tab>\n"
+"  /eval -n ${hide:-,${relay.network.password}}    ==> --------\n"
+"  /eval -n ${cut:3,+,test}                        ==> tes+\n"
+"  /eval -n ${cut:+3,+,test}                       ==> te+\n"
+"  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40\n"
+"  /eval -n ${if:${info:term_width}>80?big:small}  ==> big\n"
+"  /eval -n ${rev:Hello}                           ==> olleH\n"
+"  /eval -n ${repeat:5,-}                          ==> -----\n"
+"  /eval -n ${length:test}                         ==> 4\n"
+"  /eval -n ${split:1,,,abc,def,ghi}               ==> abc\n"
+"  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi\n"
+"  /eval -n ${split:count,,,abc,def,ghi}           ==> 3\n"
+"  /eval -n ${split:random,,,abc,def,ghi}          ==> def\n"
+"  /eval -n ${split_shell:1,\"arg 1\" arg2}          ==> arg 1\n"
+"  /eval -n ${split_shell:-1,\"arg 1\" arg2}         ==> arg2\n"
+"  /eval -n ${split_shell:count,\"arg 1\" arg2}      ==> 2\n"
+"  /eval -n ${split_shell:random,\"arg 1\" arg2}     ==> arg2\n"
+"  /eval -n ${calc:(5+2)*3}                        ==> 21\n"
+"  /eval -n ${random:0,10}                         ==> 3\n"
+"  /eval -n ${base_encode:64,test}                 ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}             ==> test\n"
+"  /eval -n ${translate:Plugin}                    ==> Extension\n"
+"  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/fr.po b/po/fr.po
index 95c729bc7..d943cded8 100644
--- a/po/fr.po
+++ b/po/fr.po
@@ -21,8 +21,8 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2021-09-09 21:07+0200\n"
-"PO-Revision-Date: 2021-09-09 21:13+0200\n"
+"POT-Creation-Date: 2021-09-20 21:12+0200\n"
+"PO-Revision-Date: 2021-09-20 21:13+0200\n"
 "Last-Translator: Sébastien Helleu <flashcode@flashtux.org>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
 "Language: fr\n"
@@ -1713,36 +1713,38 @@ msgid ""
 "Some variables are replaced in expression, using the format ${variable}, "
 "variable can be, by order of priority:\n"
 "  1. the string itself without evaluation (format: \"raw:xxx\")\n"
-"  2. an evaluated sub-string (format: \"eval:xxx\")\n"
-"  3. an evaluated condition (format: \"eval_cond:xxx\")\n"
-"  4. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
-"  5. a string with chars to hide (format: \"hide:char,string\")\n"
-"  6. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
+"  2. a user-defined variable (format: \"name\")\n"
+"  3. an evaluated sub-string (format: \"eval:xxx\")\n"
+"  4. an evaluated condition (format: \"eval_cond:xxx\")\n"
+"  5. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
+"  6. a string with chars to hide (format: \"hide:char,string\")\n"
+"  7. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
 "+max,suffix,string\")\n"
 "     or max chars displayed on screen (format: \"cutscr:max,suffix,string\" "
 "or \"cutscr:+max,suffix,string\")\n"
-"  7. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
-"  8. a repeated string (format: \"repeat:count,string\")\n"
-"  9. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
-"  10. split of a string (format: \"split:number,separators,flags,xxx\")\n"
-"  11. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
-"  12. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
+"  8. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
+"  9. a repeated string (format: \"repeat:count,string\")\n"
+"  10. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
+"  11. split of a string (format: \"split:number,separators,flags,xxx\")\n"
+"  12. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
+"  13. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
 "\"color\")\n"
-"  13. a modifier (format: \"modifier:name,data,string\")\n"
-"  14. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  15. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"  14. a modifier (format: \"modifier:name,data,string\")\n"
+"  15. an info (format: \"info:name,arguments\", arguments are optional)\n"
+"  16. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
 "\" or \"base_decode:base,xxx\")\n"
-"  16. current date/time (format: \"date\" or \"date:format\")\n"
-"  17. an environment variable (format: \"env:XXX\")\n"
-"  18. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  17. current date/time (format: \"date\" or \"date:format\")\n"
+"  18. an environment variable (format: \"env:XXX\")\n"
+"  19. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  19. result of an expression with parentheses and operators + - * / // % ** "
+"  20. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  20. a random integer number (format: \"random:min,max\")\n"
-"  21. a translated string (format: \"translate:xxx\")\n"
-"  22. an option (format: \"file.section.option\")\n"
-"  23. a local variable in buffer\n"
-"  24. a hdata name/variable (the value is automatically converted to "
+"  21. a random integer number (format: \"random:min,max\")\n"
+"  22. a translated string (format: \"translate:xxx\")\n"
+"  23. define a user variable (format: \"define:name,value\")\n"
+"  24. an option (format: \"file.section.option\")\n"
+"  25. a local variable in buffer\n"
+"  26. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1764,38 +1766,39 @@ msgid ""
 "function \"weechat_hdata_get\".\n"
 "\n"
 "Examples (simple strings):\n"
-"  /eval -n ${raw:${info:version}}                ==> ${info:version}\n"
-"  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1\n"
-"  /eval -n ${info:version}                       ==> 0.4.3\n"
-"  /eval -n ${env:HOME}                           ==> /home/user\n"
-"  /eval -n ${weechat.look.scroll_amount}         ==> 3\n"
-"  /eval -n ${sec.data.password}                  ==> secret\n"
-"  /eval -n ${window}                             ==> 0x2549aa0\n"
-"  /eval -n ${window.buffer}                      ==> 0x2549320\n"
-"  /eval -n ${window.buffer.full_name}            ==> core.weechat\n"
-"  /eval -n ${window.buffer.number}               ==> 1\n"
-"  /eval -n ${\\t}                                 ==> <tab>\n"
-"  /eval -n ${hide:-,${relay.network.password}}   ==> --------\n"
-"  /eval -n ${cut:3,+,test}                       ==> tes+\n"
-"  /eval -n ${cut:+3,+,test}                      ==> te+\n"
-"  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40\n"
-"  /eval -n ${if:${info:term_width}>80?big:small} ==> big\n"
-"  /eval -n ${rev:Hello}                          ==> olleH\n"
-"  /eval -n ${repeat:5,-}                         ==> -----\n"
-"  /eval -n ${length:test}                        ==> 4\n"
-"  /eval -n ${split:1,,,abc,def,ghi}              ==> abc\n"
-"  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi\n"
-"  /eval -n ${split:count,,,abc,def,ghi}          ==> 3\n"
-"  /eval -n ${split:random,,,abc,def,ghi}         ==> def\n"
-"  /eval -n ${split_shell:1,\"arg 1\" arg2}         ==> arg 1\n"
-"  /eval -n ${split_shell:-1,\"arg 1\" arg2}        ==> arg2\n"
-"  /eval -n ${split_shell:count,\"arg 1\" arg2}     ==> 2\n"
-"  /eval -n ${split_shell:random,\"arg 1\" arg2}    ==> arg2\n"
-"  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
-"  /eval -n ${random:0,10}                        ==> 3\n"
-"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
-"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
-"  /eval -n ${translate:Plugin}                   ==> Extension\n"
+"  /eval -n ${raw:${info:version}}                 ==> ${info:version}\n"
+"  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1\n"
+"  /eval -n ${info:version}                        ==> 0.4.3\n"
+"  /eval -n ${env:HOME}                            ==> /home/user\n"
+"  /eval -n ${weechat.look.scroll_amount}          ==> 3\n"
+"  /eval -n ${sec.data.password}                   ==> secret\n"
+"  /eval -n ${window}                              ==> 0x2549aa0\n"
+"  /eval -n ${window.buffer}                       ==> 0x2549320\n"
+"  /eval -n ${window.buffer.full_name}             ==> core.weechat\n"
+"  /eval -n ${window.buffer.number}                ==> 1\n"
+"  /eval -n ${\\t}                                  ==> <tab>\n"
+"  /eval -n ${hide:-,${relay.network.password}}    ==> --------\n"
+"  /eval -n ${cut:3,+,test}                        ==> tes+\n"
+"  /eval -n ${cut:+3,+,test}                       ==> te+\n"
+"  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40\n"
+"  /eval -n ${if:${info:term_width}>80?big:small}  ==> big\n"
+"  /eval -n ${rev:Hello}                           ==> olleH\n"
+"  /eval -n ${repeat:5,-}                          ==> -----\n"
+"  /eval -n ${length:test}                         ==> 4\n"
+"  /eval -n ${split:1,,,abc,def,ghi}               ==> abc\n"
+"  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi\n"
+"  /eval -n ${split:count,,,abc,def,ghi}           ==> 3\n"
+"  /eval -n ${split:random,,,abc,def,ghi}          ==> def\n"
+"  /eval -n ${split_shell:1,\"arg 1\" arg2}          ==> arg 1\n"
+"  /eval -n ${split_shell:-1,\"arg 1\" arg2}         ==> arg2\n"
+"  /eval -n ${split_shell:count,\"arg 1\" arg2}      ==> 2\n"
+"  /eval -n ${split_shell:random,\"arg 1\" arg2}     ==> arg2\n"
+"  /eval -n ${calc:(5+2)*3}                        ==> 21\n"
+"  /eval -n ${random:0,10}                         ==> 3\n"
+"  /eval -n ${base_encode:64,test}                 ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}             ==> test\n"
+"  /eval -n ${translate:Plugin}                    ==> Extension\n"
+"  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
@@ -1861,40 +1864,43 @@ msgstr ""
 "Des variables sont remplacées dans l'expression, en utilisant le format "
 "${variable}, la variable pouvant être, par ordre de priorité :\n"
 "  1. la chaîne elle-même sans évaluation (format : \"raw:xxx\")\n"
-"  2. une sous-chaîne évaluée (format : \"eval:xxx\")\n"
-"  3. une condition évaluée (format : \"eval_cond:xxx\")\n"
-"  4. une chaîne avec les caractères échappés (format : \"esc:xxx\" ou \"\\xxx"
+"  2. une variable définie par l'utilisateur (format : \"nom\")\n"
+"  3. une sous-chaîne évaluée (format : \"eval:xxx\")\n"
+"  4. une condition évaluée (format : \"eval_cond:xxx\")\n"
+"  5. une chaîne avec les caractères échappés (format : \"esc:xxx\" ou \"\\xxx"
 "\")\n"
-"  5. une chaîne avec des caractères à cacher (format : \"hide:caractère,"
+"  6. une chaîne avec des caractères à cacher (format : \"hide:caractère,"
 "chaîne\")\n"
-"  6. une chaîne avec un maximum de caractères (format : \"cut:max,suffixe,"
+"  7. une chaîne avec un maximum de caractères (format : \"cut:max,suffixe,"
 "chaîne\" ou \"cut:+max,suffixe,chaîne\")\n"
 "     ou un maximum de caractères affichés à l'écran (format : \"cutscr:max,"
 "suffixe,chaîne\" ou \"cutscr:+max,suffixe,chaîne\")\n"
-"  7. une chaîne inversée (format : \"rev:xxx\" ou \"revscr:xxx\")\n"
-"  8. une chaîne répétée (format : \"repeat:nombre,chaîne\")\n"
-"  9. longueur d'une chaîne (format : \"length:xxx\" ou \"lengthscr:xxx\")\n"
-"  10. découpage d'une chaîne (format : \"split:nombre,séparateurs,flags,xxx"
+"  8. une chaîne inversée (format : \"rev:xxx\" ou \"revscr:xxx\")\n"
+"  9. une chaîne répétée (format : \"repeat:nombre,chaîne\")\n"
+"  10. longueur d'une chaîne (format : \"length:xxx\" ou \"lengthscr:xxx\")\n"
+"  11. découpage d'une chaîne (format : \"split:nombre,séparateurs,flags,xxx"
 "\")\n"
-"  11. découpage de paramètres shell (format : \"split_shell:nombre,xxx\")\n"
-"  12. une couleur (format : \"color:xxx\", voir la \"Référence API extension"
+"  12. découpage de paramètres shell (format : \"split_shell:nombre,xxx\")\n"
+"  13. une couleur (format : \"color:xxx\", voir la \"Référence API extension"
 "\", fonction \"color\")\n"
-"  13. un modificateur (format : \"modifier:nom,données,chaîne\")\n"
-"  14. une info (format : \"info:nom,paramètres\", les paramètres sont "
+"  14. un modificateur (format : \"modifier:nom,données,chaîne\")\n"
+"  15. une info (format : \"info:nom,paramètres\", les paramètres sont "
 "optionnels)\n"
-"  15. une chaîne encodée/decodée en base 16, 32 ou 64 (format : "
+"  16. une chaîne encodée/decodée en base 16, 32 ou 64 (format : "
 "\"base_encode:base,xxx\" ou \"base_decode:base,xxx\")\n"
-"  16. la date/heure courante (format : \"date\" ou \"date:format\")\n"
-"  17. une variable d'environnement (format : \"env:XXX\")\n"
-"  18. un opérateur ternaire (format : \"if:condition?valeur_si_vrai:"
+"  17. la date/heure courante (format : \"date\" ou \"date:format\")\n"
+"  18. une variable d'environnement (format : \"env:XXX\")\n"
+"  19. un opérateur ternaire (format : \"if:condition?valeur_si_vrai:"
 "valeur_si_faux\")\n"
-"  19. le résultat d'une expression avec parenthèses et les opérateurs + - "
-"* / // % ** (format: \"calc:xxx\")\n"
-"  20. un nombre entier aléatoire (format : \"random:min,max\")\n"
-"  21. une chaîne traduite (format : \"translate:xxx\")\n"
-"  22. une option (format : \"fichier.section.option\")\n"
-"  23. une variable locale du tampon\n"
-"  24. un hdata/variable (la valeur est automatiquement convertie en chaîne), "
+"  20. le résultat d'une expression avec parenthèses et les opérateurs + - "
+"* / // % ** (format : \"calc:xxx\")\n"
+"  21. un nombre entier aléatoire (format : \"random:min,max\")\n"
+"  22. une chaîne traduite (format : \"translate:xxx\")\n"
+"  23. déclaration d'une variable utilisateur (format : \"define:nom,valeur"
+"\")\n"
+"  24. une option (format : \"fichier.section.option\")\n"
+"  25. une variable locale du tampon\n"
+"  26. un hdata/variable (la valeur est automatiquement convertie en chaîne), "
 "par défaut \"window\" et \"buffer\" pointent vers la fenêtre et le tampon "
 "courants.\n"
 "Le format du hdata peut être le suivant :\n"
@@ -1917,38 +1923,39 @@ msgstr ""
 "fonction \"weechat_hdata_get\".\n"
 "\n"
 "Exemples (chaînes simples) :\n"
-"  /eval -n ${raw:${info:version}}                ==> ${info:version}\n"
-"  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1\n"
-"  /eval -n ${info:version}                       ==> 0.4.3\n"
-"  /eval -n ${env:HOME}                           ==> /home/user\n"
-"  /eval -n ${weechat.look.scroll_amount}         ==> 3\n"
-"  /eval -n ${sec.data.password}                  ==> secret\n"
-"  /eval -n ${window}                             ==> 0x2549aa0\n"
-"  /eval -n ${window.buffer}                      ==> 0x2549320\n"
-"  /eval -n ${window.buffer.full_name}            ==> core.weechat\n"
-"  /eval -n ${window.buffer.number}               ==> 1\n"
-"  /eval -n ${\\t}                                 ==> <tab>\n"
-"  /eval -n ${hide:-,${relay.network.password}}   ==> --------\n"
-"  /eval -n ${cut:3,+,test}                       ==> tes+\n"
-"  /eval -n ${cut:+3,+,test}                      ==> te+\n"
-"  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40\n"
-"  /eval -n ${if:${info:term_width}>80?big:small} ==> big\n"
-"  /eval -n ${rev:Hello}                          ==> olleH\n"
-"  /eval -n ${repeat:5,-}                         ==> -----\n"
-"  /eval -n ${length:test}                        ==> 4\n"
-"  /eval -n ${split:1,,,abc,def,ghi}              ==> abc\n"
-"  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi\n"
-"  /eval -n ${split:count,,,abc,def,ghi}          ==> 3\n"
-"  /eval -n ${split:random,,,abc,def,ghi}         ==> def\n"
-"  /eval -n ${split_shell:1,\"arg 1\" arg2}         ==> arg 1\n"
-"  /eval -n ${split_shell:-1,\"arg 1\" arg2}        ==> arg2\n"
-"  /eval -n ${split_shell:count,\"arg 1\" arg2}     ==> 2\n"
-"  /eval -n ${split_shell:random,\"arg 1\" arg2}    ==> arg2\n"
-"  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
-"  /eval -n ${random:0,10}                        ==> 3\n"
-"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
-"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
-"  /eval -n ${translate:Plugin}                   ==> Extension\n"
+"  /eval -n ${raw:${info:version}}                 ==> ${info:version}\n"
+"  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1\n"
+"  /eval -n ${info:version}                        ==> 0.4.3\n"
+"  /eval -n ${env:HOME}                            ==> /home/user\n"
+"  /eval -n ${weechat.look.scroll_amount}          ==> 3\n"
+"  /eval -n ${sec.data.password}                   ==> secret\n"
+"  /eval -n ${window}                              ==> 0x2549aa0\n"
+"  /eval -n ${window.buffer}                       ==> 0x2549320\n"
+"  /eval -n ${window.buffer.full_name}             ==> core.weechat\n"
+"  /eval -n ${window.buffer.number}                ==> 1\n"
+"  /eval -n ${\\t}                                  ==> <tab>\n"
+"  /eval -n ${hide:-,${relay.network.password}}    ==> --------\n"
+"  /eval -n ${cut:3,+,test}                        ==> tes+\n"
+"  /eval -n ${cut:+3,+,test}                       ==> te+\n"
+"  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40\n"
+"  /eval -n ${if:${info:term_width}>80?big:small}  ==> big\n"
+"  /eval -n ${rev:Hello}                           ==> olleH\n"
+"  /eval -n ${repeat:5,-}                          ==> -----\n"
+"  /eval -n ${length:test}                         ==> 4\n"
+"  /eval -n ${split:1,,,abc,def,ghi}               ==> abc\n"
+"  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi\n"
+"  /eval -n ${split:count,,,abc,def,ghi}           ==> 3\n"
+"  /eval -n ${split:random,,,abc,def,ghi}          ==> def\n"
+"  /eval -n ${split_shell:1,\"arg 1\" arg2}          ==> arg 1\n"
+"  /eval -n ${split_shell:-1,\"arg 1\" arg2}         ==> arg2\n"
+"  /eval -n ${split_shell:count,\"arg 1\" arg2}      ==> 2\n"
+"  /eval -n ${split_shell:random,\"arg 1\" arg2}     ==> arg2\n"
+"  /eval -n ${calc:(5+2)*3}                        ==> 21\n"
+"  /eval -n ${random:0,10}                         ==> 3\n"
+"  /eval -n ${base_encode:64,test}                 ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}             ==> test\n"
+"  /eval -n ${translate:Plugin}                    ==> Extension\n"
+"  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8\n"
 "\n"
 "Exemples (conditions) :\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/hu.po b/po/hu.po
index 7470d5695..4227a63b9 100644
--- a/po/hu.po
+++ b/po/hu.po
@@ -20,7 +20,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2021-09-09 21:07+0200\n"
+"POT-Creation-Date: 2021-09-20 21:12+0200\n"
 "PO-Revision-Date: 2021-07-10 16:01+0200\n"
 "Last-Translator: Andras Voroskoi <voroskoi@frugalware.org>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -1513,36 +1513,38 @@ msgid ""
 "Some variables are replaced in expression, using the format ${variable}, "
 "variable can be, by order of priority:\n"
 "  1. the string itself without evaluation (format: \"raw:xxx\")\n"
-"  2. an evaluated sub-string (format: \"eval:xxx\")\n"
-"  3. an evaluated condition (format: \"eval_cond:xxx\")\n"
-"  4. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
-"  5. a string with chars to hide (format: \"hide:char,string\")\n"
-"  6. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
+"  2. a user-defined variable (format: \"name\")\n"
+"  3. an evaluated sub-string (format: \"eval:xxx\")\n"
+"  4. an evaluated condition (format: \"eval_cond:xxx\")\n"
+"  5. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
+"  6. a string with chars to hide (format: \"hide:char,string\")\n"
+"  7. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
 "+max,suffix,string\")\n"
 "     or max chars displayed on screen (format: \"cutscr:max,suffix,string\" "
 "or \"cutscr:+max,suffix,string\")\n"
-"  7. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
-"  8. a repeated string (format: \"repeat:count,string\")\n"
-"  9. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
-"  10. split of a string (format: \"split:number,separators,flags,xxx\")\n"
-"  11. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
-"  12. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
+"  8. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
+"  9. a repeated string (format: \"repeat:count,string\")\n"
+"  10. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
+"  11. split of a string (format: \"split:number,separators,flags,xxx\")\n"
+"  12. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
+"  13. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
 "\"color\")\n"
-"  13. a modifier (format: \"modifier:name,data,string\")\n"
-"  14. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  15. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"  14. a modifier (format: \"modifier:name,data,string\")\n"
+"  15. an info (format: \"info:name,arguments\", arguments are optional)\n"
+"  16. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
 "\" or \"base_decode:base,xxx\")\n"
-"  16. current date/time (format: \"date\" or \"date:format\")\n"
-"  17. an environment variable (format: \"env:XXX\")\n"
-"  18. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  17. current date/time (format: \"date\" or \"date:format\")\n"
+"  18. an environment variable (format: \"env:XXX\")\n"
+"  19. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  19. result of an expression with parentheses and operators + - * / // % ** "
+"  20. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  20. a random integer number (format: \"random:min,max\")\n"
-"  21. a translated string (format: \"translate:xxx\")\n"
-"  22. an option (format: \"file.section.option\")\n"
-"  23. a local variable in buffer\n"
-"  24. a hdata name/variable (the value is automatically converted to "
+"  21. a random integer number (format: \"random:min,max\")\n"
+"  22. a translated string (format: \"translate:xxx\")\n"
+"  23. define a user variable (format: \"define:name,value\")\n"
+"  24. an option (format: \"file.section.option\")\n"
+"  25. a local variable in buffer\n"
+"  26. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1564,38 +1566,39 @@ msgid ""
 "function \"weechat_hdata_get\".\n"
 "\n"
 "Examples (simple strings):\n"
-"  /eval -n ${raw:${info:version}}                ==> ${info:version}\n"
-"  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1\n"
-"  /eval -n ${info:version}                       ==> 0.4.3\n"
-"  /eval -n ${env:HOME}                           ==> /home/user\n"
-"  /eval -n ${weechat.look.scroll_amount}         ==> 3\n"
-"  /eval -n ${sec.data.password}                  ==> secret\n"
-"  /eval -n ${window}                             ==> 0x2549aa0\n"
-"  /eval -n ${window.buffer}                      ==> 0x2549320\n"
-"  /eval -n ${window.buffer.full_name}            ==> core.weechat\n"
-"  /eval -n ${window.buffer.number}               ==> 1\n"
-"  /eval -n ${\\t}                                 ==> <tab>\n"
-"  /eval -n ${hide:-,${relay.network.password}}   ==> --------\n"
-"  /eval -n ${cut:3,+,test}                       ==> tes+\n"
-"  /eval -n ${cut:+3,+,test}                      ==> te+\n"
-"  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40\n"
-"  /eval -n ${if:${info:term_width}>80?big:small} ==> big\n"
-"  /eval -n ${rev:Hello}                          ==> olleH\n"
-"  /eval -n ${repeat:5,-}                         ==> -----\n"
-"  /eval -n ${length:test}                        ==> 4\n"
-"  /eval -n ${split:1,,,abc,def,ghi}              ==> abc\n"
-"  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi\n"
-"  /eval -n ${split:count,,,abc,def,ghi}          ==> 3\n"
-"  /eval -n ${split:random,,,abc,def,ghi}         ==> def\n"
-"  /eval -n ${split_shell:1,\"arg 1\" arg2}         ==> arg 1\n"
-"  /eval -n ${split_shell:-1,\"arg 1\" arg2}        ==> arg2\n"
-"  /eval -n ${split_shell:count,\"arg 1\" arg2}     ==> 2\n"
-"  /eval -n ${split_shell:random,\"arg 1\" arg2}    ==> arg2\n"
-"  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
-"  /eval -n ${random:0,10}                        ==> 3\n"
-"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
-"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
-"  /eval -n ${translate:Plugin}                   ==> Extension\n"
+"  /eval -n ${raw:${info:version}}                 ==> ${info:version}\n"
+"  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1\n"
+"  /eval -n ${info:version}                        ==> 0.4.3\n"
+"  /eval -n ${env:HOME}                            ==> /home/user\n"
+"  /eval -n ${weechat.look.scroll_amount}          ==> 3\n"
+"  /eval -n ${sec.data.password}                   ==> secret\n"
+"  /eval -n ${window}                              ==> 0x2549aa0\n"
+"  /eval -n ${window.buffer}                       ==> 0x2549320\n"
+"  /eval -n ${window.buffer.full_name}             ==> core.weechat\n"
+"  /eval -n ${window.buffer.number}                ==> 1\n"
+"  /eval -n ${\\t}                                  ==> <tab>\n"
+"  /eval -n ${hide:-,${relay.network.password}}    ==> --------\n"
+"  /eval -n ${cut:3,+,test}                        ==> tes+\n"
+"  /eval -n ${cut:+3,+,test}                       ==> te+\n"
+"  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40\n"
+"  /eval -n ${if:${info:term_width}>80?big:small}  ==> big\n"
+"  /eval -n ${rev:Hello}                           ==> olleH\n"
+"  /eval -n ${repeat:5,-}                          ==> -----\n"
+"  /eval -n ${length:test}                         ==> 4\n"
+"  /eval -n ${split:1,,,abc,def,ghi}               ==> abc\n"
+"  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi\n"
+"  /eval -n ${split:count,,,abc,def,ghi}           ==> 3\n"
+"  /eval -n ${split:random,,,abc,def,ghi}          ==> def\n"
+"  /eval -n ${split_shell:1,\"arg 1\" arg2}          ==> arg 1\n"
+"  /eval -n ${split_shell:-1,\"arg 1\" arg2}         ==> arg2\n"
+"  /eval -n ${split_shell:count,\"arg 1\" arg2}      ==> 2\n"
+"  /eval -n ${split_shell:random,\"arg 1\" arg2}     ==> arg2\n"
+"  /eval -n ${calc:(5+2)*3}                        ==> 21\n"
+"  /eval -n ${random:0,10}                         ==> 3\n"
+"  /eval -n ${base_encode:64,test}                 ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}             ==> test\n"
+"  /eval -n ${translate:Plugin}                    ==> Extension\n"
+"  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/it.po b/po/it.po
index 4cfbdc4a2..d9ee49c3f 100644
--- a/po/it.po
+++ b/po/it.po
@@ -20,7 +20,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2021-09-09 21:07+0200\n"
+"POT-Creation-Date: 2021-09-20 21:12+0200\n"
 "PO-Revision-Date: 2021-07-10 16:01+0200\n"
 "Last-Translator: Esteban I. Ruiz Moreno <exio4.com@gmail.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -1610,36 +1610,38 @@ msgid ""
 "Some variables are replaced in expression, using the format ${variable}, "
 "variable can be, by order of priority:\n"
 "  1. the string itself without evaluation (format: \"raw:xxx\")\n"
-"  2. an evaluated sub-string (format: \"eval:xxx\")\n"
-"  3. an evaluated condition (format: \"eval_cond:xxx\")\n"
-"  4. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
-"  5. a string with chars to hide (format: \"hide:char,string\")\n"
-"  6. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
+"  2. a user-defined variable (format: \"name\")\n"
+"  3. an evaluated sub-string (format: \"eval:xxx\")\n"
+"  4. an evaluated condition (format: \"eval_cond:xxx\")\n"
+"  5. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
+"  6. a string with chars to hide (format: \"hide:char,string\")\n"
+"  7. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
 "+max,suffix,string\")\n"
 "     or max chars displayed on screen (format: \"cutscr:max,suffix,string\" "
 "or \"cutscr:+max,suffix,string\")\n"
-"  7. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
-"  8. a repeated string (format: \"repeat:count,string\")\n"
-"  9. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
-"  10. split of a string (format: \"split:number,separators,flags,xxx\")\n"
-"  11. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
-"  12. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
+"  8. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
+"  9. a repeated string (format: \"repeat:count,string\")\n"
+"  10. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
+"  11. split of a string (format: \"split:number,separators,flags,xxx\")\n"
+"  12. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
+"  13. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
 "\"color\")\n"
-"  13. a modifier (format: \"modifier:name,data,string\")\n"
-"  14. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  15. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"  14. a modifier (format: \"modifier:name,data,string\")\n"
+"  15. an info (format: \"info:name,arguments\", arguments are optional)\n"
+"  16. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
 "\" or \"base_decode:base,xxx\")\n"
-"  16. current date/time (format: \"date\" or \"date:format\")\n"
-"  17. an environment variable (format: \"env:XXX\")\n"
-"  18. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  17. current date/time (format: \"date\" or \"date:format\")\n"
+"  18. an environment variable (format: \"env:XXX\")\n"
+"  19. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  19. result of an expression with parentheses and operators + - * / // % ** "
+"  20. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  20. a random integer number (format: \"random:min,max\")\n"
-"  21. a translated string (format: \"translate:xxx\")\n"
-"  22. an option (format: \"file.section.option\")\n"
-"  23. a local variable in buffer\n"
-"  24. a hdata name/variable (the value is automatically converted to "
+"  21. a random integer number (format: \"random:min,max\")\n"
+"  22. a translated string (format: \"translate:xxx\")\n"
+"  23. define a user variable (format: \"define:name,value\")\n"
+"  24. an option (format: \"file.section.option\")\n"
+"  25. a local variable in buffer\n"
+"  26. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1661,38 +1663,39 @@ msgid ""
 "function \"weechat_hdata_get\".\n"
 "\n"
 "Examples (simple strings):\n"
-"  /eval -n ${raw:${info:version}}                ==> ${info:version}\n"
-"  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1\n"
-"  /eval -n ${info:version}                       ==> 0.4.3\n"
-"  /eval -n ${env:HOME}                           ==> /home/user\n"
-"  /eval -n ${weechat.look.scroll_amount}         ==> 3\n"
-"  /eval -n ${sec.data.password}                  ==> secret\n"
-"  /eval -n ${window}                             ==> 0x2549aa0\n"
-"  /eval -n ${window.buffer}                      ==> 0x2549320\n"
-"  /eval -n ${window.buffer.full_name}            ==> core.weechat\n"
-"  /eval -n ${window.buffer.number}               ==> 1\n"
-"  /eval -n ${\\t}                                 ==> <tab>\n"
-"  /eval -n ${hide:-,${relay.network.password}}   ==> --------\n"
-"  /eval -n ${cut:3,+,test}                       ==> tes+\n"
-"  /eval -n ${cut:+3,+,test}                      ==> te+\n"
-"  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40\n"
-"  /eval -n ${if:${info:term_width}>80?big:small} ==> big\n"
-"  /eval -n ${rev:Hello}                          ==> olleH\n"
-"  /eval -n ${repeat:5,-}                         ==> -----\n"
-"  /eval -n ${length:test}                        ==> 4\n"
-"  /eval -n ${split:1,,,abc,def,ghi}              ==> abc\n"
-"  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi\n"
-"  /eval -n ${split:count,,,abc,def,ghi}          ==> 3\n"
-"  /eval -n ${split:random,,,abc,def,ghi}         ==> def\n"
-"  /eval -n ${split_shell:1,\"arg 1\" arg2}         ==> arg 1\n"
-"  /eval -n ${split_shell:-1,\"arg 1\" arg2}        ==> arg2\n"
-"  /eval -n ${split_shell:count,\"arg 1\" arg2}     ==> 2\n"
-"  /eval -n ${split_shell:random,\"arg 1\" arg2}    ==> arg2\n"
-"  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
-"  /eval -n ${random:0,10}                        ==> 3\n"
-"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
-"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
-"  /eval -n ${translate:Plugin}                   ==> Extension\n"
+"  /eval -n ${raw:${info:version}}                 ==> ${info:version}\n"
+"  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1\n"
+"  /eval -n ${info:version}                        ==> 0.4.3\n"
+"  /eval -n ${env:HOME}                            ==> /home/user\n"
+"  /eval -n ${weechat.look.scroll_amount}          ==> 3\n"
+"  /eval -n ${sec.data.password}                   ==> secret\n"
+"  /eval -n ${window}                              ==> 0x2549aa0\n"
+"  /eval -n ${window.buffer}                       ==> 0x2549320\n"
+"  /eval -n ${window.buffer.full_name}             ==> core.weechat\n"
+"  /eval -n ${window.buffer.number}                ==> 1\n"
+"  /eval -n ${\\t}                                  ==> <tab>\n"
+"  /eval -n ${hide:-,${relay.network.password}}    ==> --------\n"
+"  /eval -n ${cut:3,+,test}                        ==> tes+\n"
+"  /eval -n ${cut:+3,+,test}                       ==> te+\n"
+"  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40\n"
+"  /eval -n ${if:${info:term_width}>80?big:small}  ==> big\n"
+"  /eval -n ${rev:Hello}                           ==> olleH\n"
+"  /eval -n ${repeat:5,-}                          ==> -----\n"
+"  /eval -n ${length:test}                         ==> 4\n"
+"  /eval -n ${split:1,,,abc,def,ghi}               ==> abc\n"
+"  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi\n"
+"  /eval -n ${split:count,,,abc,def,ghi}           ==> 3\n"
+"  /eval -n ${split:random,,,abc,def,ghi}          ==> def\n"
+"  /eval -n ${split_shell:1,\"arg 1\" arg2}          ==> arg 1\n"
+"  /eval -n ${split_shell:-1,\"arg 1\" arg2}         ==> arg2\n"
+"  /eval -n ${split_shell:count,\"arg 1\" arg2}      ==> 2\n"
+"  /eval -n ${split_shell:random,\"arg 1\" arg2}     ==> arg2\n"
+"  /eval -n ${calc:(5+2)*3}                        ==> 21\n"
+"  /eval -n ${random:0,10}                         ==> 3\n"
+"  /eval -n ${base_encode:64,test}                 ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}             ==> test\n"
+"  /eval -n ${translate:Plugin}                    ==> Extension\n"
+"  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/ja.po b/po/ja.po
index 1fedb02f0..545240771 100644
--- a/po/ja.po
+++ b/po/ja.po
@@ -20,7 +20,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2021-09-09 21:07+0200\n"
+"POT-Creation-Date: 2021-09-20 21:12+0200\n"
 "PO-Revision-Date: 2021-07-10 16:01+0200\n"
 "Last-Translator: AYANOKOUZI, Ryuunosuke <i38w7i3@yahoo.co.jp>\n"
 "Language-Team: Japanese <https://github.com/l/weechat/tree/master/"
@@ -1694,36 +1694,38 @@ msgid ""
 "Some variables are replaced in expression, using the format ${variable}, "
 "variable can be, by order of priority:\n"
 "  1. the string itself without evaluation (format: \"raw:xxx\")\n"
-"  2. an evaluated sub-string (format: \"eval:xxx\")\n"
-"  3. an evaluated condition (format: \"eval_cond:xxx\")\n"
-"  4. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
-"  5. a string with chars to hide (format: \"hide:char,string\")\n"
-"  6. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
+"  2. a user-defined variable (format: \"name\")\n"
+"  3. an evaluated sub-string (format: \"eval:xxx\")\n"
+"  4. an evaluated condition (format: \"eval_cond:xxx\")\n"
+"  5. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
+"  6. a string with chars to hide (format: \"hide:char,string\")\n"
+"  7. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
 "+max,suffix,string\")\n"
 "     or max chars displayed on screen (format: \"cutscr:max,suffix,string\" "
 "or \"cutscr:+max,suffix,string\")\n"
-"  7. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
-"  8. a repeated string (format: \"repeat:count,string\")\n"
-"  9. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
-"  10. split of a string (format: \"split:number,separators,flags,xxx\")\n"
-"  11. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
-"  12. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
+"  8. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
+"  9. a repeated string (format: \"repeat:count,string\")\n"
+"  10. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
+"  11. split of a string (format: \"split:number,separators,flags,xxx\")\n"
+"  12. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
+"  13. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
 "\"color\")\n"
-"  13. a modifier (format: \"modifier:name,data,string\")\n"
-"  14. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  15. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"  14. a modifier (format: \"modifier:name,data,string\")\n"
+"  15. an info (format: \"info:name,arguments\", arguments are optional)\n"
+"  16. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
 "\" or \"base_decode:base,xxx\")\n"
-"  16. current date/time (format: \"date\" or \"date:format\")\n"
-"  17. an environment variable (format: \"env:XXX\")\n"
-"  18. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  17. current date/time (format: \"date\" or \"date:format\")\n"
+"  18. an environment variable (format: \"env:XXX\")\n"
+"  19. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  19. result of an expression with parentheses and operators + - * / // % ** "
+"  20. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  20. a random integer number (format: \"random:min,max\")\n"
-"  21. a translated string (format: \"translate:xxx\")\n"
-"  22. an option (format: \"file.section.option\")\n"
-"  23. a local variable in buffer\n"
-"  24. a hdata name/variable (the value is automatically converted to "
+"  21. a random integer number (format: \"random:min,max\")\n"
+"  22. a translated string (format: \"translate:xxx\")\n"
+"  23. define a user variable (format: \"define:name,value\")\n"
+"  24. an option (format: \"file.section.option\")\n"
+"  25. a local variable in buffer\n"
+"  26. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1745,38 +1747,39 @@ msgid ""
 "function \"weechat_hdata_get\".\n"
 "\n"
 "Examples (simple strings):\n"
-"  /eval -n ${raw:${info:version}}                ==> ${info:version}\n"
-"  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1\n"
-"  /eval -n ${info:version}                       ==> 0.4.3\n"
-"  /eval -n ${env:HOME}                           ==> /home/user\n"
-"  /eval -n ${weechat.look.scroll_amount}         ==> 3\n"
-"  /eval -n ${sec.data.password}                  ==> secret\n"
-"  /eval -n ${window}                             ==> 0x2549aa0\n"
-"  /eval -n ${window.buffer}                      ==> 0x2549320\n"
-"  /eval -n ${window.buffer.full_name}            ==> core.weechat\n"
-"  /eval -n ${window.buffer.number}               ==> 1\n"
-"  /eval -n ${\\t}                                 ==> <tab>\n"
-"  /eval -n ${hide:-,${relay.network.password}}   ==> --------\n"
-"  /eval -n ${cut:3,+,test}                       ==> tes+\n"
-"  /eval -n ${cut:+3,+,test}                      ==> te+\n"
-"  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40\n"
-"  /eval -n ${if:${info:term_width}>80?big:small} ==> big\n"
-"  /eval -n ${rev:Hello}                          ==> olleH\n"
-"  /eval -n ${repeat:5,-}                         ==> -----\n"
-"  /eval -n ${length:test}                        ==> 4\n"
-"  /eval -n ${split:1,,,abc,def,ghi}              ==> abc\n"
-"  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi\n"
-"  /eval -n ${split:count,,,abc,def,ghi}          ==> 3\n"
-"  /eval -n ${split:random,,,abc,def,ghi}         ==> def\n"
-"  /eval -n ${split_shell:1,\"arg 1\" arg2}         ==> arg 1\n"
-"  /eval -n ${split_shell:-1,\"arg 1\" arg2}        ==> arg2\n"
-"  /eval -n ${split_shell:count,\"arg 1\" arg2}     ==> 2\n"
-"  /eval -n ${split_shell:random,\"arg 1\" arg2}    ==> arg2\n"
-"  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
-"  /eval -n ${random:0,10}                        ==> 3\n"
-"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
-"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
-"  /eval -n ${translate:Plugin}                   ==> Extension\n"
+"  /eval -n ${raw:${info:version}}                 ==> ${info:version}\n"
+"  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1\n"
+"  /eval -n ${info:version}                        ==> 0.4.3\n"
+"  /eval -n ${env:HOME}                            ==> /home/user\n"
+"  /eval -n ${weechat.look.scroll_amount}          ==> 3\n"
+"  /eval -n ${sec.data.password}                   ==> secret\n"
+"  /eval -n ${window}                              ==> 0x2549aa0\n"
+"  /eval -n ${window.buffer}                       ==> 0x2549320\n"
+"  /eval -n ${window.buffer.full_name}             ==> core.weechat\n"
+"  /eval -n ${window.buffer.number}                ==> 1\n"
+"  /eval -n ${\\t}                                  ==> <tab>\n"
+"  /eval -n ${hide:-,${relay.network.password}}    ==> --------\n"
+"  /eval -n ${cut:3,+,test}                        ==> tes+\n"
+"  /eval -n ${cut:+3,+,test}                       ==> te+\n"
+"  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40\n"
+"  /eval -n ${if:${info:term_width}>80?big:small}  ==> big\n"
+"  /eval -n ${rev:Hello}                           ==> olleH\n"
+"  /eval -n ${repeat:5,-}                          ==> -----\n"
+"  /eval -n ${length:test}                         ==> 4\n"
+"  /eval -n ${split:1,,,abc,def,ghi}               ==> abc\n"
+"  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi\n"
+"  /eval -n ${split:count,,,abc,def,ghi}           ==> 3\n"
+"  /eval -n ${split:random,,,abc,def,ghi}          ==> def\n"
+"  /eval -n ${split_shell:1,\"arg 1\" arg2}          ==> arg 1\n"
+"  /eval -n ${split_shell:-1,\"arg 1\" arg2}         ==> arg2\n"
+"  /eval -n ${split_shell:count,\"arg 1\" arg2}      ==> 2\n"
+"  /eval -n ${split_shell:random,\"arg 1\" arg2}     ==> arg2\n"
+"  /eval -n ${calc:(5+2)*3}                        ==> 21\n"
+"  /eval -n ${random:0,10}                         ==> 3\n"
+"  /eval -n ${base_encode:64,test}                 ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}             ==> test\n"
+"  /eval -n ${translate:Plugin}                    ==> Extension\n"
+"  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/pl.po b/po/pl.po
index ffdada94f..e1a961fd6 100644
--- a/po/pl.po
+++ b/po/pl.po
@@ -22,7 +22,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2021-09-09 21:07+0200\n"
+"POT-Creation-Date: 2021-09-20 21:12+0200\n"
 "PO-Revision-Date: 2021-07-10 16:01+0200\n"
 "Last-Translator: Krzysztof Korościk <soltys@soltys.info>\n"
 "Language-Team: Polish <kde-i18n-doc@kde.org>\n"
@@ -1844,36 +1844,38 @@ msgid ""
 "Some variables are replaced in expression, using the format ${variable}, "
 "variable can be, by order of priority:\n"
 "  1. the string itself without evaluation (format: \"raw:xxx\")\n"
-"  2. an evaluated sub-string (format: \"eval:xxx\")\n"
-"  3. an evaluated condition (format: \"eval_cond:xxx\")\n"
-"  4. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
-"  5. a string with chars to hide (format: \"hide:char,string\")\n"
-"  6. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
+"  2. a user-defined variable (format: \"name\")\n"
+"  3. an evaluated sub-string (format: \"eval:xxx\")\n"
+"  4. an evaluated condition (format: \"eval_cond:xxx\")\n"
+"  5. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
+"  6. a string with chars to hide (format: \"hide:char,string\")\n"
+"  7. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
 "+max,suffix,string\")\n"
 "     or max chars displayed on screen (format: \"cutscr:max,suffix,string\" "
 "or \"cutscr:+max,suffix,string\")\n"
-"  7. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
-"  8. a repeated string (format: \"repeat:count,string\")\n"
-"  9. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
-"  10. split of a string (format: \"split:number,separators,flags,xxx\")\n"
-"  11. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
-"  12. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
+"  8. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
+"  9. a repeated string (format: \"repeat:count,string\")\n"
+"  10. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
+"  11. split of a string (format: \"split:number,separators,flags,xxx\")\n"
+"  12. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
+"  13. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
 "\"color\")\n"
-"  13. a modifier (format: \"modifier:name,data,string\")\n"
-"  14. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  15. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"  14. a modifier (format: \"modifier:name,data,string\")\n"
+"  15. an info (format: \"info:name,arguments\", arguments are optional)\n"
+"  16. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
 "\" or \"base_decode:base,xxx\")\n"
-"  16. current date/time (format: \"date\" or \"date:format\")\n"
-"  17. an environment variable (format: \"env:XXX\")\n"
-"  18. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  17. current date/time (format: \"date\" or \"date:format\")\n"
+"  18. an environment variable (format: \"env:XXX\")\n"
+"  19. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  19. result of an expression with parentheses and operators + - * / // % ** "
+"  20. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  20. a random integer number (format: \"random:min,max\")\n"
-"  21. a translated string (format: \"translate:xxx\")\n"
-"  22. an option (format: \"file.section.option\")\n"
-"  23. a local variable in buffer\n"
-"  24. a hdata name/variable (the value is automatically converted to "
+"  21. a random integer number (format: \"random:min,max\")\n"
+"  22. a translated string (format: \"translate:xxx\")\n"
+"  23. define a user variable (format: \"define:name,value\")\n"
+"  24. an option (format: \"file.section.option\")\n"
+"  25. a local variable in buffer\n"
+"  26. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1895,38 +1897,39 @@ msgid ""
 "function \"weechat_hdata_get\".\n"
 "\n"
 "Examples (simple strings):\n"
-"  /eval -n ${raw:${info:version}}                ==> ${info:version}\n"
-"  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1\n"
-"  /eval -n ${info:version}                       ==> 0.4.3\n"
-"  /eval -n ${env:HOME}                           ==> /home/user\n"
-"  /eval -n ${weechat.look.scroll_amount}         ==> 3\n"
-"  /eval -n ${sec.data.password}                  ==> secret\n"
-"  /eval -n ${window}                             ==> 0x2549aa0\n"
-"  /eval -n ${window.buffer}                      ==> 0x2549320\n"
-"  /eval -n ${window.buffer.full_name}            ==> core.weechat\n"
-"  /eval -n ${window.buffer.number}               ==> 1\n"
-"  /eval -n ${\\t}                                 ==> <tab>\n"
-"  /eval -n ${hide:-,${relay.network.password}}   ==> --------\n"
-"  /eval -n ${cut:3,+,test}                       ==> tes+\n"
-"  /eval -n ${cut:+3,+,test}                      ==> te+\n"
-"  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40\n"
-"  /eval -n ${if:${info:term_width}>80?big:small} ==> big\n"
-"  /eval -n ${rev:Hello}                          ==> olleH\n"
-"  /eval -n ${repeat:5,-}                         ==> -----\n"
-"  /eval -n ${length:test}                        ==> 4\n"
-"  /eval -n ${split:1,,,abc,def,ghi}              ==> abc\n"
-"  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi\n"
-"  /eval -n ${split:count,,,abc,def,ghi}          ==> 3\n"
-"  /eval -n ${split:random,,,abc,def,ghi}         ==> def\n"
-"  /eval -n ${split_shell:1,\"arg 1\" arg2}         ==> arg 1\n"
-"  /eval -n ${split_shell:-1,\"arg 1\" arg2}        ==> arg2\n"
-"  /eval -n ${split_shell:count,\"arg 1\" arg2}     ==> 2\n"
-"  /eval -n ${split_shell:random,\"arg 1\" arg2}    ==> arg2\n"
-"  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
-"  /eval -n ${random:0,10}                        ==> 3\n"
-"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
-"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
-"  /eval -n ${translate:Plugin}                   ==> Extension\n"
+"  /eval -n ${raw:${info:version}}                 ==> ${info:version}\n"
+"  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1\n"
+"  /eval -n ${info:version}                        ==> 0.4.3\n"
+"  /eval -n ${env:HOME}                            ==> /home/user\n"
+"  /eval -n ${weechat.look.scroll_amount}          ==> 3\n"
+"  /eval -n ${sec.data.password}                   ==> secret\n"
+"  /eval -n ${window}                              ==> 0x2549aa0\n"
+"  /eval -n ${window.buffer}                       ==> 0x2549320\n"
+"  /eval -n ${window.buffer.full_name}             ==> core.weechat\n"
+"  /eval -n ${window.buffer.number}                ==> 1\n"
+"  /eval -n ${\\t}                                  ==> <tab>\n"
+"  /eval -n ${hide:-,${relay.network.password}}    ==> --------\n"
+"  /eval -n ${cut:3,+,test}                        ==> tes+\n"
+"  /eval -n ${cut:+3,+,test}                       ==> te+\n"
+"  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40\n"
+"  /eval -n ${if:${info:term_width}>80?big:small}  ==> big\n"
+"  /eval -n ${rev:Hello}                           ==> olleH\n"
+"  /eval -n ${repeat:5,-}                          ==> -----\n"
+"  /eval -n ${length:test}                         ==> 4\n"
+"  /eval -n ${split:1,,,abc,def,ghi}               ==> abc\n"
+"  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi\n"
+"  /eval -n ${split:count,,,abc,def,ghi}           ==> 3\n"
+"  /eval -n ${split:random,,,abc,def,ghi}          ==> def\n"
+"  /eval -n ${split_shell:1,\"arg 1\" arg2}          ==> arg 1\n"
+"  /eval -n ${split_shell:-1,\"arg 1\" arg2}         ==> arg2\n"
+"  /eval -n ${split_shell:count,\"arg 1\" arg2}      ==> 2\n"
+"  /eval -n ${split_shell:random,\"arg 1\" arg2}     ==> arg2\n"
+"  /eval -n ${calc:(5+2)*3}                        ==> 21\n"
+"  /eval -n ${random:0,10}                         ==> 3\n"
+"  /eval -n ${base_encode:64,test}                 ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}             ==> test\n"
+"  /eval -n ${translate:Plugin}                    ==> Extension\n"
+"  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/pt.po b/po/pt.po
index 0f93607b3..1806f9f3f 100644
--- a/po/pt.po
+++ b/po/pt.po
@@ -20,7 +20,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2021-09-09 21:07+0200\n"
+"POT-Creation-Date: 2021-09-20 21:12+0200\n"
 "PO-Revision-Date: 2021-07-10 16:01+0200\n"
 "Last-Translator: Vasco Almeida <vascomalmeida@sapo.pt>\n"
 "Language-Team: Portuguese <>\n"
@@ -1698,36 +1698,38 @@ msgid ""
 "Some variables are replaced in expression, using the format ${variable}, "
 "variable can be, by order of priority:\n"
 "  1. the string itself without evaluation (format: \"raw:xxx\")\n"
-"  2. an evaluated sub-string (format: \"eval:xxx\")\n"
-"  3. an evaluated condition (format: \"eval_cond:xxx\")\n"
-"  4. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
-"  5. a string with chars to hide (format: \"hide:char,string\")\n"
-"  6. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
+"  2. a user-defined variable (format: \"name\")\n"
+"  3. an evaluated sub-string (format: \"eval:xxx\")\n"
+"  4. an evaluated condition (format: \"eval_cond:xxx\")\n"
+"  5. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
+"  6. a string with chars to hide (format: \"hide:char,string\")\n"
+"  7. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
 "+max,suffix,string\")\n"
 "     or max chars displayed on screen (format: \"cutscr:max,suffix,string\" "
 "or \"cutscr:+max,suffix,string\")\n"
-"  7. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
-"  8. a repeated string (format: \"repeat:count,string\")\n"
-"  9. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
-"  10. split of a string (format: \"split:number,separators,flags,xxx\")\n"
-"  11. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
-"  12. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
+"  8. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
+"  9. a repeated string (format: \"repeat:count,string\")\n"
+"  10. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
+"  11. split of a string (format: \"split:number,separators,flags,xxx\")\n"
+"  12. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
+"  13. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
 "\"color\")\n"
-"  13. a modifier (format: \"modifier:name,data,string\")\n"
-"  14. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  15. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"  14. a modifier (format: \"modifier:name,data,string\")\n"
+"  15. an info (format: \"info:name,arguments\", arguments are optional)\n"
+"  16. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
 "\" or \"base_decode:base,xxx\")\n"
-"  16. current date/time (format: \"date\" or \"date:format\")\n"
-"  17. an environment variable (format: \"env:XXX\")\n"
-"  18. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  17. current date/time (format: \"date\" or \"date:format\")\n"
+"  18. an environment variable (format: \"env:XXX\")\n"
+"  19. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  19. result of an expression with parentheses and operators + - * / // % ** "
+"  20. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  20. a random integer number (format: \"random:min,max\")\n"
-"  21. a translated string (format: \"translate:xxx\")\n"
-"  22. an option (format: \"file.section.option\")\n"
-"  23. a local variable in buffer\n"
-"  24. a hdata name/variable (the value is automatically converted to "
+"  21. a random integer number (format: \"random:min,max\")\n"
+"  22. a translated string (format: \"translate:xxx\")\n"
+"  23. define a user variable (format: \"define:name,value\")\n"
+"  24. an option (format: \"file.section.option\")\n"
+"  25. a local variable in buffer\n"
+"  26. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1749,38 +1751,39 @@ msgid ""
 "function \"weechat_hdata_get\".\n"
 "\n"
 "Examples (simple strings):\n"
-"  /eval -n ${raw:${info:version}}                ==> ${info:version}\n"
-"  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1\n"
-"  /eval -n ${info:version}                       ==> 0.4.3\n"
-"  /eval -n ${env:HOME}                           ==> /home/user\n"
-"  /eval -n ${weechat.look.scroll_amount}         ==> 3\n"
-"  /eval -n ${sec.data.password}                  ==> secret\n"
-"  /eval -n ${window}                             ==> 0x2549aa0\n"
-"  /eval -n ${window.buffer}                      ==> 0x2549320\n"
-"  /eval -n ${window.buffer.full_name}            ==> core.weechat\n"
-"  /eval -n ${window.buffer.number}               ==> 1\n"
-"  /eval -n ${\\t}                                 ==> <tab>\n"
-"  /eval -n ${hide:-,${relay.network.password}}   ==> --------\n"
-"  /eval -n ${cut:3,+,test}                       ==> tes+\n"
-"  /eval -n ${cut:+3,+,test}                      ==> te+\n"
-"  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40\n"
-"  /eval -n ${if:${info:term_width}>80?big:small} ==> big\n"
-"  /eval -n ${rev:Hello}                          ==> olleH\n"
-"  /eval -n ${repeat:5,-}                         ==> -----\n"
-"  /eval -n ${length:test}                        ==> 4\n"
-"  /eval -n ${split:1,,,abc,def,ghi}              ==> abc\n"
-"  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi\n"
-"  /eval -n ${split:count,,,abc,def,ghi}          ==> 3\n"
-"  /eval -n ${split:random,,,abc,def,ghi}         ==> def\n"
-"  /eval -n ${split_shell:1,\"arg 1\" arg2}         ==> arg 1\n"
-"  /eval -n ${split_shell:-1,\"arg 1\" arg2}        ==> arg2\n"
-"  /eval -n ${split_shell:count,\"arg 1\" arg2}     ==> 2\n"
-"  /eval -n ${split_shell:random,\"arg 1\" arg2}    ==> arg2\n"
-"  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
-"  /eval -n ${random:0,10}                        ==> 3\n"
-"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
-"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
-"  /eval -n ${translate:Plugin}                   ==> Extension\n"
+"  /eval -n ${raw:${info:version}}                 ==> ${info:version}\n"
+"  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1\n"
+"  /eval -n ${info:version}                        ==> 0.4.3\n"
+"  /eval -n ${env:HOME}                            ==> /home/user\n"
+"  /eval -n ${weechat.look.scroll_amount}          ==> 3\n"
+"  /eval -n ${sec.data.password}                   ==> secret\n"
+"  /eval -n ${window}                              ==> 0x2549aa0\n"
+"  /eval -n ${window.buffer}                       ==> 0x2549320\n"
+"  /eval -n ${window.buffer.full_name}             ==> core.weechat\n"
+"  /eval -n ${window.buffer.number}                ==> 1\n"
+"  /eval -n ${\\t}                                  ==> <tab>\n"
+"  /eval -n ${hide:-,${relay.network.password}}    ==> --------\n"
+"  /eval -n ${cut:3,+,test}                        ==> tes+\n"
+"  /eval -n ${cut:+3,+,test}                       ==> te+\n"
+"  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40\n"
+"  /eval -n ${if:${info:term_width}>80?big:small}  ==> big\n"
+"  /eval -n ${rev:Hello}                           ==> olleH\n"
+"  /eval -n ${repeat:5,-}                          ==> -----\n"
+"  /eval -n ${length:test}                         ==> 4\n"
+"  /eval -n ${split:1,,,abc,def,ghi}               ==> abc\n"
+"  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi\n"
+"  /eval -n ${split:count,,,abc,def,ghi}           ==> 3\n"
+"  /eval -n ${split:random,,,abc,def,ghi}          ==> def\n"
+"  /eval -n ${split_shell:1,\"arg 1\" arg2}          ==> arg 1\n"
+"  /eval -n ${split_shell:-1,\"arg 1\" arg2}         ==> arg2\n"
+"  /eval -n ${split_shell:count,\"arg 1\" arg2}      ==> 2\n"
+"  /eval -n ${split_shell:random,\"arg 1\" arg2}     ==> arg2\n"
+"  /eval -n ${calc:(5+2)*3}                        ==> 21\n"
+"  /eval -n ${random:0,10}                         ==> 3\n"
+"  /eval -n ${base_encode:64,test}                 ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}             ==> test\n"
+"  /eval -n ${translate:Plugin}                    ==> Extension\n"
+"  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/pt_BR.po b/po/pt_BR.po
index 140cd0d64..7d3e706fd 100644
--- a/po/pt_BR.po
+++ b/po/pt_BR.po
@@ -21,7 +21,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2021-09-09 21:07+0200\n"
+"POT-Creation-Date: 2021-09-20 21:12+0200\n"
 "PO-Revision-Date: 2021-07-10 16:01+0200\n"
 "Last-Translator: Érico Nogueira <ericonr@disroot.org>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -1673,36 +1673,38 @@ msgid ""
 "Some variables are replaced in expression, using the format ${variable}, "
 "variable can be, by order of priority:\n"
 "  1. the string itself without evaluation (format: \"raw:xxx\")\n"
-"  2. an evaluated sub-string (format: \"eval:xxx\")\n"
-"  3. an evaluated condition (format: \"eval_cond:xxx\")\n"
-"  4. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
-"  5. a string with chars to hide (format: \"hide:char,string\")\n"
-"  6. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
+"  2. a user-defined variable (format: \"name\")\n"
+"  3. an evaluated sub-string (format: \"eval:xxx\")\n"
+"  4. an evaluated condition (format: \"eval_cond:xxx\")\n"
+"  5. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
+"  6. a string with chars to hide (format: \"hide:char,string\")\n"
+"  7. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
 "+max,suffix,string\")\n"
 "     or max chars displayed on screen (format: \"cutscr:max,suffix,string\" "
 "or \"cutscr:+max,suffix,string\")\n"
-"  7. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
-"  8. a repeated string (format: \"repeat:count,string\")\n"
-"  9. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
-"  10. split of a string (format: \"split:number,separators,flags,xxx\")\n"
-"  11. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
-"  12. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
+"  8. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
+"  9. a repeated string (format: \"repeat:count,string\")\n"
+"  10. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
+"  11. split of a string (format: \"split:number,separators,flags,xxx\")\n"
+"  12. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
+"  13. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
 "\"color\")\n"
-"  13. a modifier (format: \"modifier:name,data,string\")\n"
-"  14. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  15. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"  14. a modifier (format: \"modifier:name,data,string\")\n"
+"  15. an info (format: \"info:name,arguments\", arguments are optional)\n"
+"  16. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
 "\" or \"base_decode:base,xxx\")\n"
-"  16. current date/time (format: \"date\" or \"date:format\")\n"
-"  17. an environment variable (format: \"env:XXX\")\n"
-"  18. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  17. current date/time (format: \"date\" or \"date:format\")\n"
+"  18. an environment variable (format: \"env:XXX\")\n"
+"  19. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  19. result of an expression with parentheses and operators + - * / // % ** "
+"  20. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  20. a random integer number (format: \"random:min,max\")\n"
-"  21. a translated string (format: \"translate:xxx\")\n"
-"  22. an option (format: \"file.section.option\")\n"
-"  23. a local variable in buffer\n"
-"  24. a hdata name/variable (the value is automatically converted to "
+"  21. a random integer number (format: \"random:min,max\")\n"
+"  22. a translated string (format: \"translate:xxx\")\n"
+"  23. define a user variable (format: \"define:name,value\")\n"
+"  24. an option (format: \"file.section.option\")\n"
+"  25. a local variable in buffer\n"
+"  26. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1724,38 +1726,39 @@ msgid ""
 "function \"weechat_hdata_get\".\n"
 "\n"
 "Examples (simple strings):\n"
-"  /eval -n ${raw:${info:version}}                ==> ${info:version}\n"
-"  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1\n"
-"  /eval -n ${info:version}                       ==> 0.4.3\n"
-"  /eval -n ${env:HOME}                           ==> /home/user\n"
-"  /eval -n ${weechat.look.scroll_amount}         ==> 3\n"
-"  /eval -n ${sec.data.password}                  ==> secret\n"
-"  /eval -n ${window}                             ==> 0x2549aa0\n"
-"  /eval -n ${window.buffer}                      ==> 0x2549320\n"
-"  /eval -n ${window.buffer.full_name}            ==> core.weechat\n"
-"  /eval -n ${window.buffer.number}               ==> 1\n"
-"  /eval -n ${\\t}                                 ==> <tab>\n"
-"  /eval -n ${hide:-,${relay.network.password}}   ==> --------\n"
-"  /eval -n ${cut:3,+,test}                       ==> tes+\n"
-"  /eval -n ${cut:+3,+,test}                      ==> te+\n"
-"  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40\n"
-"  /eval -n ${if:${info:term_width}>80?big:small} ==> big\n"
-"  /eval -n ${rev:Hello}                          ==> olleH\n"
-"  /eval -n ${repeat:5,-}                         ==> -----\n"
-"  /eval -n ${length:test}                        ==> 4\n"
-"  /eval -n ${split:1,,,abc,def,ghi}              ==> abc\n"
-"  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi\n"
-"  /eval -n ${split:count,,,abc,def,ghi}          ==> 3\n"
-"  /eval -n ${split:random,,,abc,def,ghi}         ==> def\n"
-"  /eval -n ${split_shell:1,\"arg 1\" arg2}         ==> arg 1\n"
-"  /eval -n ${split_shell:-1,\"arg 1\" arg2}        ==> arg2\n"
-"  /eval -n ${split_shell:count,\"arg 1\" arg2}     ==> 2\n"
-"  /eval -n ${split_shell:random,\"arg 1\" arg2}    ==> arg2\n"
-"  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
-"  /eval -n ${random:0,10}                        ==> 3\n"
-"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
-"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
-"  /eval -n ${translate:Plugin}                   ==> Extension\n"
+"  /eval -n ${raw:${info:version}}                 ==> ${info:version}\n"
+"  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1\n"
+"  /eval -n ${info:version}                        ==> 0.4.3\n"
+"  /eval -n ${env:HOME}                            ==> /home/user\n"
+"  /eval -n ${weechat.look.scroll_amount}          ==> 3\n"
+"  /eval -n ${sec.data.password}                   ==> secret\n"
+"  /eval -n ${window}                              ==> 0x2549aa0\n"
+"  /eval -n ${window.buffer}                       ==> 0x2549320\n"
+"  /eval -n ${window.buffer.full_name}             ==> core.weechat\n"
+"  /eval -n ${window.buffer.number}                ==> 1\n"
+"  /eval -n ${\\t}                                  ==> <tab>\n"
+"  /eval -n ${hide:-,${relay.network.password}}    ==> --------\n"
+"  /eval -n ${cut:3,+,test}                        ==> tes+\n"
+"  /eval -n ${cut:+3,+,test}                       ==> te+\n"
+"  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40\n"
+"  /eval -n ${if:${info:term_width}>80?big:small}  ==> big\n"
+"  /eval -n ${rev:Hello}                           ==> olleH\n"
+"  /eval -n ${repeat:5,-}                          ==> -----\n"
+"  /eval -n ${length:test}                         ==> 4\n"
+"  /eval -n ${split:1,,,abc,def,ghi}               ==> abc\n"
+"  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi\n"
+"  /eval -n ${split:count,,,abc,def,ghi}           ==> 3\n"
+"  /eval -n ${split:random,,,abc,def,ghi}          ==> def\n"
+"  /eval -n ${split_shell:1,\"arg 1\" arg2}          ==> arg 1\n"
+"  /eval -n ${split_shell:-1,\"arg 1\" arg2}         ==> arg2\n"
+"  /eval -n ${split_shell:count,\"arg 1\" arg2}      ==> 2\n"
+"  /eval -n ${split_shell:random,\"arg 1\" arg2}     ==> arg2\n"
+"  /eval -n ${calc:(5+2)*3}                        ==> 21\n"
+"  /eval -n ${random:0,10}                         ==> 3\n"
+"  /eval -n ${base_encode:64,test}                 ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}             ==> test\n"
+"  /eval -n ${translate:Plugin}                    ==> Extension\n"
+"  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/ru.po b/po/ru.po
index 550c63e26..4319365be 100644
--- a/po/ru.po
+++ b/po/ru.po
@@ -21,7 +21,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2021-09-09 21:07+0200\n"
+"POT-Creation-Date: 2021-09-20 21:12+0200\n"
 "PO-Revision-Date: 2021-07-10 16:01+0200\n"
 "Last-Translator: Aleksey V Zapparov AKA ixti <ixti@member.fsf.org>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -1536,36 +1536,38 @@ msgid ""
 "Some variables are replaced in expression, using the format ${variable}, "
 "variable can be, by order of priority:\n"
 "  1. the string itself without evaluation (format: \"raw:xxx\")\n"
-"  2. an evaluated sub-string (format: \"eval:xxx\")\n"
-"  3. an evaluated condition (format: \"eval_cond:xxx\")\n"
-"  4. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
-"  5. a string with chars to hide (format: \"hide:char,string\")\n"
-"  6. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
+"  2. a user-defined variable (format: \"name\")\n"
+"  3. an evaluated sub-string (format: \"eval:xxx\")\n"
+"  4. an evaluated condition (format: \"eval_cond:xxx\")\n"
+"  5. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
+"  6. a string with chars to hide (format: \"hide:char,string\")\n"
+"  7. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
 "+max,suffix,string\")\n"
 "     or max chars displayed on screen (format: \"cutscr:max,suffix,string\" "
 "or \"cutscr:+max,suffix,string\")\n"
-"  7. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
-"  8. a repeated string (format: \"repeat:count,string\")\n"
-"  9. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
-"  10. split of a string (format: \"split:number,separators,flags,xxx\")\n"
-"  11. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
-"  12. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
+"  8. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
+"  9. a repeated string (format: \"repeat:count,string\")\n"
+"  10. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
+"  11. split of a string (format: \"split:number,separators,flags,xxx\")\n"
+"  12. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
+"  13. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
 "\"color\")\n"
-"  13. a modifier (format: \"modifier:name,data,string\")\n"
-"  14. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  15. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"  14. a modifier (format: \"modifier:name,data,string\")\n"
+"  15. an info (format: \"info:name,arguments\", arguments are optional)\n"
+"  16. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
 "\" or \"base_decode:base,xxx\")\n"
-"  16. current date/time (format: \"date\" or \"date:format\")\n"
-"  17. an environment variable (format: \"env:XXX\")\n"
-"  18. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  17. current date/time (format: \"date\" or \"date:format\")\n"
+"  18. an environment variable (format: \"env:XXX\")\n"
+"  19. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  19. result of an expression with parentheses and operators + - * / // % ** "
+"  20. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  20. a random integer number (format: \"random:min,max\")\n"
-"  21. a translated string (format: \"translate:xxx\")\n"
-"  22. an option (format: \"file.section.option\")\n"
-"  23. a local variable in buffer\n"
-"  24. a hdata name/variable (the value is automatically converted to "
+"  21. a random integer number (format: \"random:min,max\")\n"
+"  22. a translated string (format: \"translate:xxx\")\n"
+"  23. define a user variable (format: \"define:name,value\")\n"
+"  24. an option (format: \"file.section.option\")\n"
+"  25. a local variable in buffer\n"
+"  26. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1587,38 +1589,39 @@ msgid ""
 "function \"weechat_hdata_get\".\n"
 "\n"
 "Examples (simple strings):\n"
-"  /eval -n ${raw:${info:version}}                ==> ${info:version}\n"
-"  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1\n"
-"  /eval -n ${info:version}                       ==> 0.4.3\n"
-"  /eval -n ${env:HOME}                           ==> /home/user\n"
-"  /eval -n ${weechat.look.scroll_amount}         ==> 3\n"
-"  /eval -n ${sec.data.password}                  ==> secret\n"
-"  /eval -n ${window}                             ==> 0x2549aa0\n"
-"  /eval -n ${window.buffer}                      ==> 0x2549320\n"
-"  /eval -n ${window.buffer.full_name}            ==> core.weechat\n"
-"  /eval -n ${window.buffer.number}               ==> 1\n"
-"  /eval -n ${\\t}                                 ==> <tab>\n"
-"  /eval -n ${hide:-,${relay.network.password}}   ==> --------\n"
-"  /eval -n ${cut:3,+,test}                       ==> tes+\n"
-"  /eval -n ${cut:+3,+,test}                      ==> te+\n"
-"  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40\n"
-"  /eval -n ${if:${info:term_width}>80?big:small} ==> big\n"
-"  /eval -n ${rev:Hello}                          ==> olleH\n"
-"  /eval -n ${repeat:5,-}                         ==> -----\n"
-"  /eval -n ${length:test}                        ==> 4\n"
-"  /eval -n ${split:1,,,abc,def,ghi}              ==> abc\n"
-"  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi\n"
-"  /eval -n ${split:count,,,abc,def,ghi}          ==> 3\n"
-"  /eval -n ${split:random,,,abc,def,ghi}         ==> def\n"
-"  /eval -n ${split_shell:1,\"arg 1\" arg2}         ==> arg 1\n"
-"  /eval -n ${split_shell:-1,\"arg 1\" arg2}        ==> arg2\n"
-"  /eval -n ${split_shell:count,\"arg 1\" arg2}     ==> 2\n"
-"  /eval -n ${split_shell:random,\"arg 1\" arg2}    ==> arg2\n"
-"  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
-"  /eval -n ${random:0,10}                        ==> 3\n"
-"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
-"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
-"  /eval -n ${translate:Plugin}                   ==> Extension\n"
+"  /eval -n ${raw:${info:version}}                 ==> ${info:version}\n"
+"  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1\n"
+"  /eval -n ${info:version}                        ==> 0.4.3\n"
+"  /eval -n ${env:HOME}                            ==> /home/user\n"
+"  /eval -n ${weechat.look.scroll_amount}          ==> 3\n"
+"  /eval -n ${sec.data.password}                   ==> secret\n"
+"  /eval -n ${window}                              ==> 0x2549aa0\n"
+"  /eval -n ${window.buffer}                       ==> 0x2549320\n"
+"  /eval -n ${window.buffer.full_name}             ==> core.weechat\n"
+"  /eval -n ${window.buffer.number}                ==> 1\n"
+"  /eval -n ${\\t}                                  ==> <tab>\n"
+"  /eval -n ${hide:-,${relay.network.password}}    ==> --------\n"
+"  /eval -n ${cut:3,+,test}                        ==> tes+\n"
+"  /eval -n ${cut:+3,+,test}                       ==> te+\n"
+"  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40\n"
+"  /eval -n ${if:${info:term_width}>80?big:small}  ==> big\n"
+"  /eval -n ${rev:Hello}                           ==> olleH\n"
+"  /eval -n ${repeat:5,-}                          ==> -----\n"
+"  /eval -n ${length:test}                         ==> 4\n"
+"  /eval -n ${split:1,,,abc,def,ghi}               ==> abc\n"
+"  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi\n"
+"  /eval -n ${split:count,,,abc,def,ghi}           ==> 3\n"
+"  /eval -n ${split:random,,,abc,def,ghi}          ==> def\n"
+"  /eval -n ${split_shell:1,\"arg 1\" arg2}          ==> arg 1\n"
+"  /eval -n ${split_shell:-1,\"arg 1\" arg2}         ==> arg2\n"
+"  /eval -n ${split_shell:count,\"arg 1\" arg2}      ==> 2\n"
+"  /eval -n ${split_shell:random,\"arg 1\" arg2}     ==> arg2\n"
+"  /eval -n ${calc:(5+2)*3}                        ==> 21\n"
+"  /eval -n ${random:0,10}                         ==> 3\n"
+"  /eval -n ${base_encode:64,test}                 ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}             ==> test\n"
+"  /eval -n ${translate:Plugin}                    ==> Extension\n"
+"  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/sr.po b/po/sr.po
index 04e9e172c..dce60e84a 100644
--- a/po/sr.po
+++ b/po/sr.po
@@ -20,7 +20,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2021-09-09 21:07+0200\n"
+"POT-Creation-Date: 2021-09-20 21:12+0200\n"
 "PO-Revision-Date: 2021-09-01 02:38+0400\n"
 "Last-Translator: Ivan Pešić <ivan.pesic@gmail.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -1831,36 +1831,38 @@ msgid ""
 "Some variables are replaced in expression, using the format ${variable}, "
 "variable can be, by order of priority:\n"
 "  1. the string itself without evaluation (format: \"raw:xxx\")\n"
-"  2. an evaluated sub-string (format: \"eval:xxx\")\n"
-"  3. an evaluated condition (format: \"eval_cond:xxx\")\n"
-"  4. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
-"  5. a string with chars to hide (format: \"hide:char,string\")\n"
-"  6. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
+"  2. a user-defined variable (format: \"name\")\n"
+"  3. an evaluated sub-string (format: \"eval:xxx\")\n"
+"  4. an evaluated condition (format: \"eval_cond:xxx\")\n"
+"  5. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
+"  6. a string with chars to hide (format: \"hide:char,string\")\n"
+"  7. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
 "+max,suffix,string\")\n"
 "     or max chars displayed on screen (format: \"cutscr:max,suffix,string\" "
 "or \"cutscr:+max,suffix,string\")\n"
-"  7. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
-"  8. a repeated string (format: \"repeat:count,string\")\n"
-"  9. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
-"  10. split of a string (format: \"split:number,separators,flags,xxx\")\n"
-"  11. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
-"  12. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
+"  8. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
+"  9. a repeated string (format: \"repeat:count,string\")\n"
+"  10. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
+"  11. split of a string (format: \"split:number,separators,flags,xxx\")\n"
+"  12. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
+"  13. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
 "\"color\")\n"
-"  13. a modifier (format: \"modifier:name,data,string\")\n"
-"  14. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  15. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"  14. a modifier (format: \"modifier:name,data,string\")\n"
+"  15. an info (format: \"info:name,arguments\", arguments are optional)\n"
+"  16. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
 "\" or \"base_decode:base,xxx\")\n"
-"  16. current date/time (format: \"date\" or \"date:format\")\n"
-"  17. an environment variable (format: \"env:XXX\")\n"
-"  18. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  17. current date/time (format: \"date\" or \"date:format\")\n"
+"  18. an environment variable (format: \"env:XXX\")\n"
+"  19. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  19. result of an expression with parentheses and operators + - * / // % ** "
+"  20. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  20. a random integer number (format: \"random:min,max\")\n"
-"  21. a translated string (format: \"translate:xxx\")\n"
-"  22. an option (format: \"file.section.option\")\n"
-"  23. a local variable in buffer\n"
-"  24. a hdata name/variable (the value is automatically converted to "
+"  21. a random integer number (format: \"random:min,max\")\n"
+"  22. a translated string (format: \"translate:xxx\")\n"
+"  23. define a user variable (format: \"define:name,value\")\n"
+"  24. an option (format: \"file.section.option\")\n"
+"  25. a local variable in buffer\n"
+"  26. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1882,38 +1884,39 @@ msgid ""
 "function \"weechat_hdata_get\".\n"
 "\n"
 "Examples (simple strings):\n"
-"  /eval -n ${raw:${info:version}}                ==> ${info:version}\n"
-"  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1\n"
-"  /eval -n ${info:version}                       ==> 0.4.3\n"
-"  /eval -n ${env:HOME}                           ==> /home/user\n"
-"  /eval -n ${weechat.look.scroll_amount}         ==> 3\n"
-"  /eval -n ${sec.data.password}                  ==> secret\n"
-"  /eval -n ${window}                             ==> 0x2549aa0\n"
-"  /eval -n ${window.buffer}                      ==> 0x2549320\n"
-"  /eval -n ${window.buffer.full_name}            ==> core.weechat\n"
-"  /eval -n ${window.buffer.number}               ==> 1\n"
-"  /eval -n ${\\t}                                 ==> <tab>\n"
-"  /eval -n ${hide:-,${relay.network.password}}   ==> --------\n"
-"  /eval -n ${cut:3,+,test}                       ==> tes+\n"
-"  /eval -n ${cut:+3,+,test}                      ==> te+\n"
-"  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40\n"
-"  /eval -n ${if:${info:term_width}>80?big:small} ==> big\n"
-"  /eval -n ${rev:Hello}                          ==> olleH\n"
-"  /eval -n ${repeat:5,-}                         ==> -----\n"
-"  /eval -n ${length:test}                        ==> 4\n"
-"  /eval -n ${split:1,,,abc,def,ghi}              ==> abc\n"
-"  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi\n"
-"  /eval -n ${split:count,,,abc,def,ghi}          ==> 3\n"
-"  /eval -n ${split:random,,,abc,def,ghi}         ==> def\n"
-"  /eval -n ${split_shell:1,\"arg 1\" arg2}         ==> arg 1\n"
-"  /eval -n ${split_shell:-1,\"arg 1\" arg2}        ==> arg2\n"
-"  /eval -n ${split_shell:count,\"arg 1\" arg2}     ==> 2\n"
-"  /eval -n ${split_shell:random,\"arg 1\" arg2}    ==> arg2\n"
-"  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
-"  /eval -n ${random:0,10}                        ==> 3\n"
-"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
-"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
-"  /eval -n ${translate:Plugin}                   ==> Extension\n"
+"  /eval -n ${raw:${info:version}}                 ==> ${info:version}\n"
+"  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1\n"
+"  /eval -n ${info:version}                        ==> 0.4.3\n"
+"  /eval -n ${env:HOME}                            ==> /home/user\n"
+"  /eval -n ${weechat.look.scroll_amount}          ==> 3\n"
+"  /eval -n ${sec.data.password}                   ==> secret\n"
+"  /eval -n ${window}                              ==> 0x2549aa0\n"
+"  /eval -n ${window.buffer}                       ==> 0x2549320\n"
+"  /eval -n ${window.buffer.full_name}             ==> core.weechat\n"
+"  /eval -n ${window.buffer.number}                ==> 1\n"
+"  /eval -n ${\\t}                                  ==> <tab>\n"
+"  /eval -n ${hide:-,${relay.network.password}}    ==> --------\n"
+"  /eval -n ${cut:3,+,test}                        ==> tes+\n"
+"  /eval -n ${cut:+3,+,test}                       ==> te+\n"
+"  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40\n"
+"  /eval -n ${if:${info:term_width}>80?big:small}  ==> big\n"
+"  /eval -n ${rev:Hello}                           ==> olleH\n"
+"  /eval -n ${repeat:5,-}                          ==> -----\n"
+"  /eval -n ${length:test}                         ==> 4\n"
+"  /eval -n ${split:1,,,abc,def,ghi}               ==> abc\n"
+"  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi\n"
+"  /eval -n ${split:count,,,abc,def,ghi}           ==> 3\n"
+"  /eval -n ${split:random,,,abc,def,ghi}          ==> def\n"
+"  /eval -n ${split_shell:1,\"arg 1\" arg2}          ==> arg 1\n"
+"  /eval -n ${split_shell:-1,\"arg 1\" arg2}         ==> arg2\n"
+"  /eval -n ${split_shell:count,\"arg 1\" arg2}      ==> 2\n"
+"  /eval -n ${split_shell:random,\"arg 1\" arg2}     ==> arg2\n"
+"  /eval -n ${calc:(5+2)*3}                        ==> 21\n"
+"  /eval -n ${random:0,10}                         ==> 3\n"
+"  /eval -n ${base_encode:64,test}                 ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}             ==> test\n"
+"  /eval -n ${translate:Plugin}                    ==> Extension\n"
+"  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/tr.po b/po/tr.po
index d08392101..087366d61 100644
--- a/po/tr.po
+++ b/po/tr.po
@@ -20,7 +20,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2021-09-09 21:07+0200\n"
+"POT-Creation-Date: 2021-09-20 21:12+0200\n"
 "PO-Revision-Date: 2021-07-10 16:01+0200\n"
 "Last-Translator: Emir SARI <bitigchi@me.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -1683,36 +1683,38 @@ msgid ""
 "Some variables are replaced in expression, using the format ${variable}, "
 "variable can be, by order of priority:\n"
 "  1. the string itself without evaluation (format: \"raw:xxx\")\n"
-"  2. an evaluated sub-string (format: \"eval:xxx\")\n"
-"  3. an evaluated condition (format: \"eval_cond:xxx\")\n"
-"  4. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
-"  5. a string with chars to hide (format: \"hide:char,string\")\n"
-"  6. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
+"  2. a user-defined variable (format: \"name\")\n"
+"  3. an evaluated sub-string (format: \"eval:xxx\")\n"
+"  4. an evaluated condition (format: \"eval_cond:xxx\")\n"
+"  5. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
+"  6. a string with chars to hide (format: \"hide:char,string\")\n"
+"  7. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
 "+max,suffix,string\")\n"
 "     or max chars displayed on screen (format: \"cutscr:max,suffix,string\" "
 "or \"cutscr:+max,suffix,string\")\n"
-"  7. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
-"  8. a repeated string (format: \"repeat:count,string\")\n"
-"  9. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
-"  10. split of a string (format: \"split:number,separators,flags,xxx\")\n"
-"  11. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
-"  12. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
+"  8. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
+"  9. a repeated string (format: \"repeat:count,string\")\n"
+"  10. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
+"  11. split of a string (format: \"split:number,separators,flags,xxx\")\n"
+"  12. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
+"  13. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
 "\"color\")\n"
-"  13. a modifier (format: \"modifier:name,data,string\")\n"
-"  14. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  15. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"  14. a modifier (format: \"modifier:name,data,string\")\n"
+"  15. an info (format: \"info:name,arguments\", arguments are optional)\n"
+"  16. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
 "\" or \"base_decode:base,xxx\")\n"
-"  16. current date/time (format: \"date\" or \"date:format\")\n"
-"  17. an environment variable (format: \"env:XXX\")\n"
-"  18. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  17. current date/time (format: \"date\" or \"date:format\")\n"
+"  18. an environment variable (format: \"env:XXX\")\n"
+"  19. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  19. result of an expression with parentheses and operators + - * / // % ** "
+"  20. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  20. a random integer number (format: \"random:min,max\")\n"
-"  21. a translated string (format: \"translate:xxx\")\n"
-"  22. an option (format: \"file.section.option\")\n"
-"  23. a local variable in buffer\n"
-"  24. a hdata name/variable (the value is automatically converted to "
+"  21. a random integer number (format: \"random:min,max\")\n"
+"  22. a translated string (format: \"translate:xxx\")\n"
+"  23. define a user variable (format: \"define:name,value\")\n"
+"  24. an option (format: \"file.section.option\")\n"
+"  25. a local variable in buffer\n"
+"  26. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1734,38 +1736,39 @@ msgid ""
 "function \"weechat_hdata_get\".\n"
 "\n"
 "Examples (simple strings):\n"
-"  /eval -n ${raw:${info:version}}                ==> ${info:version}\n"
-"  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1\n"
-"  /eval -n ${info:version}                       ==> 0.4.3\n"
-"  /eval -n ${env:HOME}                           ==> /home/user\n"
-"  /eval -n ${weechat.look.scroll_amount}         ==> 3\n"
-"  /eval -n ${sec.data.password}                  ==> secret\n"
-"  /eval -n ${window}                             ==> 0x2549aa0\n"
-"  /eval -n ${window.buffer}                      ==> 0x2549320\n"
-"  /eval -n ${window.buffer.full_name}            ==> core.weechat\n"
-"  /eval -n ${window.buffer.number}               ==> 1\n"
-"  /eval -n ${\\t}                                 ==> <tab>\n"
-"  /eval -n ${hide:-,${relay.network.password}}   ==> --------\n"
-"  /eval -n ${cut:3,+,test}                       ==> tes+\n"
-"  /eval -n ${cut:+3,+,test}                      ==> te+\n"
-"  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40\n"
-"  /eval -n ${if:${info:term_width}>80?big:small} ==> big\n"
-"  /eval -n ${rev:Hello}                          ==> olleH\n"
-"  /eval -n ${repeat:5,-}                         ==> -----\n"
-"  /eval -n ${length:test}                        ==> 4\n"
-"  /eval -n ${split:1,,,abc,def,ghi}              ==> abc\n"
-"  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi\n"
-"  /eval -n ${split:count,,,abc,def,ghi}          ==> 3\n"
-"  /eval -n ${split:random,,,abc,def,ghi}         ==> def\n"
-"  /eval -n ${split_shell:1,\"arg 1\" arg2}         ==> arg 1\n"
-"  /eval -n ${split_shell:-1,\"arg 1\" arg2}        ==> arg2\n"
-"  /eval -n ${split_shell:count,\"arg 1\" arg2}     ==> 2\n"
-"  /eval -n ${split_shell:random,\"arg 1\" arg2}    ==> arg2\n"
-"  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
-"  /eval -n ${random:0,10}                        ==> 3\n"
-"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
-"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
-"  /eval -n ${translate:Plugin}                   ==> Extension\n"
+"  /eval -n ${raw:${info:version}}                 ==> ${info:version}\n"
+"  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1\n"
+"  /eval -n ${info:version}                        ==> 0.4.3\n"
+"  /eval -n ${env:HOME}                            ==> /home/user\n"
+"  /eval -n ${weechat.look.scroll_amount}          ==> 3\n"
+"  /eval -n ${sec.data.password}                   ==> secret\n"
+"  /eval -n ${window}                              ==> 0x2549aa0\n"
+"  /eval -n ${window.buffer}                       ==> 0x2549320\n"
+"  /eval -n ${window.buffer.full_name}             ==> core.weechat\n"
+"  /eval -n ${window.buffer.number}                ==> 1\n"
+"  /eval -n ${\\t}                                  ==> <tab>\n"
+"  /eval -n ${hide:-,${relay.network.password}}    ==> --------\n"
+"  /eval -n ${cut:3,+,test}                        ==> tes+\n"
+"  /eval -n ${cut:+3,+,test}                       ==> te+\n"
+"  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40\n"
+"  /eval -n ${if:${info:term_width}>80?big:small}  ==> big\n"
+"  /eval -n ${rev:Hello}                           ==> olleH\n"
+"  /eval -n ${repeat:5,-}                          ==> -----\n"
+"  /eval -n ${length:test}                         ==> 4\n"
+"  /eval -n ${split:1,,,abc,def,ghi}               ==> abc\n"
+"  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi\n"
+"  /eval -n ${split:count,,,abc,def,ghi}           ==> 3\n"
+"  /eval -n ${split:random,,,abc,def,ghi}          ==> def\n"
+"  /eval -n ${split_shell:1,\"arg 1\" arg2}          ==> arg 1\n"
+"  /eval -n ${split_shell:-1,\"arg 1\" arg2}         ==> arg2\n"
+"  /eval -n ${split_shell:count,\"arg 1\" arg2}      ==> 2\n"
+"  /eval -n ${split_shell:random,\"arg 1\" arg2}     ==> arg2\n"
+"  /eval -n ${calc:(5+2)*3}                        ==> 21\n"
+"  /eval -n ${random:0,10}                         ==> 3\n"
+"  /eval -n ${base_encode:64,test}                 ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}             ==> test\n"
+"  /eval -n ${translate:Plugin}                    ==> Extension\n"
+"  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/weechat.pot b/po/weechat.pot
index 911b5a973..f2a445dc8 100644
--- a/po/weechat.pot
+++ b/po/weechat.pot
@@ -21,7 +21,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2021-09-09 21:07+0200\n"
+"POT-Creation-Date: 2021-09-20 21:12+0200\n"
 "PO-Revision-Date: 2014-08-16 10:27+0200\n"
 "Last-Translator: Sébastien Helleu <flashcode@flashtux.org>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -1369,36 +1369,38 @@ msgid ""
 "Some variables are replaced in expression, using the format ${variable}, "
 "variable can be, by order of priority:\n"
 "  1. the string itself without evaluation (format: \"raw:xxx\")\n"
-"  2. an evaluated sub-string (format: \"eval:xxx\")\n"
-"  3. an evaluated condition (format: \"eval_cond:xxx\")\n"
-"  4. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
-"  5. a string with chars to hide (format: \"hide:char,string\")\n"
-"  6. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
+"  2. a user-defined variable (format: \"name\")\n"
+"  3. an evaluated sub-string (format: \"eval:xxx\")\n"
+"  4. an evaluated condition (format: \"eval_cond:xxx\")\n"
+"  5. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
+"  6. a string with chars to hide (format: \"hide:char,string\")\n"
+"  7. a string with max chars (format: \"cut:max,suffix,string\" or \"cut:"
 "+max,suffix,string\")\n"
 "     or max chars displayed on screen (format: \"cutscr:max,suffix,string\" "
 "or \"cutscr:+max,suffix,string\")\n"
-"  7. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
-"  8. a repeated string (format: \"repeat:count,string\")\n"
-"  9. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
-"  10. split of a string (format: \"split:number,separators,flags,xxx\")\n"
-"  11. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
-"  12. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
+"  8. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
+"  9. a repeated string (format: \"repeat:count,string\")\n"
+"  10. length of a string (format: \"length:xxx\" or \"lengthscr:xxx\")\n"
+"  11. split of a string (format: \"split:number,separators,flags,xxx\")\n"
+"  12. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
+"  13. a color (format: \"color:xxx\", see \"Plugin API reference\", function "
 "\"color\")\n"
-"  13. a modifier (format: \"modifier:name,data,string\")\n"
-"  14. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  15. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"  14. a modifier (format: \"modifier:name,data,string\")\n"
+"  15. an info (format: \"info:name,arguments\", arguments are optional)\n"
+"  16. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
 "\" or \"base_decode:base,xxx\")\n"
-"  16. current date/time (format: \"date\" or \"date:format\")\n"
-"  17. an environment variable (format: \"env:XXX\")\n"
-"  18. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  17. current date/time (format: \"date\" or \"date:format\")\n"
+"  18. an environment variable (format: \"env:XXX\")\n"
+"  19. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  19. result of an expression with parentheses and operators + - * / // % ** "
+"  20. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  20. a random integer number (format: \"random:min,max\")\n"
-"  21. a translated string (format: \"translate:xxx\")\n"
-"  22. an option (format: \"file.section.option\")\n"
-"  23. a local variable in buffer\n"
-"  24. a hdata name/variable (the value is automatically converted to "
+"  21. a random integer number (format: \"random:min,max\")\n"
+"  22. a translated string (format: \"translate:xxx\")\n"
+"  23. define a user variable (format: \"define:name,value\")\n"
+"  24. an option (format: \"file.section.option\")\n"
+"  25. a local variable in buffer\n"
+"  26. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1420,38 +1422,39 @@ msgid ""
 "function \"weechat_hdata_get\".\n"
 "\n"
 "Examples (simple strings):\n"
-"  /eval -n ${raw:${info:version}}                ==> ${info:version}\n"
-"  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1\n"
-"  /eval -n ${info:version}                       ==> 0.4.3\n"
-"  /eval -n ${env:HOME}                           ==> /home/user\n"
-"  /eval -n ${weechat.look.scroll_amount}         ==> 3\n"
-"  /eval -n ${sec.data.password}                  ==> secret\n"
-"  /eval -n ${window}                             ==> 0x2549aa0\n"
-"  /eval -n ${window.buffer}                      ==> 0x2549320\n"
-"  /eval -n ${window.buffer.full_name}            ==> core.weechat\n"
-"  /eval -n ${window.buffer.number}               ==> 1\n"
-"  /eval -n ${\\t}                                 ==> <tab>\n"
-"  /eval -n ${hide:-,${relay.network.password}}   ==> --------\n"
-"  /eval -n ${cut:3,+,test}                       ==> tes+\n"
-"  /eval -n ${cut:+3,+,test}                      ==> te+\n"
-"  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40\n"
-"  /eval -n ${if:${info:term_width}>80?big:small} ==> big\n"
-"  /eval -n ${rev:Hello}                          ==> olleH\n"
-"  /eval -n ${repeat:5,-}                         ==> -----\n"
-"  /eval -n ${length:test}                        ==> 4\n"
-"  /eval -n ${split:1,,,abc,def,ghi}              ==> abc\n"
-"  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi\n"
-"  /eval -n ${split:count,,,abc,def,ghi}          ==> 3\n"
-"  /eval -n ${split:random,,,abc,def,ghi}         ==> def\n"
-"  /eval -n ${split_shell:1,\"arg 1\" arg2}         ==> arg 1\n"
-"  /eval -n ${split_shell:-1,\"arg 1\" arg2}        ==> arg2\n"
-"  /eval -n ${split_shell:count,\"arg 1\" arg2}     ==> 2\n"
-"  /eval -n ${split_shell:random,\"arg 1\" arg2}    ==> arg2\n"
-"  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
-"  /eval -n ${random:0,10}                        ==> 3\n"
-"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
-"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
-"  /eval -n ${translate:Plugin}                   ==> Extension\n"
+"  /eval -n ${raw:${info:version}}                 ==> ${info:version}\n"
+"  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1\n"
+"  /eval -n ${info:version}                        ==> 0.4.3\n"
+"  /eval -n ${env:HOME}                            ==> /home/user\n"
+"  /eval -n ${weechat.look.scroll_amount}          ==> 3\n"
+"  /eval -n ${sec.data.password}                   ==> secret\n"
+"  /eval -n ${window}                              ==> 0x2549aa0\n"
+"  /eval -n ${window.buffer}                       ==> 0x2549320\n"
+"  /eval -n ${window.buffer.full_name}             ==> core.weechat\n"
+"  /eval -n ${window.buffer.number}                ==> 1\n"
+"  /eval -n ${\\t}                                  ==> <tab>\n"
+"  /eval -n ${hide:-,${relay.network.password}}    ==> --------\n"
+"  /eval -n ${cut:3,+,test}                        ==> tes+\n"
+"  /eval -n ${cut:+3,+,test}                       ==> te+\n"
+"  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40\n"
+"  /eval -n ${if:${info:term_width}>80?big:small}  ==> big\n"
+"  /eval -n ${rev:Hello}                           ==> olleH\n"
+"  /eval -n ${repeat:5,-}                          ==> -----\n"
+"  /eval -n ${length:test}                         ==> 4\n"
+"  /eval -n ${split:1,,,abc,def,ghi}               ==> abc\n"
+"  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi\n"
+"  /eval -n ${split:count,,,abc,def,ghi}           ==> 3\n"
+"  /eval -n ${split:random,,,abc,def,ghi}          ==> def\n"
+"  /eval -n ${split_shell:1,\"arg 1\" arg2}          ==> arg 1\n"
+"  /eval -n ${split_shell:-1,\"arg 1\" arg2}         ==> arg2\n"
+"  /eval -n ${split_shell:count,\"arg 1\" arg2}      ==> 2\n"
+"  /eval -n ${split_shell:random,\"arg 1\" arg2}     ==> arg2\n"
+"  /eval -n ${calc:(5+2)*3}                        ==> 21\n"
+"  /eval -n ${random:0,10}                         ==> 3\n"
+"  /eval -n ${base_encode:64,test}                 ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}             ==> test\n"
+"  /eval -n ${translate:Plugin}                    ==> Extension\n"
+"  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/src/core/wee-command.c b/src/core/wee-command.c
index a4ae9d15a..71ff892d7 100644
--- a/src/core/wee-command.c
+++ b/src/core/wee-command.c
@@ -7658,40 +7658,42 @@ command_init ()
            "Some variables are replaced in expression, using the format "
            "${variable}, variable can be, by order of priority:\n"
            "  1. the string itself without evaluation (format: \"raw:xxx\")\n"
-           "  2. an evaluated sub-string (format: \"eval:xxx\")\n"
-           "  3. an evaluated condition (format: \"eval_cond:xxx\")\n"
-           "  4. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
-           "  5. a string with chars to hide (format: \"hide:char,string\")\n"
-           "  6. a string with max chars (format: \"cut:max,suffix,string\" "
+           "  2. a user-defined variable (format: \"name\")\n"
+           "  3. an evaluated sub-string (format: \"eval:xxx\")\n"
+           "  4. an evaluated condition (format: \"eval_cond:xxx\")\n"
+           "  5. a string with escaped chars (format: \"esc:xxx\" or \"\\xxx\")\n"
+           "  6. a string with chars to hide (format: \"hide:char,string\")\n"
+           "  7. a string with max chars (format: \"cut:max,suffix,string\" "
            "or \"cut:+max,suffix,string\")\n"
            "     or max chars displayed on screen "
            "(format: \"cutscr:max,suffix,string\" or "
            "\"cutscr:+max,suffix,string\")\n"
-           "  7. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
-           "  8. a repeated string (format: \"repeat:count,string\")\n"
-           "  9. length of a string (format: \"length:xxx\" or "
+           "  8. a reversed string (format: \"rev:xxx\" or \"revscr:xxx\")\n"
+           "  9. a repeated string (format: \"repeat:count,string\")\n"
+           "  10. length of a string (format: \"length:xxx\" or "
            "\"lengthscr:xxx\")\n"
-           "  10. split of a string (format: "
+           "  11. split of a string (format: "
            "\"split:number,separators,flags,xxx\")\n"
-           "  11. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
-           "  12. a color (format: \"color:xxx\", see \"Plugin API "
+           "  12. split of shell argmuents (format: \"split_shell:number,xxx\")\n"
+           "  13. a color (format: \"color:xxx\", see \"Plugin API "
            "reference\", function \"color\")\n"
-           "  13. a modifier (format: \"modifier:name,data,string\")\n"
-           "  14. an info (format: \"info:name,arguments\", arguments are "
+           "  14. a modifier (format: \"modifier:name,data,string\")\n"
+           "  15. an info (format: \"info:name,arguments\", arguments are "
            "optional)\n"
-           "  15. a base 16/32/64 encoded/decoded string (format: "
+           "  16. a base 16/32/64 encoded/decoded string (format: "
            "\"base_encode:base,xxx\" or \"base_decode:base,xxx\")\n"
-           "  16. current date/time (format: \"date\" or \"date:format\")\n"
-           "  17. an environment variable (format: \"env:XXX\")\n"
-           "  18. a ternary operator (format: "
+           "  17. current date/time (format: \"date\" or \"date:format\")\n"
+           "  18. an environment variable (format: \"env:XXX\")\n"
+           "  19. a ternary operator (format: "
            "\"if:condition?value_if_true:value_if_false\")\n"
-           "  19. result of an expression with parentheses and operators "
+           "  20. result of an expression with parentheses and operators "
            "+ - * / // % ** (format: \"calc:xxx\")\n"
-           "  20. a random integer number (format: \"random:min,max\")\n"
-           "  21. a translated string (format: \"translate:xxx\")\n"
-           "  22. an option (format: \"file.section.option\")\n"
-           "  23. a local variable in buffer\n"
-           "  24. a hdata name/variable (the value is automatically converted "
+           "  21. a random integer number (format: \"random:min,max\")\n"
+           "  22. a translated string (format: \"translate:xxx\")\n"
+           "  23. define a user variable (format: \"define:name,value\")\n"
+           "  24. an option (format: \"file.section.option\")\n"
+           "  25. a local variable in buffer\n"
+           "  26. a hdata name/variable (the value is automatically converted "
            "to string), by default \"window\" and \"buffer\" point to current "
            "window/buffer.\n"
            "Format for hdata can be one of following:\n"
@@ -7713,38 +7715,39 @@ command_init ()
            "reference\", function \"weechat_hdata_get\".\n"
            "\n"
            "Examples (simple strings):\n"
-           "  /eval -n ${raw:${info:version}}                ==> ${info:version}\n"
-           "  /eval -n ${eval_cond:${window.win_width}>100}  ==> 1\n"
-           "  /eval -n ${info:version}                       ==> 0.4.3\n"
-           "  /eval -n ${env:HOME}                           ==> /home/user\n"
-           "  /eval -n ${weechat.look.scroll_amount}         ==> 3\n"
-           "  /eval -n ${sec.data.password}                  ==> secret\n"
-           "  /eval -n ${window}                             ==> 0x2549aa0\n"
-           "  /eval -n ${window.buffer}                      ==> 0x2549320\n"
-           "  /eval -n ${window.buffer.full_name}            ==> core.weechat\n"
-           "  /eval -n ${window.buffer.number}               ==> 1\n"
-           "  /eval -n ${\\t}                                 ==> <tab>\n"
-           "  /eval -n ${hide:-,${relay.network.password}}   ==> --------\n"
-           "  /eval -n ${cut:3,+,test}                       ==> tes+\n"
-           "  /eval -n ${cut:+3,+,test}                      ==> te+\n"
-           "  /eval -n ${date:%H:%M:%S}                      ==> 07:46:40\n"
-           "  /eval -n ${if:${info:term_width}>80?big:small} ==> big\n"
-           "  /eval -n ${rev:Hello}                          ==> olleH\n"
-           "  /eval -n ${repeat:5,-}                         ==> -----\n"
-           "  /eval -n ${length:test}                        ==> 4\n"
-           "  /eval -n ${split:1,,,abc,def,ghi}              ==> abc\n"
-           "  /eval -n ${split:-1,,,abc,def,ghi}             ==> ghi\n"
-           "  /eval -n ${split:count,,,abc,def,ghi}          ==> 3\n"
-           "  /eval -n ${split:random,,,abc,def,ghi}         ==> def\n"
-           "  /eval -n ${split_shell:1,\"arg 1\" arg2}         ==> arg 1\n"
-           "  /eval -n ${split_shell:-1,\"arg 1\" arg2}        ==> arg2\n"
-           "  /eval -n ${split_shell:count,\"arg 1\" arg2}     ==> 2\n"
-           "  /eval -n ${split_shell:random,\"arg 1\" arg2}    ==> arg2\n"
-           "  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
-           "  /eval -n ${random:0,10}                        ==> 3\n"
-           "  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
-           "  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
-           "  /eval -n ${translate:Plugin}                   ==> Extension\n"
+           "  /eval -n ${raw:${info:version}}                 ==> ${info:version}\n"
+           "  /eval -n ${eval_cond:${window.win_width}>100}   ==> 1\n"
+           "  /eval -n ${info:version}                        ==> 0.4.3\n"
+           "  /eval -n ${env:HOME}                            ==> /home/user\n"
+           "  /eval -n ${weechat.look.scroll_amount}          ==> 3\n"
+           "  /eval -n ${sec.data.password}                   ==> secret\n"
+           "  /eval -n ${window}                              ==> 0x2549aa0\n"
+           "  /eval -n ${window.buffer}                       ==> 0x2549320\n"
+           "  /eval -n ${window.buffer.full_name}             ==> core.weechat\n"
+           "  /eval -n ${window.buffer.number}                ==> 1\n"
+           "  /eval -n ${\\t}                                  ==> <tab>\n"
+           "  /eval -n ${hide:-,${relay.network.password}}    ==> --------\n"
+           "  /eval -n ${cut:3,+,test}                        ==> tes+\n"
+           "  /eval -n ${cut:+3,+,test}                       ==> te+\n"
+           "  /eval -n ${date:%H:%M:%S}                       ==> 07:46:40\n"
+           "  /eval -n ${if:${info:term_width}>80?big:small}  ==> big\n"
+           "  /eval -n ${rev:Hello}                           ==> olleH\n"
+           "  /eval -n ${repeat:5,-}                          ==> -----\n"
+           "  /eval -n ${length:test}                         ==> 4\n"
+           "  /eval -n ${split:1,,,abc,def,ghi}               ==> abc\n"
+           "  /eval -n ${split:-1,,,abc,def,ghi}              ==> ghi\n"
+           "  /eval -n ${split:count,,,abc,def,ghi}           ==> 3\n"
+           "  /eval -n ${split:random,,,abc,def,ghi}          ==> def\n"
+           "  /eval -n ${split_shell:1,\"arg 1\" arg2}          ==> arg 1\n"
+           "  /eval -n ${split_shell:-1,\"arg 1\" arg2}         ==> arg2\n"
+           "  /eval -n ${split_shell:count,\"arg 1\" arg2}      ==> 2\n"
+           "  /eval -n ${split_shell:random,\"arg 1\" arg2}     ==> arg2\n"
+           "  /eval -n ${calc:(5+2)*3}                        ==> 21\n"
+           "  /eval -n ${random:0,10}                         ==> 3\n"
+           "  /eval -n ${base_encode:64,test}                 ==> dGVzdA==\n"
+           "  /eval -n ${base_decode:64,dGVzdA==}             ==> test\n"
+           "  /eval -n ${translate:Plugin}                    ==> Extension\n"
+           "  /eval -n ${define:len,${calc:5+3}}${len}x${len} ==> 8x8\n"
            "\n"
            "Examples (conditions):\n"
            "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/src/core/wee-eval.c b/src/core/wee-eval.c
index 3135380d5..6c1fd22ec 100644
--- a/src/core/wee-eval.c
+++ b/src/core/wee-eval.c
@@ -1069,6 +1069,28 @@ eval_string_translate (const char *text)
 }
 
 /*
+ * Defines a variable.
+ */
+
+void
+eval_string_define (const char *text, struct t_eval_context *eval_context)
+{
+    char *pos, *name;
+
+    pos = strchr (text, ',');
+    if (!pos)
+        return;
+
+    name = strndup (text, pos - text);
+    if (!name)
+        return;
+
+    hashtable_set (eval_context->user_vars, name, pos + 1);
+
+    free (name);
+}
+
+/*
  * Gets value of hdata using "path" to a variable.
  *
  * Note: result must be freed after use.
@@ -1352,7 +1374,7 @@ end:
 /*
  * Replaces variables, which can be, by order of priority:
  *   1. the string itself without evaluation (format: raw:xxx)
- *   2. an extra variable from hashtable "extra_vars"
+ *   2. a variable from hashtable "user_vars" or "extra_vars"
  *   3. a WeeChat home directory, one of: "weechat_config_dir",
  *      "weechat_data_dir", "weechat_cache_dir", "weechat_runtime_dir"
  *   4. a string to evaluate (format: eval:xxx)
@@ -1421,7 +1443,13 @@ eval_replace_vars_cb (void *data, const char *text)
         goto end;
     }
 
-    /* 2. variable in hashtable "extra_vars" */
+    /* 2. variable in hashtable "user_vars" or "extra_vars" */
+    ptr_value = hashtable_get (eval_context->user_vars, text);
+    if (ptr_value)
+    {
+        value = strdup (ptr_value);
+        goto end;
+    }
     if (eval_context->extra_vars)
     {
         ptr_value = hashtable_get (eval_context->extra_vars, text);
@@ -1668,6 +1696,14 @@ eval_replace_vars_cb (void *data, const char *text)
         goto end;
     }
 
+    /* 25. define a variable */
+    if (strncmp (text, "define:", 7) == 0)
+    {
+        eval_string_define (text + 7, eval_context);
+        value = strdup ("");
+        goto end;
+    }
+
     /* 25. option: if found, return this value */
     if (strncmp (text, "sec.data.", 9) == 0)
     {
@@ -2333,6 +2369,7 @@ eval_expression (const char *expr, struct t_hashtable *pointers,
                  struct t_hashtable *extra_vars, struct t_hashtable *options)
 {
     struct t_eval_context context, *eval_context;
+    struct t_hashtable *user_vars;
     int condition, rc, pointers_allocated, regex_allocated, debug_id;
     int ptr_window_added, ptr_buffer_added;
     long number;
@@ -2347,6 +2384,7 @@ eval_expression (const char *expr, struct t_hashtable *pointers,
         return NULL;
 
     condition = 0;
+    user_vars = NULL;
     pointers_allocated = 0;
     regex_allocated = 0;
     regex = NULL;
@@ -2371,10 +2409,17 @@ eval_expression (const char *expr, struct t_hashtable *pointers,
         pointers_allocated = 1;
     }
 
+    user_vars = hashtable_new (32,
+                               WEECHAT_HASHTABLE_STRING,
+                               WEECHAT_HASHTABLE_STRING,
+                               NULL,
+                               NULL);
+
     eval_context = &context;
 
     eval_context->pointers = pointers;
     eval_context->extra_vars = extra_vars;
+    eval_context->user_vars = user_vars;
     eval_context->extra_vars_eval = 0;
     eval_context->prefix = default_prefix;
     eval_context->suffix = default_suffix;
@@ -2506,6 +2551,8 @@ eval_expression (const char *expr, struct t_hashtable *pointers,
         if (ptr_buffer_added)
             hashtable_remove (pointers, "buffer");
     }
+    if (user_vars)
+        hashtable_free (user_vars);
     if (regex && regex_allocated)
     {
         regfree (regex);
diff --git a/src/core/wee-eval.h b/src/core/wee-eval.h
index 5c97b7a31..03b33a421 100644
--- a/src/core/wee-eval.h
+++ b/src/core/wee-eval.h
@@ -73,6 +73,7 @@ struct t_eval_context
 {
     struct t_hashtable *pointers;      /* pointers used in eval             */
     struct t_hashtable *extra_vars;    /* extra variables used in eval      */
+    struct t_hashtable *user_vars;     /* user-defined variables            */
     int extra_vars_eval;               /* 1 if extra vars must be evaluated */
     const char *prefix;                /* prefix (default is "${")          */
     const char *suffix;                /* suffix (default is "}")           */
diff --git a/tests/unit/core/test-core-eval.cpp b/tests/unit/core/test-core-eval.cpp
index 6e9582ca9..d5d1906d2 100644
--- a/tests/unit/core/test-core-eval.cpp
+++ b/tests/unit/core/test-core-eval.cpp
@@ -853,6 +853,14 @@ TEST(CoreEval, EvalExpression)
     WEE_CHECK_EVAL("", "${translate:}");
     WEE_CHECK_EVAL("abcdef", "${translate:abcdef}");
 
+    /* test user variables */
+    WEE_CHECK_EVAL("", "${define:}");
+    WEE_CHECK_EVAL("", "${define:test}");
+    WEE_CHECK_EVAL("", "${define:test,value}");
+    WEE_CHECK_EVAL("value", "${define:test,value}${test}");
+    WEE_CHECK_EVAL("8", "${define:test,${calc:5+3}}${test}");
+    WEE_CHECK_EVAL("value", "${define:buffer,value}${buffer}");
+
     /* test option */
     hashtable_set (secure_hashtable_data, "sec_option", "sec_value");
     WEE_CHECK_EVAL("sec_value", "${sec.data.sec_option}");