.\" $OpenBSD: more.1,v 1.12 2020/01/16 16:46:46 schwarze Exp $
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.\" Copyright (c) 1980 The Regents of the University of California.
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.\" modification, are permitted provided that the following conditions
.\" are met:
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.\"    notice, this list of conditions and the following disclaimer in the
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.\"    may be used to endorse or promote products derived from this software
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.\"	@(#)more.1	5.15 (Berkeley) 7/29/91
.\"
.Dd $Mdocdate: January 16 2020 $
.Dt MORE 1
.Os
.Sh NAME
.Nm more , page
.Nd view files
.Sh SYNOPSIS
.Nm more
.Op Fl cdflpsu
.Op \- Ns Ar num
.Op + Ns Ar linenumber
.Op +/ Ns Ar pattern
.Op Ar
.Nm page
.Op Fl cdflpsu
.Op \- Ns Ar num
.Op + Ns Ar linenumber
.Op +/ Ns Ar pattern
.Op Ar
.Sh DESCRIPTION
.Nm more
is a filter which allows examination of a continuous text
one screenful at a time on a soft-copy terminal.
It normally pauses after each screenful, printing --More--
at the bottom of the screen.
If the user then types a carriage return, one more line is displayed.
If the user hits a space, another screenful is displayed.
Other possibilities are enumerated later.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl c
.Nm
will draw each page by beginning at the top of the screen and erasing
each line just before it draws on it.
This avoids scrolling the screen, making it easier to read while
.Nm
is writing.
This option will be ignored if the terminal does not have the ability
to clear to the end of a line.
.It Fl d
.Nm
will prompt the user with the message "[Press space to continue, 'q' to
quit.]" at the end of each screenful, and will display
"[Press 'h' for instructions.]" instead of ringing the bell when an
illegal key is pressed.
This is useful if
.Nm
is being used as a filter in some setting, such as a class,
where many users may be unsophisticated.
.It Fl f
Causes
.Nm
to count logical, rather than screen lines (i.e., long lines are not folded).
This option is recommended if
.Xr mandoc 1
output is being piped through
.Xr ul 1 ,
since the latter may generate escape sequences.
These escape sequences contain characters which would ordinarily occupy
screen positions, but which do not print when they are sent to the
terminal as part of an escape sequence.
Thus,
.Nm
may think that lines are longer than they actually are, and fold
lines erroneously.
.It Fl l
Do
not treat
.Ic ^\&L
(form feed) specially.
If this option is not given,
.Nm
will pause after any line that contains a
.Ic ^\&L ,
as if the end of a screenful had been reached.
Also, if a file begins with a form feed, the screen will be cleared
before the file is printed.
.It Fl p
A deprecated alias for the
.Fl c
option.
.It Fl s
Squeeze multiple blank lines from the output, producing only one blank
line.
This maximizes the useful information present on the screen.
.It Fl u
Suppress underlining.
Normally,
.Nm
will handle underlining such as produced by
.Xr mandoc 1
in a manner appropriate to the particular terminal:
if the terminal can perform underlining or has a stand-out mode,
.Nm
will output appropriate escape sequences to enable underlining or stand-out
mode for underlined information in the source file.
.It \- Ns Ar num
An integer specifying the size (in lines) of the window which
.Nm
will use instead of the default.
On a terminal capable of displaying 24 lines, the default
window size is 23 lines.
.It + Ns Ar linenumber
Start at the specified
.Ar linenumber .
.It +/ Ns Ar pattern
Start two lines before the line matching the
regular expression
.Ar pattern .
.El
.Pp
If the program is invoked as
.Nm page ,
then the screen is cleared before each screenful is printed (but only
if a full screenful is being printed).
.Pp
If
.Nm
is reading from a file, rather than a pipe, then a percentage is displayed
along with the --More-- prompt.
This gives the fraction of the file (in characters, not lines) that has been
read so far.
.Ss Command Sequences
Command sequences (similar to
.Xr vi 1 )
may be typed when
.Nm
pauses.
In the following list,
.Em i
is an optional integer argument, defaulting to 1.
In the following descriptions, ^X means control-X.
.Bl -tag -width Ds
.It Em i Ns Aq space
Display
.Em i
more lines, (or another screenful if no argument is given).
.It ^D
Display 11 more lines (a
.Dq scroll ) .
If
.Em i
is given, then the scroll size is set to
.Em i .
.It d
Same as ^D (control-D).
.It Em i Ns z
Same as typing a space except that
.Em i ,
if present, becomes the new window size.
.It Em i Ns s
Skip
.Em i
lines and print a screenful of lines.
.It Em i Ns f
Skip
.Em i
screenfuls and print a screenful of lines.
.It Em i Ns b
Skip back
.Em i
screenfuls and print a screenful of lines.
.It Em i Ns ^B
Same as
.Sq b .
.It q
Exit from
.Nm more .
.It Q
Same as
.Sq q .
.It =
Display the current line number.
.It v
Start up the editor at the current line.
.It h
Help command; give a description of all the
.Nm
commands.
.It Em i Ns / Ar expr
Search for the
.Em i Ns -th
occurrence of the regular expression
.Ar expr .
If there are less than
.Em i
occurrences of
.Ar expr
and the input is a file (rather than a pipe),
then the position in the file remains unchanged.
Otherwise, a screenful is displayed, starting two lines before the place
where the expression was found.
The user's erase and kill characters may be used to edit the regular
expression.
Erasing back past the first column cancels the search command.
.It Em i Ns n
Search for the
.Em i Ns -th
occurrence of the last regular expression entered.
.It \&' (single quote)
Go to the point from which the last search started.
If no search has been performed in the current file, this command
goes back to the beginning of the file.
.It ! Ns Ar command
Invoke a shell with
.Ar command .
The characters
.Sq %
and
.Sq !\&
in
.Ar command
are replaced with the current file name and the previous shell command
respectively.
If there is no current file name,
.Sq %
is not expanded.
The sequences
.Sq \e%
and
.Sq \e!
are replaced by
.Sq %
and
.Sq !\&
respectively.
.It Em i : Ns Ar n
Skip to the
.Ar i Ns -th
next file given in the command line (skips to last file if
.Ar n
doesn't make sense).
.It Em i : Ns Ar p
Skip to the
.Ar i Ns -th
previous file given in the command line.
If this command is given in the middle of printing out a file,
.Nm
goes back to the beginning of the file.
If
.Ar i
doesn't make sense,
.Nm
skips back to the first file.
If
.Nm
is not reading from a file, the bell is rung and nothing else happens.
.It :f
Display the current file name and line number.
.It :q or :Q
Exit from
.Nm
(same as q or Q).
.It \&. (dot)
Repeat the previous command.
.El
.Pp
Commands take effect immediately, i.e., it is not necessary to
type a carriage return.
Up to the time when the command character itself is given,
the user may hit the line kill character to cancel the numerical
argument being formed.
In addition, the user may hit the erase character to redisplay the
--More--(xx%) message.
.Pp
At any time when output is being sent to the terminal, the user can
hit the quit key (normally control\-\e).
.Nm
will stop sending output, and will display the usual --More--
prompt.
The user may then enter one of the above commands in the normal manner.
Unfortunately, some output is lost when this is done, due to the
fact that any characters waiting in the terminal's output queue
are flushed when the quit signal occurs.
.Pp
The terminal is set to
.Dq noecho
mode by this program so that the output can be continuous.
What you type will thus not show on your terminal, except for the / and !\&
commands.
.Pp
If the standard output is not a teletype, then
.Nm
acts just like
.Xr cat 1 ,
except that a header is printed before each file (if there is
more than one).
.Sh ENVIRONMENT
.Bl -tag -width Ds
.It Ev EDITOR
Editor to be used by the
.Ic v
command.
.It Ev MORE
A space-separated list of flags to pre-set when running
.Nm more .
Note that flags on the command line override those found in
.Ev MORE .
.It Ev SHELL
Shell to be used when running commands.
If this variable is not set,
.Pa /bin/sh
is used.
.It Ev TERM
The user's terminal type.
.It Ev VISUAL
Editor used in preference to that specified by
.Ev EDITOR .
.El
.Sh FILES
.Bl -tag -width /usr/share/misc/omore.helpXX -compact
.It Pa /usr/share/misc/termcap
Terminal data base
.It Pa /usr/bin/vi
Default editor
.El
.Sh EXAMPLES
A sample usage of
.Nm
in previewing
.Xr mandoc 1
output would be:
.Pp
.Dl mandoc doc.1 | more
.Sh SEE ALSO
.Xr cat 1 ,
.Xr mandoc 1 ,
.Xr sh 1 ,
.Xr ul 1 ,
.Xr vi 1 ,
.Xr environ 7
.Sh HISTORY
The
.Nm
command appeared in
.Bx 3.0 .
.Sh BUGS
Skipping backwards is too slow on large files.