Implement -I option: ignore changes matching a set of regexes. From

Jared Yanovich, with twists from millert@ and me. Testing by brad@,
sturm@ and pval@. ok millert@

1 files changed, 35 insertions, 14 deletions

diff --git a/usr.bin/diff/diff.1 b/usr.bin/diff/diff.1
index 633c2f435c0..48668dfd229 100644
--- a/usr.bin/diff/diff.1
+++ b/usr.bin/diff/diff.1
@@ -1,4 +1,4 @@
-.\" $OpenBSD: diff.1,v 1.25 2004/03/16 00:40:34 millert Exp $
+.\" $OpenBSD: diff.1,v 1.26 2004/06/20 18:47:45 otto Exp $
 .\"
 .\" Copyright (c) 1980, 1990, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -38,31 +38,36 @@
 .Sh SYNOPSIS
 .Nm diff
 .Op Fl abdilpqtTw
+.Op Fl I Ar pattern
 .Oo
-.Fl c | Fl e | Fl f |
-.Fl n | Fl u
+.Fl c | e | f |
+.Fl n | u
 .Oc
 .Op Fl L Ar label
 .Ar file1 file2
 .Nm diff
 .Op Fl abdilpqtTw
+.Op Fl I Ar pattern
 .Op Fl L Ar label
 .Fl C Ar number
 .Ar file1 file2
 .Nm diff
 .Op Fl abdilqtw
+.Op Fl I Ar pattern
 .Fl D Ar string
 .Ar file1 file2
 .Nm diff
 .Op Fl abdilpqtTw
+.Op Fl I Ar pattern
 .Op Fl L Ar label
 .Fl U Ar number
 .Ar file1 file2
 .Nm diff
 .Op Fl abdilNPpqtTw
+.Op Fl I Ar pattern
 .Oo
-.Fl c | Fl e | Fl f |
-.Fl n | Fl u
+.Fl c | e | f |
+.Fl n | u
 .Oc
 .Bk -words
 .Op Fl L Ar label
@@ -93,11 +98,12 @@ With
 the output format is modified slightly:
 the output begins with identification of the files involved and
 their creation dates and then each change is separated
-by a line with fifteen *'s.
+by a line with fifteen
+.Li * Ns 's .
 The lines removed from
 .Ar file1
 are marked with
-.Sq \-\ \& ;
+.Sq \&-\ \& ;
 those added to
 .Ar file2
 are marked
@@ -179,7 +185,8 @@ lines of context.
 Comparison options:
 .Bl -tag -width Ds
 .It Fl a
-Treat all files as ASCII.
+Treat all files as
+.Tn ASCII .
 .It Fl b
 Causes trailing blanks (spaces and tabs) to be ignored, and other
 strings of blanks to compare equal.
@@ -187,6 +194,18 @@ strings of blanks to compare equal.
 Try very hard to produce a diff as small as possible.
 This may consume a lot of processing power and memory when processing
 large files with many changes.
+.It Fl I Ar pattern
+Ignores changes, insertions, and deletions whose lines match the
+extended regular expression
+.Ar pattern .
+Multiple
+.Fl I
+patterns may be specified.
+All lines in the change must match some pattern for the change to be
+ignored.
+See
+.Xr re_format 7
+for more information on regular expression patterns.
 .It Fl i
 Ignores the case of letters.
 E.g.,
@@ -285,8 +304,9 @@ Binary files which differ,
 common subdirectories, and files which appear in only one directory
 are described as such.
 In directory mode only regular files and directories are compared.
-If a non-regular file such as a device special file or FIFO is
-encountered, a diagnostic message is printed.
+If a non-regular file such as a device special file or
+.Tn FIFO
+is encountered, a diagnostic message is printed.
 .Pp
 If only one of
 .Ar file1
@@ -372,11 +392,11 @@ Replace the range of specified lines with the line
 .Va ZZ .
 .It Li XX,YY Ns Ic c Ns Li ZZ,QQ
 Replace the range
-.Va XX , Ns YY
+.Va XX , Ns Va YY
 from
 .Ar file1
 with the range
-.Va ZZ , Ns QQ
+.Va ZZ , Ns Va QQ
 from
 .Ar file2 .
 .El
@@ -418,7 +438,7 @@ as the temporary directory.
 .El
 .Sh FILES
 .Bl -tag -width /tmp/diff.XXXXXXXX -compact
-.It Pa /tmp/diff.XXXXXXXX
+.It Pa /tmp/diff. Ns Ar XXXXXXXX
 Temporary file used when comparing a device or the standard input.
 Note that the temporary file is unlinked as soon as it is created
 so it will not show up in a directory listing.
@@ -442,7 +462,8 @@ An error occurred.
 .Xr diff3 1 ,
 .Xr ed 1 ,
 .Xr pr 1 ,
-.Xr fnmatch 3
+.Xr fnmatch 3 ,
+.Xr re_format 7
 .Sh STANDARDS
 The
 .Nm