.\"	$OpenBSD: rcsdiff.1,v 1.27 2007/05/31 19:20:15 jmc Exp $
.\"
.\" Copyright (c) 2005 Joris Vink <joris@openbsd.org>
.\" All rights reserved.
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.Dd $Mdocdate: May 31 2007 $
.Dt RCSDIFF 1
.Os
.Sh NAME
.Nm rcsdiff
.Nd compare RCS revisions
.Sh SYNOPSIS
.Nm
.Op Fl cnquV
.Op Fl k Ns Ar mode
.Op Fl r Ns Ar rev
.Op Fl x Ns Ar suffixes
.Op Fl z Ns Ar tz
.Op Ar diff_options
.Ar
.Sh DESCRIPTION
The
.Nm
program is used to compare revisions of RCS files,
in much the same way as the
.Xr diff 1
utility.
Differences between two specific revisions can be requested,
as well as differences between the current working file and
the latest revision of the default branch.
.Pp
It is not possible to display differences between entire directories,
or differences between more than two files.
All diffs produced are in the standard diff format,
unless the
.Fl u
option is specified,
which produces unified diffs.
.Pp
.Nm
also supports
keyword substitution \(en
see the
.Xr rcs 1
man page for more information.
.Pp
The following options are supported:
.Bl -tag -width Ds
.It Fl c
Produces a diff with three lines of context.
See
.Xr diff 1
for more information.
.It Fl k Ns Ar mode
Specify the keyword substitution mode.
.It Fl n
Produces a diff in the same format that is used in the RCS files.
.It Fl q
Be quiet about reporting.
.It Fl r Ns Ar rev
Produces a diff with respect to revision
.Ar rev .
This option should be specified twice to generate a diff
between two specific revisions.
If only one revision is specified,
diffing is done between that revision and
the latest revision of the default branch.
.It Fl u
Produces a unified diff with three lines of context.
See
.Xr diff 1
for more information.
.It Fl V
Print RCS's version number.
.It Fl x Ns Ar suffixes
Specifies the suffixes for RCS files.
Suffixes should be separated by the
.Sq /
character.
.It Fl z Ns Ar tz
Specify the date output format.
.It Ar diff_options
Any of the options documented in
.Xr diff 1
may also be specified.
.El
.Sh ENVIRONMENT
.Bl -tag -width RCSINIT
.It Ev RCSINIT
If set, this variable should contain a list of space-delimited options that
are prepended to the argument list.
.It Ev TMPDIR
When set, this variable specifies the directory where temporary files
are to be created.
The default is set to
.Pa /tmp .
.El
.Sh EXAMPLES
Compare the latest revision of the default branch with the content of
working file
.Pa foo.c :
.Pp
.Dl $ rcsdiff foo.c
.Pp
Compare revision 1.7 and 1.8 of file
.Pa foo.c
and ignore differences in keyword values:
.Pp
.Dl $ rcsdiff -kk -r1.7 -r1.8 foo.c
.Sh DIAGNOSTICS
The
.Nm
utility exits with one of the following values:
.Pp
.Bl -tag -width Ds -compact -offset indent
.It 0
No differences were found.
.It 1
Differences were found.
.It 2
An error occurred.
.El
.Sh SEE ALSO
.Xr ci 1 ,
.Xr co 1 ,
.Xr diff 1 ,
.Xr ident 1 ,
.Xr rcs 1 ,
.Xr rcsclean 1 ,
.Xr rcsmerge 1 ,
.Xr rlog 1
.Sh STANDARDS
The flag
.Op Fl T
has no effect and is provided
for compatibility only.