rcsmerge(1) merge RCS revisions


rcsmerge [options] file


rcsmerge incorporates the changes between two revisions of an RCS file into the corresponding working file.

Filenames matching an RCS suffix denote RCS files; all others denote working files. Names are paired as explained in ci(1).

At least one revision must be specified with one of the options described below, usually -r. At most two revisions may be specified. If only one revision is specified, the latest revision on the default branch (normally the highest branch on the trunk) is assumed for the second revision. Revisions may be specified numerically or symbolically.

rcsmerge prints a warning if there are overlaps, and delimits the overlapping regions as explained in merge(1). The command is useful for incorporating changes into a checked-out revision.


Output conflicts using the -A style of diff3(1), if supported by diff3. This merges all changes leading from file2 to file3 into file1, and generates the most verbose output.
-E, -e
These options specify conflict styles that generate less information than -A. See diff3(1) for details. The default is -E. With -e, rcsmerge does not warn about conflicts.
Use subst style keyword substitution. See co(1) for details. For example, -kk -r1.1 -r1.2 ignores differences in keyword values when merging the changes from 1.1 to 1.2. It normally does not make sense to merge binary files as if they were text, so rcsmerge refuses to merge files if -kb expansion is used.
Send the result to standard output instead of overwriting the working file.
Run quietly; do not print diagnostics.
Merge with respect to revision rev. Here an empty rev stands for the latest revision on the default branch, normally the head.
This option has no effect; it is present for compatibility with other RCS commands.
Print RCS's version number.
Emulate RCS version n. See co(1) for details.
Use suffixes to characterize RCS files. See ci(1) for details.
Use zone as the time zone for keyword substitution. See co(1) for details.


Suppose you have released revision 2.8 of f.c. Assume furthermore that after you complete an unreleased revision 3.4, you receive updates to release 2.8 from someone else. To combine the updates to 2.8 and your changes between 2.8 and 3.4, put the updates to 2.8 into file f.c and execute

rcsmerge -p -r2.8 -r3.4 f.c >f.merged.c

Then examine f.merged.c. Alternatively, if you want to save the updates to 2.8 in the RCS file, check them in as revision and execute co -j:

ci -r2.8.1.1 f.c
co -r3.4 -j2.8: f.c

As another example, the following command undoes the changes between revision 2.4 and 2.8 in your currently checked out revision in f.c.

rcsmerge -r2.8 -r2.4 f.c

Note the order of the arguments, and that f.c will be overwritten.


Options prepended to the argument list, separated by spaces. A backslash escapes spaces within an option. The RCSINIT options are prepended to the argument lists of most RCS commands. Useful RCSINIT options include -q, -V, -x, and -z.
Normally, for speed, commands either memory map or copy into memory the RCS file if its size is less than the memory-limit, currently defaulting to ``unlimited''. Otherwise (or if the initially-tried speedy ways fail), the commands fall back to using standard i/o routines. You can adjust the memory limit by setting RCS_MEM_LIMIT to a numeric value lim (measured in kilobytes). An empty value is silently ignored. As a side effect, specifying RCS_MEM_LIMIT inhibits fall-back to slower routines.
Name of the temporary directory. If not set, the environment variables TMP and TEMP are inspected instead and the first value found is taken; if none of them are set, a host-dependent default is used, typically /tmp.


Exit status is 0 for no overlaps, 1 for some overlaps, 2 for trouble.


Author: Walter F. Tichy.
Manual Page Revision: 5.9.4; Release Date: 2015-06-21.
Copyright © 2010-2015 Thien-Thi Nguyen.
Copyright © 1990, 1991, 1992, 1993, 1994, 1995 Paul Eggert.
Copyright © 1982, 1988, 1989 Walter F. Tichy.