4. Intro to CVS commands

cvs provides a rich variety of commands (cvs_command in the Synopsis), each of which often has a wealth of options, to satisfy the many needs of source management in distributed environments. However, you don't have to master every detail to do useful work with cvs; in fact, five commands are sufficient to use (and contribute to) the source repository. The most commonly used CVS commands are checkout, update, add, remove, commit and diff.

4.1 checkout

cvs checkout modules... A necessary preliminary for most cvs work: creates your private copy of the source for modules (named collections of source; you can also use a path relative to the source repository here). You can work with this copy without interfering with others' work. At least one subdirectory level is always created.

bash$ cvs --help checkout
Usage:
  cvs checkout [-ANPRcflnps] [-r rev | -D date] [-d dir]
    [-j rev1] [-j rev2] [-k kopt] modules...
        -A      Reset any sticky tags/date/kopts.
        -N      Don't shorten module paths if -d specified.
        -P      Prune empty directories.
        -R      Process directories recursively.
        -c      "cat" the module database.
        -f      Force a head revision match if tag/date not found.
        -l      Local directory only, not recursive
        -n      Do not run module program (if any).
        -p      Check out files to standard output (avoids stickiness).
        -s      Like -c, but include module status.
        -r rev  Check out revision or tag. (implies -P) (is sticky)
        -D date Check out revisions as of date. (implies -P) (is sticky)
        -d dir  Check out into dir instead of module name.
        -k kopt Use RCS kopt -k option on checkout.
        -j rev  Merge in changes made between current revision and rev.
(Specify the --help global option for a list of other help options) 

4.2 update

cvs update Execute this command from within your private source directory when you wish to update your copies of source files from changes that other developers have made to the source in the repository.

bash$ cvs --help update
Usage: cvs update [-APdflRp] [-k kopt] [-r rev|-D date] [-j rev]
    [-I ign] [-W spec] [files...]
        -A      Reset any sticky tags/date/kopts.
        -P      Prune empty directories.
        -d      Build directories, like checkout does.
        -f      Force a head revision match if tag/date not found.
        -l      Local directory only, no recursion.
        -R      Process directories recursively.
        -p      Send updates to standard output (avoids stickiness).
        -k kopt Use RCS kopt -k option on checkout.
        -r rev  Update using specified revision/tag (is sticky).
        -D date Set date to update from (is sticky).
        -j rev  Merge in changes made between current revision and rev.
        -I ign  More files to ignore (! to reset).
        -W spec Wrappers specification line.
(Specify the --help global option for a list of other help options) 

4.3 add

cvs add file... Use this command to enroll new files in cvs records of your working directory. The files will be added to the repository the next time you run `cvs commit'. Note: You should use the `cvs import' command to bootstrap new sources into the source repository. `cvs add' is only used for new files to an already checked-out module.

bash$ cvs --help add
Usage: cvs add [-k rcs-kflag] [-m message] files...
        -k      Use "rcs-kflag" to add the file with the specified kflag.
        -m      Use "message" for the creation log.
(Specify the --help global option for a list of other help options)  

4.4 remove

cvs remove file... Use this command (after erasing any files listed) to declare that you wish to eliminate files from the repository. The removal does not affect others until you run `cvs commit'.

bash$ cvs --help remove
Usage: cvs remove [-flR] [files...]
        -f      Delete the file before removing it.
        -l      Process this directory only (not recursive).
        -R      Process directories recursively.
(Specify the --help global option for a list of other help options)

4.5 commit

cvs commit file... Use this command when you wish to ``publish'' your changes to other developers, by incorporating them in the source repository.

bash$ cvs --help commit
Usage: cvs commit [-nRlf] [-m msg | -F logfile] [-r rev] files...
        -n      Do not run the module program (if any).
        -R      Process directories recursively.
        -l      Local directory only (not recursive).
        -f      Force the file to be committed; disables recursion.
        -F file Read the log message from file.
        -m msg  Log message.
        -r rev  Commit to this branch or trunk revision.
(Specify the --help global option for a list of other help options)

4.6 diff

cvs diff file... Show differences between files in working directory and source repository, or between two revisions in source repository. (Does not change either reposi­ tory or working directory.)

bash$ cvs --help diff
Usage: cvs diff [-lNR] [rcsdiff-options]
    [[-r rev1 | -D date1] [-r rev2 | -D date2]] [files...]
        -l      Local directory only, not recursive
        -R      Process directories recursively.
        -D d1   Diff revision for date against working file.
        -D d2   Diff rev1/date1 against date2.
        -N      include diffs for added and removed files.
        -r rev1 Diff revision for rev1 against working file.
        -r rev2 Diff rev1/date1 against rev2.
        --ifdef=arg     Output diffs in ifdef format.
(consult the documentation for your diff program for rcsdiff-options.
The most popular is -c for context diffs but there are many more).
(Specify the --help global option for a list of other help options)

4.7 Emacs Editor

Emacs is a powerful editor and it supports CVS/RCS - especially for revision merging and comparing. Emacs main site is at http://www.emacs.org.