CVS Intro
Compiled by Michael Wang (xw73@columbia.edu)
Last updated 2007-02-23

* VCS Administration

** How to set up a repository?

  export CVSROOT=/some/dir/newrepos
  cvs init

One can use ``-d /some/dir/newrepos'' if the environment variable
is not set, but it is easier to set up CVSROOT once instead typing
the ``-d'' option over and over again.

** How to import a new project?

Goto the root of your new project, ie. myproj:

  cd myproj
  cvs import -m "initial import" myproj mycom start

Note:

- keep only those files you want to put under CVS control, and
  Clean out all other files from this directory;
- never put the ``repository'' under the dictory of your 
  new project; 

** How to set up write permission?

- Add a unix group and add writers to the group.
- cd /my/repository
- chgrp -R <group> .
- chmod ug+rwx . CVSROOT

See Fogel P98.

** How to set up remote CVS connection?

Use SSH

  export CVSROOT=:ext:<user>@<host>:<CVS_ROOT>
  export CVS_RSH=ssh

Or use the following procedure:

- Edit /etc/inetd.conf,

  cvspserver stream tcp nowait root /usr/local/bin/cvs cvs
  --allow-root=/my/repository pserver}

- Edit /etc/services,

  cvspserver 2401/tcp

- Setup $CVSROOT/CVSROOT/passwd in the format of:

  user:encripted passwd as in /etc/shadow

- Edit HUP the inetd process
 
  typeset -x CVSROOT=:pserver:<cvs server>:/my/repository

  on CVS client

- touch ~/.cvspass

- cvs login

* CVS Usage

** How to check out a working copy of the repository?

After import, you may check out a working copy of your project anywhere.

  cd /this/directory
  cvs checkout myproj

** How to check out a working copy of a new prog in the repository?

  cd /this/directory
  cvs checkout myproj/newdir/newprog

** How to find the difference

- between working copy and base copy,
- between working copy and repository copy,
- between base copy and repository copy, and
- between two versions in repository?

To find the difference between working copy and base copy
(last "checkout", "update" or "commit"),

  cvs diff <filename>

To find the difference between working copy and repository copy,

  cvs diff -r HEAD <filename>

To find the difference between base copy and repository copy,

  cvs diff -r BASE -r HEAD <filename>

To find the difference between two versions,

  cvs diff -c -r version1 -r version2 <filename>

Note: cvs diff also shares some options with GNU command line
diff, eg -c. 

** How do I ``update'' my copy with a repository copy?

By default, ``update'' will bring the updated version in repository 
to your working copy.

  cvs update filename

You can use ``update'' to dismiss the later modification
on your project, and revert to an earlier version. For example,
after using "cvs log" and "cvs diff", you decide
to get rid of current version 1.6, and change back to version 1.4,
you can use,

  cvs -Q update -p -r 1.4 filename > filename

Where -Q means quiet mode, however the noise goes to stderr
and will not be directed to a file. This option is not mandatory.
-p means to send the file content to standard output. 

If the filename is in a subdirectory which does not exist in your
working directory, use ``-d'' option,

  cvs update -d filename

This will bring over both the directory and the filename
under the directory.

** How do I commit a change?

After you modified a file and want to send the changes to repository, 
please use:

  cvs commit filenames

** How to check the status of a working copy?

  cvs status filenames

** How to finding out who did what (browsing log messages)?

  cvs log filenames

** How to add new files?

Two steps to add a new file to your repository: add and commit.

  cvs add new_files
  cvs commit -m "added new files" new_files

** How to add directorories?

One step to add new directories: add.

  mkdir newdir
  cvs add newdir
 
** How to removing files?

  rm oldfile
  cvs remove oldfile
  cvs commit -m "remove oldfile" oldfile

** How to removing directories?

  /* Suppose olddir with 2 files inside the directory
   * is the directory to be removed from repository.
   */

  cd olddir
  rm oldfile1 oldfile2
  cd ..
  cvs remove olddir     # scheduling olddir/oldfile[12] for removal
  cvs commit olddir     # remove these files permanently
  cvs update -P olddir  # remove empty dir from working dir

  /* 
   * cvs update -d olddir  # to bring back the empty dir
   */

  /* Alternatively:
   *
   * cd olddir
   * rm oldfile1 oldfile2
   * cvs remove oldfile1 oldfile2
   * cvs commit oldfile1 oldfile2  # have to remember the file names
   * cd ..
   * cvs update -P olddir
   */

** How to renaming files and directories?

  mv oldname newname
  cvs remove oldname
  cvs add newname
  cvs ci -m "mv old to new name" oldname newname

  mkdir newdir
  cvs add newdir
  mv olddir/oldfile1 olddir/oldfile2 newdir
  cd olddir
  cvs rm oldfile1 oldfile2
  cd ../newdir
  cvs add oldfile1 oldfile2
  cd ..
  cvs commit -m "mv old files to newdir"
  cvs update -P olddir newdir

References:

Bar, Moshe, and Karl Fogel, Open Source Development with CVS. 3rd ed.
Arizona: Paraglyph Press, 2003. <http://cvsbook.red-bean.com/OSDevWithCVS_3E.pdf>.