CVS Repository Creation

How to set up a personal CVS repository

1. Set the CVS_RSH variable to 'ssh':

   setenv CVS_RSH ssh

2. Determine where you want you cvs repository to live. For example, you might want it to live in /student/abc123/mycvs (where abc123 is replaced with your own NSID, of course).
3. Initialize the repository with:

   cvs -d somemachine:/student/abc123/mycvs/root init

   where somemachine is replaced with the name of any computer that you can login to and where /student/abc123 is available (e.g. any of the stealth machines.
4. Now that the repository is set up, the next step is to add a project (or 'module') to the repository. Here we consider adding a project called cribbage which happens to live in a directory called cribbage, and which consists of the following files:

   total 47
-rw-r--r-- 1 abc123 student 104 Dec 12 08:56 Makefile
-rw-r--r-- 1 abc123 student 608 Dec 12 08:56 README
-rw-r--r-- 1 abc123 student 45352 Dec 12 08:56 cribbage.c


   The correct way to import this project is to do the following two commands:

   cd ..../cribbage
cvs -d somemachine:/student/abc123/mycvs/root import -m "Initial import of my cribbage project" cribbage vtag rtag


   This will create a module called cribbage. It is not necessary to have all (or any!) project files present when a module is created. It is sufficient to only have the main project directory. For example:

   mkdir myproject cd myproject
cvs -d somemachine:/student/abc123/mycvs/root import -m "Initial import of myproject" myproject vtag rtag

   is all that is needed to make an empty project named myproject.
5. Now that the project exists in the repository it can be "checked out" to any location. E.g.

   cvs -d stealth10:/student/abc123/mycvs/root checkout cribbage

6. Once a project has been checked out you can then proceed to make changes to the checked-out copy. To add a file called TODO to the cribbage repository:

   cd cribbage
cp /student/abc123/TODO .
cvs add TODO
cvs commit -m "Initial commit" TODO

   If you have a line that contains the string:

   $Id$

   anywhere in your file, then that string will get expanded to something like:

   $Id: TODO,v 1.1 2006/11/29 11:16:58 abc123 Exp $

   after the initial import. Each time you check-in or check-out a revision, the version of the file will be displayed in this line.

   When doing the cvs commit, the -m "Initial commit" is the message to associate with the commit. If you don't specify this, then your favorite editor will be fired up, and you'll be asked to provide a comment on the changes being checked in.

7. You are not limited to a single checkout -- all or part of a particular project can be checked out. E.g.:

   cd /tmp
cvs -d stealth10:/student/abc123/mycvs/root co cribbage

   Note that this pulls out the entire contents of the module 'cribbage'. If we just wanted the one file, we could do:

   cvs -d stealth10:/student/abc123/mycvs/root co cribbage/TODO

   Once you are working inside the module directory (where CVS directories exist) there is no need to specify the repository being used.
8. Edit the file and check it back in:

   cd cribbage
vi TODO
# make some changes
cvs ci TODO # (or 'cvs commit TODO')

   observe that the $Id$ line is now something like:

   $Id: TODO,v 1.2 2006/11/29 11:23:19 abc123 Exp $

9. If you're collaborating on a project with others, you will need to update your local files to incorporate any of the changes others have made. This command is run inside the already checked-out project directory:

   cvs -d stealth10:/student/abc123/mycvs/root -q update -dPA

   The '-q' says to do this job quietly, and the '-dPA' is needed to make sure that new directories and removed files/directories get dealt with correctly.
10. Other useful commands:

    cvs history scan.pl # see who's changed the file recently.
cvs annotate scan.pl # see who modified what lines, and when.
# Also known as 'cvs blame' in some circles :)

# show a regular 'diff' between revisions 1.1 and 1.2
cvs diff -r 1.1 -r 1.2 scan.pl

# show a context 'diff' between revisions 1.1 and 1.2
cvs diff -c -r 1.1 -r 1.2 scan.pl


11. One can also get fancy and add tags, branches, and a bunch of other things. See 'man cvs' for more information, and/or consult your favorite web-resource for more information on cvs.

How to create a shared CVS repository

1. There are a couple of ways to share a repository. Both ways require all repository users to be in the same Unix group.
   1. Use ``security by obscurity'' and rely on a hidden directory whos name is known only to the members of the group.
   2. Ask your friendly neighbourhood techstaff member for a special group.
   In the first case, the procedure is to create a hidden directory for the repository. For example:

   mkdir /student/abc123/hidden
chmod 711 /student/abc123/hidden
mkdir /student/abc123/hidden/abcd1234
chgrp student /student/abc123/hidden/abcd1234
chmod 770 /student/abc123/hidden/abcd1234
chmod g+s /student/abc123/hidden/abcd1234

   Note that these directories will be created with your default group and that you will want to chgrp them to a group that all users share (e.g. student). As well, the only ``security'' here is that only users who know the full path to the repository will be able to read or modify the files. The repository path will then be somemachine:/student/abc123/hidden/abcd1234.

   In the second case, you will be assigned a group name similar to stgr0001. The setup for the directories can be simply:

   mkdir /student/abc123/mycvs
chgrp stgr0001 /student/abc123/mycvs
chmod 770 /student/abc123/mycvs
chmod g+s /student/abc123/mycvs

   and the repository path will be just somemachine:/student/abc123/mycvs.
2. Initialization of the repository is done as in the previous section with the cvs init command.
3. Setup directory permissions according to who will be using the repository. For example, if members of group stgr0001 are to have access to the repository, then perform the following:

   chgrp -R stgr0001 /student/abc123/mycvs/root
find /student/abc123/mycvs/root -type d -exec chmod g+s {} \;

   This will allow anyone in group stgr0001 to access and change files in the repository.
4. Following the previous example, after the initial import of the module cribbage, it will likely be necessary to make sure that the permissions on the new module are set properly. For group stgr0001 the following lines would take care of this:

   chgrp -R stgr0001 /student/abc123/mycvs/root/cribbage
chmod g+s /student/abc123/mycvs/root/cribbage

5. At this point all the normal cvs commands will work for all members who have group permissions no the repository.