CVS, or the Concurrent Versioning System, allows groups of people (mostly developers) the ability to maintain and document changes in code for shared projects.

If you don’t have time to read the large, but well written CVS Admin Manual, and aren’t jumping on the Subversion bandwagon quite yet, try these simple steps to get going in cvs securely over ssh:

1. First, set up all the user ssh accounts, if they are not added already.
2. Now, lets add the directory (as root, of course) for our cvs repository:
   

   mkdir /w/cvs
chmod 2770 /w/cvs

3. Add the cvs group and give that dir to them:
   

   groupadd cvs
chown root:cvs /w/cvs
cvs -d /w/cvs init


4. We will need to set the CVS_UMASK for each user as such in the shell of the remote machine they’ll be using CVS from, and set the CVS_RSH to ssh :
   

   export CVS_UMASK=002
export CVS_RSH=ssh

   Now Set the CVSROOT:

   export CVSROOT=:ext:username@hostname:/w/cvs

5. If desirable, research ssh-agent/ssh-keygen and use keys for passwordless authentication.
6. That’s it! Lets add a project:
   

   cd /home/user/someproject
cvs -d /w/cvs import -m "New Project Import" project someproject release

   The -m will add the “New Project Import” as a comment to your action. You can view these by doing this:

   cvs -l somefile

I’ve used cvs for a number of years. Here are some tips that I wish someone would have told me when I started:

• cvs update on a regular basis. Do it before you start working on ANYTHING. It will save you the headache of merging code at some point.
• Leave accurate log comments. You will need them down the road, when you don’t remember what you were thinking when you changed some bit of code.
• Double-check your permissions on the cvs directories. You don’t need those getting messed up by a user who doesn’t know what he/she is doing.
• Make sure backups are happening. You should be backing your repository every night.
• Make sure the disk doesn’t fill up! Repositories can get big in a hurry.
• Want to view your repository over the web? Check out viewcvs or cvsweb.