Quick Help to the most important CVS commands

For more informations see

• The CVS User Manual
• CVS Bubbles A site full of CVS specific information

Basic Idea:

• Source files are stored in a repository on the CVS server. The repository is organized like a directory tree (it actually is a tree of directories).
• The files are stored in a special format that keeps track of all the revisions of a file. Each revision of a file is identified by a number such as 1.10 or 1.11. Each time a changed version of a file is checked into the repository, the revision number is incremented.
• In order to work with the files, they have to be checked out into a work area. The work area is a local copy of the files. Modifications of the files can then be checked into the repository so that other users can use them.
• A group of source file revisions in the repository can be tagged i.e. identified by a symbolic name. This allows to create versions or releases of a group or all of the files.

In the following the most important basic CVS commands are explained:

1. Log into the CVS server

setenv CVSROOT :pserver:user@hepcvs.oeaw.ac.at:/data/cms/cvsroot
cvs login

user is your user name at hepcvs (ask Gerhard Walzel ( gerhard@hephy.oeaw.ac.at) for help if needed).

A valid password is required when logging in to the CVS server.

2. Check out all code from the CVS repository

Change to the directory under which the GMT structure should be created. The following commands will create a subdirectory 'GMT' containing the whole GMT tree below this directory.

cvs co -r tagname GMT

tagname is the tag (version) of the code and tools to check out. (e.g. GMTBoard_beh_works_14Nov2003)

To check out the latest version of all files (the 'CVS head'), the -r tagname option may be omitted.

3. Check out a single file

The cvs co command can also be used to check out a single file by changing to the directory of the file and typing:

cvs co -r revision_number_or_tagname FileName

revision_or_tagname is either a tag name or the revision number of a single file (e.g. 1.21).
4. Look at the log file of a single file

The log (or revision history) of a file can be displayed by changing to the directory of the file and typing:

cvs log FileName

5. Look at the difference of a file in the working area and in the repository

cvs diff -r revision_number_or_tagname FileName

The difference can also be displayed graphically using tkdiff.

tkdiff -Crevision_number FileName

If -Crevision_number is omitted, tkdiff compares the file in the work area to the latest version in the repository.
6. Check an updated version into the repository

cvs commit -m "comment on changes"  FileName

The new version will be checked in. The file revision number will be increased (e.g. from 1.10 to 1.11).
7. Add a new file to the repository

In the directory of the new file type:

cvs add FileName

This has to be done before committing a new file for the first time. The command also is used to add a new directory to the repository.
8. Tag a group of source files to create a version

Change to the directory containing the files to tag. All files in the repository residing in directories below will also be tagged. That will be tagged is the last version checked out or committed to the repository.

cvs tag tagname .

To tag the lasted checked out / committed version of everything:

cd GMT
cvs tag tagname .

tagname is a symbolic name like LogicFPGA_problemxy_fixed