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VCI::VCS::Cvs - Object-oriented interface to CVS


 use VCI;
 my $repository = VCI->connect(
    type => 'Cvs',
    repo => ''


This is a "driver" for VCI for the CVS (Concurrent Versioning System) version-control system. You can find out more about CVS at

For information on how to use VCI::VCS::Cvs, see VCI.


For CVS, the format of the repo argument to "connect" in VCI is the same as what you would put in the CVSROOT environment variable when using the cvs program.

The constructor also takes two additional, optional parameters:


The path to the "cvs" binary on your system. If not specified, we will search your PATH and throw an error if cvs isn't found.

Taint Mode: VCI will throw an error if this argument is tainted, because VCI just runs this command blindly, and we wouldn't want to run something like


The path to the "cvsps" binary on your system. If not specified, we will search your PATH and throw an error if cvsps isn't found.

Taint Mode: VCI will throw an error if this argument is tainted, because VCI just runs this command blindly, and we wouldn't want to run something like

Local Repositories

Though CVS itself doesn't allow relative paths in :local: roots, VCI::VCS::Cvs does. So :local:path/to/repo (or just path/to/repo) will be interpreted as meaning that you want the CVS repository in the directory path/to/repo.

In actuality, VCI::VCS::Cvs converts the relative path to an absolute path when creating the Repository object, so using relative paths will fail if you are in an environment where "abs_path" in Cwd fails.


In addition to the Perl modules listed for CVS Support when you install VCI, VCI::VCS::Cvs requires that the following things be installed on your system:


The cvs client program, at least version 1.11. You can get this at for *nix systems and for Windows systems.


This is a program that interacts with CVS to figure out what files were committed together, since CVS doesn't normally track that information, and VCI needs that information.

You can get it from (Windows users have to use Cygwin to run cvsps, which you can get from


cvsps groups file commits that are close together in time and have the same message into "PatchSets". Each of these PatchSets is given a unique, integer identifier.

Since VCI::VCS::Cvs uses cvsps, the revision identifiers on Commit objects will be these PatchSet ids.

These patchset ids are cached by cvsps in your home directory, so as long as you keep using VCI on the same system, the revision identifiers should stay stable. However, if you move VCI to a different system and don't copy the cvsps cache (usually in $HOME/.cvsps/) then the revision identifiers for Commits might change.

For File objects, the revision identifiers will be the actual revision identifier as returned by CVS for that file. For example 1.1, etc.

For Directory objects, the revision identifier is currently always HEAD.


  • Currently VCI doesn't understand the concept of "branches", so you are always dealing with the HEAD branch of a project. This will change in the future so that VCI can access branches of projects. If this feature is important to you, please let the author of VCI know so that he is encouraged to implement it more quickly.

  • cvsps needs to write to the HOME directory of the current user, you must have write access to that directory in order to interact with the History of a Project.

  • VCI::VCS::Cvs has to write files to your system's temporary directory (/tmp on *nix systems), and many operations will fail if it cannot. It uses the temporary directory returned by "tmpdir" in File::Spec.

  • If your program dies during execution, there is a chance that directories named like vci.cvs.XXXXXX will be left in your temporary directory. As long as no instance of VCI is currently running, it should be safe to delete these directories.

In addition, here are the limitations of specific modules compared to the general API specified in the VCI::Abstract modules:


get_project doesn't support modules yet, only directory names in the repository. Using a module name won't throw an error, but operations on that Project are likely to then fail.


CVS supports "root_project".


CVS doesn't track the history of a Directory, so Directory objects will never show up in the added, removed, modified, or contents of a Commit.


  • For the time accessor, we return the time of the most-recently-modified file in this directory. If there are no files in the directory, we return a time that corresponds to time() == 0 on your system, probably January 1, 1970 00:00:00. Currently this is a fairly slow operation, but it may be optimized in the future.

  • All Directory objects have a revision of HEAD, even if you get them through the parent accessor of a File.

  • If you manually create a Directory with a revision other than HEAD, the contents will be incorrect.


VCI::VCS::Cvs performs fairly well, although it may be slower on projects that have lots of files in one directory, or very long histories.

Working with a local repository will always be faster than working with a remote repository. For most operations, the latency between you and the repository is far more important than the bandwidth between you and the repository.




Max Kanat-Alexander <>


Copyright 2007-2010 by Everything Solved, Inc.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.