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Copyright © 2013 Keith Packard, Bart Massey and Eric Raymond

You may want to look at, which contains Eric Raymond's currently-maintained version of cvs-fast-export. Probably this GitHub repo should be backed off to before Eric's changes, when it was the latest known version of parsecvs.

This is the former canonical repo for git cvs-fast-export, formerly parsecvs. This tool does what its new name implies: exports cvs repositories in a format suitable for git fast-import.

This tool is currently being maintained by Eric Raymond, who has rewritten parts of it to support current git in a more sensible way.

Below are a bunch of stale notes and old versions of README material, preserved for historical reasons. You might just want to ignore them.

Bart Massey

Note: The standalone code currently finally did not run properly in at least some instances. It is suspected that this was due to changes in libgit that hadn't been tracked in the parsecvs code. Fortunately, Eric Raymond's changes to support git fast-import mooted that problem.

Note: Building parsecvs formerly required a copy of libgit and its header files to be on your system. For my Debian system, that meant pulling the Git source and building it. The Makefile variable GITDIR should be aimed at an appropriate location if you ever try to build old code.

This is the current canonical repo for parsecvs. It merges three different Git repos:

  • The latest copy I could find of Keith Packard's original repo.
  • Kristian Hogsberg's repo from This was a fast-forward merge.
  • Ivan Zakharyaschev's repo from This had two merge conflicts, which I hope I resolved in sensible ways.

I will commit (no pun intended) to maintaining this version as the "one true branch" on github going forward. I will not actively look for patches, but if people send them to me I will look at getting them in. Further, if it breaks for me, I will fix it and push my patches here.

I was in on the original design of parsecvs, and have gotten a lot of use out of it over the years. Hopefully it will remain useful for years to come.

Bart Massey

Here is the original parsecvs README. Much of this information is out-of-date as of 2013, but I preserve it in case it might be useful.

                                  April, 2006

    This directory contains code which can directly read RCS ,v files and
    generate a git-style rev-list structure from them. Revision lists can be
    merged together to produce a composite revision history for an arbitrary
    collection of files.

    Optional behaviors are controlled by editing the source and recompiling.

    If arguments are supplied, `parsecvs` assumes they're all ,v files and reads
    them in. If no arguments are supplied, `parsecvs` reads filenames from stdin,
    one per line.

    Working features:

            Attic support. Files found in the Attic are not dealt with specially
            at all; they should be renamed in the output, and the terminal
            revision noted so that they don't appear in later revision. I think
            fixing this will be reasonably straightforward.

            Disjoint branch resolution. Branches occurring in a subset of the
            files are not correctly resolved; instead, an entirely disjoint
            history will be created containing the branch revisions and all
            parents back to the root. I'm not sure how to fix this; it seems
            to implicitly assume there will be only a single place to attach as
            branch parent, which may not be the case. In any case, the right
            revision will have a superset of the revisions present in the
            original branch parent; perhaps that will suffice.

            Connection to git. As mentioned above, the code doesn't actually
            connect to git yet, so while it can generate lovely graphs, it won't
            do anything useful. I think this is reasonably straight forward as
            well; we've got a revision history containing the necessary version
            of every file at each point in time. This could either be done by
            emitting git commands and sending them to a shell, or by linking
            against a git library and doing everything internally.

            Author translation. Just as git cvsimport does.

    Missing features:

            Reasonable command line syntax. The current lack of command line
            parsing should be fixed to align with the usual git tools.

            Testing. I'm sure there are plenty of additional bugs to be found;
            I've tested with valgrind and eliminated memory leaks and other