cvs-fast-export tries to group the per-file commits and tags in a RCS file collection or CVS project repository into per-project changeset commits with common metadata, in the style of Subversion and later version-control systems.

If arguments are supplied, the program assumes they’re all ,v files and reads them in. If no arguments are supplied, the program reads filenames from stdin, one per line. Directories are skipped.

Files from either Unix CVS or CVS-NT are handled. If a collection of files has commit-id fields, changesets will be constructed reliably using those.

In the default mode, which generates a git-style fast-export stream to standard output:

The prefix given using the -s option or, if the option is omitted, the longest common prefix of the paths is discarded from each path.
Files in CVS Attic and RCS directories are treated as though the "Attic/" or "RCS/" portion of the path were absent. This usually restores the history of files that were deleted.
Permissions on fileops related to a file will be controlled by the permissions on the corresponding master. If the executable bit on the master is on, all fileops will have 100755 permissions; otherwise 100644.
Each patchset in the collection of files becomes a commit.
CVS tags become git lightweight tags.
The HEAD branch is renamed to master.
Other tag and branch names are sanitized to be legal for git; the characters ~^\*? are removed.
Since .cvsignore files have a syntax upward-compatible with that of .gitignore files, they’re renamed.