Have you ever wished to have a time machine? Have you ever wished to travel back to 1988, to the time when 4.3BSD-Tahoe was the latest release and the SCCS deltas corresponding to it were the most recent deltas? Well, at least I do.

Although unfortunately real time travel is still limited to the X-Files, I have come up with a pretty good approximation, a time machine program. This program turns the Universe clock backwards on a given SCCS file, pruning it down to a given delta, specified either as an SID or as a delta serial number. The bulk of the work is done by the SCCS rmdel command. This command, however, can only delete one delta at a time and still leaves an audit trail in the delta table. My package consists of a shell script and two C programs that compensate these deficiencies. The result is that the SCCS file becomes byte-for-byte identical to the one that existed at the time you have chosen, just like with a real time machine!

You can download this package here as a compressed tarball. See the README file inside.

This version of tmachine is a little smarter than the previous version. It functions identically, but it issues a warning message when you delete invisible deltas (removed or branch deltas at the top of the delta table whose presence or absense doesn't affect the output from a trunk get). This reduces the possibility of making a mistake when SCCS-reconstructing sources.

@(#)tmachine.html 1.1 03/12/18

Michael Sokolov
msokolov@ivan.Harhan.ORG