Re: [TUHS] Book Recommendation [ reallly inscrutable languages ]

Hi Alan (and others, should this move to COFF?) You just got yourself a big fan, anyone who had the insight to add includes and excludes to SCCS is a smart cookie, thank you for those, BitKeeper makes heavy use of them. You and me both. That sounds like BitKeeper's ChangeSet file. BitKeeper's model is repository based, a repository is a collection of SCCS files that are all managed as a unit. It doesn't work this way but you could think of the original content of the ChangeSet file as src/foo.c 1.1 man/foo.1 1.1 It is <pathname> <revision> The ChangeSet file is itself versioned so lets say you added a file, then version 1.2 of the ChangeSet file is src/foo.c 1.1 man/foo.1 1.1 examples/foo.eg 1.1 Because pathnames can change (BitKeeper has pathnames versioned just like the content is version) we had to come up with a non-changing name for pathnames (think inode # but it has to be globally unique). Ditto for revisions, they get changed all the time because of merges. BitKeeper's internal names look like (you can skip this for now): Inode: lm(a)lm.bitmover.com|man/WhatIs|19980710174007|58324|a9558aeac091a142 or user(a)host.domain|relative/path|date|chksum|64 bits of /dev/random Revision: lm(a)work.bitmover.com|man/WhatIs|20000205064107|58704 or same as the inode but skip the 64 bits. Getting back to useful stuff, you can clone a repository to any commit, all that does is check out that version of the ChangeSet file and strips off deltas until the tip matches the revision from that version of the ChangeSet file. BitKeeper was the first fully distributed SCM system, Git, Hg, et al, are all inspired by BitKeeper (and would have done well to copy it more closely, Git in particular is just awful). BitKeeper owes a tremendous nod to SCCS, SCCS taught me the value of that file format. --lm