I’m looking at migrating a large suite of IBM Assembler Language programs, from a vcs based on “filenames include version numbers”, to a modern vcs which will give me, among other things, the ability to branch and merge.
These files have 80-column records, the last 8 columns being an almost-meaningless sequence number.
For a number of reasons which I don’t really want to waste space by going into, I need the vcs to ignore (but hopefully preserve in some well-defined manner) the sequence number columns, and to diff and patch based only on the contents of the first 72 columns.
Any ideas?
Just to clarify “ignore but preserve”: I accept it’s a bit vague, as I haven’t fully collected my ideas yet.
It would be something along the lines of this:
“When merging/patching, if one side has sequence numbers, output them; if more-than-one side has sequence numbers, use those present in file (1|2|3)”
Why do I want to preserve sequence numbers? First, they really are sequence numbers. Second, I want to reintegrate this stuff back onto the mainframe, where sequence numbers can be terribly significant. (Those of you who know what “SMP/E” means will understand. Those who don’t, be happy, but tremble…)
I’ve just realised I hadn’t accepted an answer. Difficult choice, but @Noldorin comes closest to where I have to go.
I believe any modern version control system (Subversion and Bazaar are the ones I would typically recommend, being centralised and distributed respectively) can utilise an external diff/merge tool. Unfortunately, I would think you would have to write this custom merge tool yourself (at least I have never heard of one that does that you need), though this shouldn’t be a huge task I would imagine. Saying that, you may have some luck with the recommendations given in this StackOverflow question as well as this one. Sorry I can’t give any more information as to which ones you’ll want to look into in particular, but it’s worth having a browse through in case that any of them do happen to satisfy your requirements.