redo-subst

[akrennmair]

I implemented a simple command redo-subst that helps with auto-generating lists of dependencies in certain cases. It takes two file suffixes and a list of file names, and generates a list of file names where the (matching) first suffix is substituted with the second suffix.

This allows constructs like these but in a more reliable fashion than ls ... | sed ...:

DEPS=`redo-subst .c .o foo/*.c`
redo-ifchange $DEPS
cc -o $3 $DEPS

This is also basically the first real Python code that I wrote in my life. If the code is too bad, feel free to correct me.

Best regards,
Andreas

[apenwarr]

Hmm, this looks reasonably nice, but I'm worried about adding commands that expand the redo API unnecessarily. What's "not reliable" about ls and sed?

BTW, I've learned a lot about sh since starting to work on redo. Nowadays what I would probably use is something like this:

DEPS=$(for d in foo/*.c; do echo "${d%.c}.o"; done)

...which is pretty easy, and doesn't require any forking, so it's faster than either ls/sed or your redo-subst.

So I appreciate the contribution, but I think it's best not to include it.

Thanks!