BASH Expression to replace beginning and ending of a string in one operation?
- by swestrup
Here's a simple problem that's been bugging me for some time. I often find I have a number of input files in some directory, and I want to construct output file names by replacing beginning and ending portions. For example, given this:
source/foo.c
source/bar.c
source/foo_bar.c
I often end up writing BASH expressions like:
for f in source/*.c; do
a="obj/${f##*/}"
b="${a%.*}.obj"
process "$f" "$b"
done
to generate the commands
process "source/foo.c" "obj/foo.obj"
process "source/bar.c "obj/bar.obj"
process "source/foo_bar.c "obj/foo_bar.obj"
The above works, but its a lot wordier than I like, and I would prefer to avoid the temporary variables. Ideally there would be some command that could replace the beginning and ends of a string in one shot, so that I could just write something like:
for f in source/*.c; do process "$f" "obj/${f##*/%.*}.obj"; done
Of course, the above doesn't work. Does anyone know something that will? I'm just trying to save myself some typing here.
