In a GNU Makefile (on an Ubuntu Linux system), how may I remove the filename suffix of each filename in a list in such a way that the filenames are truncated at the first dot?
Suppose I have
NAMES = file1.a.b.c file2.x.y.z file3.b file4.foo
where the names may come from a filename globbing expansion using $(wildcard file*).
I would like to end up with
NEWNAMES = file1 file2 file3 file4
or possibly even
NEWNAMES = file1.quux file2.quux file3.quux file4.quux
(not necessarily in this order)
The $(basename ...) function only strips the last suffix from the names.
In a shell supporting arrays, I would have used something like "${names[@]%%.*}" or "${names[@]/%.*/.quux}".
The reason for wanting to do this is that we're working with a bioinformatics environment where files have a known filename prefix, but their suffix may be any combination of .fa, .fas, .fasta (etc.), with the possibility of these suffixes doubling up (as in .fa.fa) and also having a file compressor suffix, such as .gz, at the end.
We would like to transform the filenames into normalised prefix.suffix filenames in the Makefile, regardless of how complex the initial filename suffix was.
If you want to do it with make functions without using a shell, you can use something like this:
NAMES := $(foreach F,$(wildcard file*),$(firstword $(subst ., ,$F)))