Remove prefix with make

问题:

Is there a way to remove a prefix from a string (a pathname in my case) in make?

As an example, suppose I had the string:

FILES = a/b/c.d a/b/e.f

I want to remove the a/, and be left with b/c.d b/e.f

I have tried using various combinations of dir, notdir and basename from the GNU make manual, but none seem to provide a nice solution.

$(dir $(FILE))      # a/b a/b
$(notdir $(FILE))   # c.d e.f
$(basename $(FILE)) # a/b/c a/b/e

The only way I've found to do this so far is:

$( join $(basename $(dir $(FILE))), $(notdir $(FILE)) )

Which is really ugly and long-winded. What I really need is some kind of $(removeprefix ...) function. Assuming that I know the prefix (a/) to be removed, can this be done with some kind of string manipulation?

回答1:

You can strip off a leading a/ with

$(FILE:a/%=%)

See the text substitution function reference for more options & details.

回答2:

Since you say GNU make, why not just:

$(FILE:a/%=%)

?