问题
I have this:
FOO = foo1 foo2 ... fooN
and want to get join all these string and separate it with, for instance, colong:
foo1:foo2:foo3:...:fooN
How to do this in GNU Make, without using external UNIX tools?
回答1:
See the code below.
# A literal space.
space :=
space +=
# Joins elements of the list in arg 2 with the given separator.
# 1. Element separator.
# 2. The list.
join-with = $(subst $(space),$1,$(strip $2))
Usage:
FOO = foo1 foo2 ... fooN
COLON_SEPARATED_FOO := $(call join-with,:,$(FOO))
回答2:
You can simply replace spaces with colon:
EMPTY :=
SPACE := $(EMPTY) $(EMPTY)
FOO = foo1 foo2 ... fooN
FOO_LIST = $(subst $(SPACE),:,$(FOO))
FOO_LIST is foo1:foo2:...:fooN.
来源：https://stackoverflow.com/questions/9551416/gnu-make-how-to-join-list-and-separate-it-with-separator