makefile - 获取 Makefile 规则的文件扩展名

Question

如果我有以下规则

myfile.ext:
    ...
    # `extname $@` or something

如何从规则主体中引用扩展(在本例中为 ext)？

Answer 1

$(suffix)函数做你想做的事。

$(suffix names…)

Extracts the suffix of each file name in names. If the file name contains a period, the suffix is everything starting with the last period. Otherwise, the suffix is the empty string. This frequently means that the result will be empty when names is not, and if names contains multiple file names, the result may contain fewer file names.

For example,

$(suffix src/foo.c src-1.0/bar.c hacks)

produces the result ‘.c .c’.