使用纯Make实现的强大易用的解决方案:
override define \s :=
$() $()
endef
ifndef $(\s)
override $(\s) :=
else
$(error Defined special variable '$(\s)': reserved for internal use)
endif
override define dirname
$(patsubst %/,%,$(dir $(patsubst %/,%,$1)))
endef
override define prefix_1
$(if $(or $\
$(patsubst $(abspath $3)%,,$(abspath $1)),$\
$(patsubst $(abspath $3)%,,$(abspath $2))),$\
$(strip $(call prefix_1,$1,$2,$(call dirname,$3))),$\
$(strip $(abspath $3)))
endef
override define prefix
$(call prefix_1,$1,$2,$1)
endef
override define relpath_1
$(patsubst /%,%,$(subst $(\s),/,$(patsubst %,..,$(subst /,$(\s),$\
$(patsubst $3%,%,$(abspath $2)))))$\
$(patsubst $3%,%,$(abspath $1)))
endef
override define relpath
$(call relpath_1,$1,$2,$(call prefix,$1,$2))
endef
测试用例:
$(info $(call prefix,/home/user,/home/user))
$(info $(call prefix,/home/user,/home/user/))
$(info $(call prefix,/home/user/,/home/user))
$(info $(call prefix,/home/user/,/home/user/))
$(info $(call relpath,/home/user,/home/user))
$(info $(call relpath,/home/user,/home/user/))
$(info $(call relpath,/home/user/,/home/user))
$(info $(call relpath,/home/user/,/home/user/))
$(info ----------------------------------------------------------------------)
$(info $(call prefix,/home/user,/home/user/.local/share))
$(info $(call prefix,/home/user,/home/user/.local/share/))
$(info $(call prefix,/home/user/,/home/user/.local/share))
$(info $(call prefix,/home/user/,/home/user/.local/share/))
$(info $(call relpath,/home/user,/home/user/.local/share))
$(info $(call relpath,/home/user,/home/user/.local/share/))
$(info $(call relpath,/home/user/,/home/user/.local/share))
$(info $(call relpath,/home/user/,/home/user/.local/share/))
$(info ----------------------------------------------------------------------)
$(info $(call prefix,/home/user/.config,/home/user/.local/share))
$(info $(call prefix,/home/user/.config,/home/user/.local/share/))
$(info $(call prefix,/home/user/.config/,/home/user/.local/share))
$(info $(call prefix,/home/user/.config/,/home/user/.local/share/))
$(info $(call relpath,/home/user/.config,/home/user/.local/share))
$(info $(call relpath,/home/user/.config,/home/user/.local/share/))
$(info $(call relpath,/home/user/.config/,/home/user/.local/share))
$(info $(call relpath,/home/user/.config/,/home/user/.local/share/))
$(info ----------------------------------------------------------------------)
$(info $(call prefix,/home/user/.local/share,/home/user))
$(info $(call prefix,/home/user/.local/share,/home/user/))
$(info $(call prefix,/home/user/.local/share/,/home/user))
$(info $(call prefix,/home/user/.local/share/,/home/user/))
$(info $(call relpath,/home/user/.local/share,/home/user))
$(info $(call relpath,/home/user/.local/share,/home/user/))
$(info $(call relpath,/home/user/.local/share/,/home/user))
$(info $(call relpath,/home/user/.local/share/,/home/user/))
$(info ----------------------------------------------------------------------)
$(info $(call prefix,/home/user/.local/share,/home/user/.config))
$(info $(call prefix,/home/user/.local/share,/home/user/.config/))
$(info $(call prefix,/home/user/.local/share/,/home/user/.config))
$(info $(call prefix,/home/user/.local/share/,/home/user/.config/))
$(info $(call relpath,/home/user/.local/share,/home/user/.config))
$(info $(call relpath,/home/user/.local/share,/home/user/.config/))
$(info $(call relpath,/home/user/.local/share/,/home/user/.config))
$(info $(call relpath,/home/user/.local/share/,/home/user/.config/))
$(info ----------------------------------------------------------------------)
$(info $(call prefix,/root,/home/user))
$(info $(call prefix,/root,/home/user/))
$(info $(call prefix,/root/,/home/user))
$(info $(call prefix,/root/,/home/user/))
$(info $(call relpath,/root,/home/user))
$(info $(call relpath,/root,/home/user/))
$(info $(call relpath,/root/,/home/user))
$(info $(call relpath,/root/,/home/user/))
期望结果:
/home/user
/home/user
/home/user
/home/user
----------------------------------------------------------------------
/home/user
/home/user
/home/user
/home/user
../..
../..
../..
../..
----------------------------------------------------------------------
/home/user
/home/user
/home/user
/home/user
../../.config
../../.config
../../.config
../../.config
----------------------------------------------------------------------
/home/user
/home/user
/home/user
/home/user
.local/share
.local/share
.local/share
.local/share
----------------------------------------------------------------------
/home/user
/home/user
/home/user
/home/user
../.local/share
../.local/share
../.local/share
../.local/share
----------------------------------------------------------------------
../../root
../../root
../../root
../../root