Makefile中的字符串替换

SRC_DIRS := ./src
BUILD_DIR := ./build

SRCS := $(shell find $(SRC_DIRS) -name '*.cpp' -or -name '*.c' -or -name '*.s')
OBJS := $(SRCS:%=$(BUILD_DIR)/%.o)

TAR:
    @echo SRCS : $(SRCS)
    @echo OBJS : $(OBJS)

touch aa123zz.c
touch aa332dzz.cpp
touch aa44325drzz.cpp
make

SRCS : ./aa123zz.c ./aa44325drzz.cpp ./aa332dzz.cpp
OBJS : ./build/./aa123zz.c.o ./build/./aa44325drzz.cpp.o ./build/./aa332dzz.cpp.o

SRCS := ./aa123zz.c ./aa44325drzz.cpp ./aa332dzz.cpp
OBJS := $(SRCS:.cpp=.cxx)

TAR:
    @echo SRCS : $(SRCS)
    @echo OBJS : $(OBJS)

make
SRCS : ./aa123zz.c ./aa44325drzz.cpp ./aa332dzz.cpp
OBJS : ./aa123zz.c ./aa44325drzz.cxx ./aa332dzz.cxx

$(变量名:旧值=新值)

SRCS := ./aa123zz.c ./aa44325drzz.cpp ./aa332dzz.cpp
OBJS := $(SRCS:./aa%zz.cpp=./AA%%ZZ.cxx)

TAR:
	@echo SRCS : $(SRCS)
	@echo OBJS : $(OBJS)

make
SRCS : ./aa123zz.c ./aa44325drzz.cpp ./aa332dzz.cpp
OBJS : ./aa123zz.c ./AA44325dr%ZZ.cxx ./AA332d%ZZ.cxx

$(变量名:旧值带通配符）=新值带不带通配符都行通配符代表旧值中匹配的字符)