把.o文件放入指定目录的Makefile

TARGET = a.exe
SRCEXT = c
OBJDIR = o
CC = gcc
CFLAGS = -DHAVE_CONFIG_H -DGAWK -DNDEBUG -I. -g # -Os

SRCS = $(wildcard *.$(SRCEXT))
OBJS = $(patsubst %.$(SRCEXT), $(OBJDIR)/%.o, $(SRCS))
# $(patsubst pattern, replacement, text) pattern substitute

$(TARGET) : $(OBJS) # $^ 所有
	$(CC) -o $@ $^

$(OBJDIR)/%.o : ./%.$(SRCEXT) # $< 第一个
	$(CC) $(CFLAGS) -c -o $@ $<

clean: # 用@打头则不echo要执行的命令，-忽略命令的exit值
	@-rm -f $(OBJS)

dep:
	$(CC) $(CFLAGS) -MM $(SRCS) >.dep

wtf: # What the fuck (什么鬼)
	@echo SRCS = $(SRCS)
	@echo OBJS = $(OBJS)
	@echo $(wildcard *.sh)

-include .dep # -使得当.dep不存在时不报错

# https://www.cnblogs.com/haoxing990/p/4629454.html
# https://www.cnblogs.com/guolongnv/articles/8728353.html
# https://www.cnblogs.com/geeker/p/4455538.html
# https://blog.csdn.net/qinglongqishi1/article/details/80419332