1、目录树
|-- app
| |-- Makefile
| `-- test.c
|-- Makefile
`-- mylib
|-- Makefile
|-- myadd.c
|-- myadd.h
|-- mysub.c
`-- mysub.h
2、静态库的创建
(1)app/Makefile
OBJS=test.o
INCLUDE_DIR=../mylib
CFLAGS += -I$(INCLUDE_DIR)
LDFLAGS += -L$(INCLUDE_DIR)
test : $(OBJS)
$(CC) $(CFLAGS) $(LDFLAGS) $^ -o $@ -lmy
.PHONY : clean
clean:
-rm *.o test
(2)app/test.c
#include <stdio.h>
#include "myadd.h"
#include "mysub.h"
int main()
{
int a=5,b=3;
printf("%d+%d=%d %d-%d=%d/n", a, b, myadd(a, b), a, b, mysub(a, b));
return 0;
}
(3)Makefile
CC = gcc
LD = ld
AR = ar
ARFLAGS = -cr
export CC LD AR ARFLAGS
SUBDIRS = mylib app
.PHONY : all
all:
@for subdir in $(SUBDIRS); /
do /
( cd $subdir && $(MAKE)) || exit 1; /
done
.PHONY : clean
clean:
@ for subdir in $(SUBDIRS); /
do /
(make clean -C $subdir); /
done
(4)mylib/Makefile
OBJS = myadd.o mysub.o
libmy.a : $(OBJS)
$(AR) $(ARFLAGS) $@ $^
%.o: %.c %.h
$(CC) -c tiny_mce_markerlt;
.PHONY : clean
clean:
-rm *.o *.a
【说明】tiny_mce_markerlt;改为$^时,会生成xxx.h.gch文件。将.h文件当成.c文件一样来编译就会生成.gch文件,这是gcc的预编译头技术,可以提高编译速度
(5)mylib/myadd.c
#include "myadd.h"
int myadd(int a, int b)
{
return a+b;
}
(6)mylib/myadd.h
#ifndef __MYADD_H__
#define __MYADD_H__
int myadd(int a, int b);
#endif
(7)mylib/mysub.c
#include "mysub.h"
int mysub(int a, int b)
{
return a-b;
}
(8)mylib/mysub.h
#ifndef __MYSUB_H__
#define __MYSUB_H__
int mysub(int a, int b);
#endif
3、动态库的创建
mylib/Makefile
OBJS = myadd.o mysub.o
libmy.so : $(OBJS)
gcc -shared -fPCI $^ -o $@
%.o: %.c %.h
$(CC) -c tiny_mce_markerlt;
.PHONY : clean
clean:
-rm *.o *.so
4、动态库的使用
$ ldd ./app/test
linux-gate.so.1 => (0x0085c000)
libmy.so => not found
libc.so.6 => /lib/libc.so.6 (0x00221000)
/lib/ld-linux.so.2 (0x00200000)
$ ./app/test
./app/test: error while loading shared libraries: libmy.so: cannot open shared object file: No such file or directory
$export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:./mylib
$ ldd ./app/test
linux-gate.so.1 => (0x00b29000)
libmy.so => ./mylib/libmy.so (0x00246000)
libc.so.6 => /lib/libc.so.6 (0x00248000)
/lib/ld-linux.so.2 (0x00200000)
$ ./app/test
5+3=8 5-3=2