c回调函数

Green

1. 准备三个文件test.c, test.h, main.c
2. 编译生成so文件
3. 编译生成main
通过函数指针回调函数
test.h

#include <stdio.h>
void say_hello();
int caculate(int x, int y, int (*cacauFunc)(int x, int y));

test.c

#include "test.h"
void say_hello(char *name){
  printf("hello %s\n", name);
}
int caculate(int x, int y, int (*cacauFunc)(int x, int y)) {
  printf("receive x = %d, y = %d\n", x, y);
  return cacauFunc(x, y);
}

main.c

#include "test.h"
int add (int x, int y) {
  return x + y;
}
int sub (int x, int y) {
  return x - y;
}
void testSo() {
  say_hello("guanxianseng");
}
void test_call_func_pointer(){
  printf("start\n");
  int x = 5, y = 1, result = 0;
  result = caculate(x, y, add);
  printf("result = %d\n", result);
  result = caculate(x, y, sub);
  printf("result = %d\n", result);
}
int main(){
  test_call_func_pointer();
  return 0;
}

编译test.so

gcc test.c -fPIC -shared -o libtest.so

编译main

gcc main.c  -L. -ltest -o main

执行测试