在main函数执行之前和执行之后执行的方法

//

// before&after.c

// Created by labuser on 10/30/11.

// Copyright (c) 2011 __MyCompanyName__. All rights reserved.

//

#include <stdio.h>

void before() __attribute__((constructor));

void after() __attribute__((destructor));

void before() {

//printf("This is function %s\n", __func__);

fprintf(stdout, "In %s %d\n", __func__, __LINE__);

}

void after() {

//printf("This is function %s\n", __func__);

fprintf(stdout, "In %s %d\n", __func__, __LINE__);

}

int main(int argc, char* argv[]) {

atexit(after);

printf("This is function %s\n", __func__);

return 0;

}