c语言：libevent接口直接与前端交互发送get/post

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>     //for getopt, fork
#include <string.h>     //for strcat
#include <sys/queue.h>
#include <event.h> //for http
#include <evhttp.h>
#include <signal.h>

void specific_handler(struct evhttp_request *req,void *arg)
{
    char debug[32] = "post data from c";
    //HTTP header
    evhttp_add_header(req->output_headers, "Server", MYHTTPD_SIGNATURE);
    evhttp_add_header(req->output_headers, "Content-Type", "text/plain; charset=UTF-8");
    evhttp_add_header(req->output_headers, "Connection", "close");
    //输出的内容
    struct evbuffer *buf;
    buf = evbuffer_new();
    evbuffer_add_printf(buf, "%s", debug);
    evhttp_send_reply(req, HTTP_OK, "OK", buf);

    char *post_data = EVBUFFER_DATA(req->input_buffer);
    evbuffer_free(buf);

}

//处理模块
void httpd_handler(struct evhttp_request *req, void *arg)
{
    //HTTP header
    evhttp_add_header(req->output_headers, "Server", MYHTTPD_SIGNATURE);
    evhttp_add_header(req->output_headers, "Content-Type", "text/plain; charset=UTF-8");
    evhttp_add_header(req->output_headers, "Connection", "close");
    //输出的内容
    struct evbuffer *buf;
    buf = evbuffer_new();
    evbuffer_add_printf(buf, "%s", data);
    evhttp_send_reply(req, HTTP_OK, "OK", buf);
    evbuffer_free(buf);

}

//当向进程发出SIGTERM/SIGHUP/SIGINT/SIGQUIT的时候，终止event的事件侦听循环
void signal_handler(int sig)
{
    switch (sig)
    {
        case SIGTERM:
        case SIGHUP:
        case SIGQUIT:
        case SIGINT:
        event_loopbreak();  //终止侦听event_dispatch()的事件侦听循环，执行之后的代码
        break;
    }
}

int n2n_front()
{
    //自定义信号处理函数
    signal(SIGHUP, signal_handler);
    signal(SIGTERM, signal_handler);
    signal(SIGINT, signal_handler);
    signal(SIGQUIT, signal_handler);

    //默认参数
    char *httpd_option_listen = "127.0.0.1";
    int httpd_option_port = 25536;
    int httpd_option_daemon = 0;
    int httpd_option_timeout = 120; //in seconds

    //判断是否设置了-d，以daemon运行
    if (httpd_option_daemon)
    {
        pid_t pid;
        pid = fork();
        if (pid < 0) {
            perror("fork failed");
            exit(EXIT_FAILURE);
        }
        if (pid > 0) {
          perror("fork failed");
            exit(EXIT_FAILURE);
        }
        if (pid > 0) {
            //生成子进程成功，退出父进程
            exit(EXIT_SUCCESS);
        }
    }
    /* 使用libevent创建HTTP Server */

    //初始化event API
    event_init();

    //创建一个http server
    struct evhttp *httpd;
    httpd = evhttp_start(httpd_option_listen, httpd_option_port);
    evhttp_set_timeout(httpd, httpd_option_timeout);

    //也可以为特定的URI指定callback
    evhttp_set_cb(httpd, "/about", specific_handler, NULL);
  //  evhttp_set_cb(httpd, "/zhuce", specific_handler2, NULL);

    //指定generic callback
    evhttp_set_gencb(httpd, httpd_handler, NULL);

    //循环处理events
    event_dispatch();

    evhttp_free(httpd);

    return 1;

}