Libevent基本应用实例--专为懒人定制

本段代码不保证可编译，甚至不保证正确性，仅仅给出使用的简单示例，懒人各取所需：

#define MAX_ARG_LENGTH 1024/** *  Http server callback  */void http_handle(struct evhttp_request *request,void *data){    if( EVHTTP_REQ_GET == request->type){        (char*)data = strdup(request->uri);    }    if( EVHTTP_REQ_POST == request->type){        size_t size = EVBUFFER_LENGTH(request->input_buffer);        if(size > 0){            memcpy((char*)data, EVBUFFER_DATA(request->input_buffer),size);        }    }    struct evkeyvalq *param;    evhttp_parse_query(uri, param);    const char *user = evhttp_find_header(param, "user");    const char *information = evhttp_find_header(param, "information");        // do something with the information like parse to JSON and so on.        struct evbuffer *response = evbuffer_new();    evhttp_add_header(req->output_headers, "Content-Type", "text/plain");    evhttp_add_header(req->output_headers, "Connection", "keep-alive");    evhttp_add_header(req->output_headers, "Cache-Control", "no-cache");     evhttp_add_header(req->output_headers, "author", "zhousy");    evbuffer_add_printf(response,"information=%s",information);    evhttp_send_reply(req, HTTP_OK, "OK", response);    // evhttp_send_reply(req, HTTP_BADREQUEST, "BAD request", response);        evhttp_clear_headers(param);    evbuffer_free(response);}/** * Http client callback */void client_handler(struct evhttp_request request, void *data){     //const char *content_length = evhttp_find_header(request->input_headers, "Content-Length");     size_t size = EVBUFFER_LENGTH(request->input_buffer);     if(size > 0){        const char *content =  EVBUFFER_DATA(request->input_buffer);     }     evhttp_connection_free((evhttp_connection*)data);}int main(int argc, char* argv[]){        struct event_base *base;    struct evhttp *http;    struct event *timer_event;    struct event *IO_event;    struct event *SIG_event;    char *ip = argv[1];    int port = atoi(argv[2]);    char *data[MAX_ARG_LENGTH];    base = event_base_new();    http = evhttp_new(base);    if( -1 == evhttp_bind_socket(http, ip , port)){        exit(1);    }    else{        evhttp_set_gencb(http, http_handle, (void*)data);    }    evhttp_set_timeout(http,120);    /**     * This is the sample show how to add timer event using Libevent     */    struct timeval timeout;    timeout.tv_sec = 1;    timeout.tv_usec = 10;    evtimer_set(timer_event, timer_event_handler, (void*)data);    event_base_set(base, timer_event);    evtimer_add(timer_event, &timeout);    /**     * This is the sample show how to add IO event using Libevent     */    //int file = open(argv[3],O_RDWR | O_CREATE | O_TRUNC, S_IRWXU|S_IWGRP|S_IROTH);    //fcntl(file,F_SETFL,O_NONBLOCK);    int socket = socket(AF_INET, SOCK_STREAM, 0);    struct sockaddr_in addr;    addr.sin_family = AF_INET;    addr.sin_addr.s_addr = hton(inet_aton("127.0.0.1"));    addr.sin_port = htons(80);    if(connect( socket,(sockaddr*) &addr, sizeof(addr)) < 0){        exit(1);    }    event_set(IO_event, socket, EV_READ | EV_PERSIST, IO_event_handler, (void*)data);    event_base_set(base,IO_event);    event_add(IO_event,NULL);    /**     * This is the sample show how to add signal event using Libevent     */    //SIG_event = evsignal_new(base, SIGUSR1, SIG_event_handler,NULL);    //evsignal_add(SIG_event,NULL);    //signal_set(SIG_event, SIGCHLD, SIG_event_handler, (void*)data);    evsignal_set(SIG_event, SIGCHLD, SIG_event_handler, (void*)data);    event_base_set(base,SIG_event);    while(true){        struct timeval run_interval_time;        run_interval_time.tv_sec = 0;        run_interval_time.tv_usec = 1000;        event_base_loopexit(base,&run_interval_time);        event_base_dispatch(base);        // do something else when exit from dispatch;    }       /**     *  This is the sample show how to build client request using Libevent     *      */    struct evhttp_connection *client;    struct evhttp_request *request;    client = evhttp_connection_new("127.0.0.1",80);    if(client){        evhttp_connection_set_base(base,client);        //set connection timeout        evhttp_connection_set_timeout(client, 5);        //set response handler              request =  evhttp_request_new(client_handler, (void*)client);        //set request headers        evhttp_add_header(request->output_headers, "Host", "127.0.0.1");        evhttp_add_header(request->output_headers, "Content-Length", "0");        //set request type and send request        evhttp_make_request(client, request,EVHTTP_REQ_GET, request_str->str);    }    evtimer_del(timer_event);    signal_del(SIG_event);    evhttp_free(http);    event_base_free(base);}