libcurl简单使用

1.发送请求获取数据

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <curl/curl.h>
 
#define LOGINSTATEURL "URL"
#define REFERERINDEX "Referer: referer url"
 
size_t call_back(void* buffer,size_t size,size_t nmemb,void *stream)
{
    char *buf = (char *)stream;
    strcpy(buf, (char*)buffer);
    return size*nmemb;
}
 
int main(int argc,char *argv[])
{
    int ret = 0;
    CURL *curl;
    CURLcode res;
    struct curl_slist *headers = NULL;
    char buf[2048] = "";
    curl = curl_easy_init();
    if (!curl)
    {
        sfw_printf("Failed init login curl
");
        return 0;
    }
    headers = curl_slist_append(headers,REFERERINDEX);
    curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
    curl_easy_setopt(curl,CURLOPT_URL,LOGINSTATEURL);
    curl_easy_setopt(curl,CURLOPT_POSTFIELDS,""); 
        
    curl_easy_setopt(curl,CURLOPT_WRITEFUNCTION,call_back);
    curl_easy_setopt(curl,CURLOPT_WRITEDATA,&buf); 
        
    curl_easy_setopt(curl,CURLOPT_POST,1); 
    //curl_easy_setopt(curl,CURLOPT_VERBOSE,1); //打印调试信息
    //curl_easy_setopt(curl,CURLOPT_HEADER,0); //将响应头信息和相应体一起传给call_back
    curl_easy_setopt(curl,CURLOPT_FOLLOWLOCATION,1); //设置为非0,响应头信息location
    //curl_easy_setopt(curl,CURLOPT_COOKIEFILE,"/tmp/cookie");//从文件读取cookie
    curl_easy_setopt(curl,CURLOPT_COOKIE,"cookie str");
 
    res = curl_easy_perform(curl);
    if (res != CURLE_OK)
    {
        switch(res)
        {
            case CURLE_UNSUPPORTED_PROTOCOL:
                fprintf(stderr,"不支持的协议,由URL的头部指定
");
            case CURLE_COULDNT_CONNECT:
                fprintf(stderr,"不能连接到remote主机或者代理
");
            case CURLE_HTTP_RETURNED_ERROR:
                fprintf(stderr,"http返回错误
");
            case CURLE_READ_ERROR:
                fprintf(stderr,"读本地文件错误
");
            default:
                fprintf(stderr,"返回值:%d
",res);
        }
        return -1;
    }

    const char *success_str = ""success":true";
    char *success = strstr(buf, success_str);
    if (NULL != success)
    {
        ret=1;
    } 
    else
    {
        ret=0;
    }
    curl_slist_free_all(headers);
    curl_easy_cleanup(curl);
    return ret;76 }