C/C++中用libcurl进行http请求，向ES中插入数据

#include <stdio.h>
#include <curl/curl.h>

int Insert(long arg1, long arg2, long arg3, long arg4, const char* arg5)
{
    CURL *curl;
    CURLcode res;
    //const char* str = "{"time":"1542852001","total":"100","in":"20","out":"80","interface":"eth0"}";
    char str[100];
    char url[100] = "http://192.168.1.200:9200/index/type/";

    sprintf(str, "{"time":%ld,"total":%ld,"in":%ld,"out":%ld,"interface":"%s"}", arg1, arg2, arg3, arg4, arg5);
    
    curl_global_init(CURL_GLOBAL_ALL);
    curl = curl_easy_init();
    if(curl!=NULL)
    {
        curl_easy_setopt(curl, CURLOPT_URL, url);
        curl_easy_setopt(curl, CURLOPT_POSTFIELDS, str);
        res = curl_easy_perform(curl);
        if(res != CURLE_OK)
            //fprintf(stderr, "curl_easy_perform() failed: %s
", curl_easy_strerror(res));
            ErrPrintf("bandwidth error");
        curl_easy_cleanup(curl);
    }
    
    curl_global_cleanup();
    
    return 0;
}

注：
1) curl_global_init(CURL_GLOBAL_ALL);
在curl_easy_init函数调用时还没调用，它讲由libcurl库自动调用，所以多线程下最好主动调用该函数以防止在线程中curl_easy_init时多次调用。

2) curl_global_cleanup()
虽然libcurl是线程安全的，但curl_global_cleanup是不能保证线程安全的，所以不要在每个线程中都调用curl_global_init，应该将该函数的调用放在主线程中。

参考：
C++ 用libcurl库进行http通讯网络编程

curl库中curl_easy_setopt函数详解

官方例子

c/c++调用libcurl库发送http请求的两种基本用法