C++使用curl下载文件（get请求）

article/2025/1/9 1:47:16

使用curl也可以下载文件，代码如下：

#include<iostream>
#include<string>
#include<curl\curl.h>
using namespace std;//下载文件数据接收函数
size_t dl_req_reply(void *buffer, size_t size, size_t nmemb, void *user_p)
{FILE *fp = (FILE *)user_p;size_t return_size = fwrite(buffer, size, nmemb, fp);//cout << (char *)buffer << endl;return return_size;
}//http GET请求文件下载  
CURLcode dl_curl_get_req(const std::string &url, std::string filename)
{//int len = filename.length();//char* file_name = new char(len + 1);//char*最后有一个结束字符\0//strcpy_s(file_name, len + 1, filename.c_str());const char* file_name = filename.c_str();char* pc = new char[1024];//足够长strcpy(pc, file_name);FILE *fp = fopen(pc, "wb");//curl初始化  CURL *curl = curl_easy_init();// curl返回值 CURLcode res;if (curl){//设置curl的请求头struct curl_slist* header_list = NULL;header_list = curl_slist_append(header_list, "User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; rv:11.0) like Gecko");curl_easy_setopt(curl, CURLOPT_HTTPHEADER, header_list);//不接收响应头数据0代表不接收 1代表接收curl_easy_setopt(curl, CURLOPT_HEADER, 0);//设置请求的URL地址 curl_easy_setopt(curl, CURLOPT_URL, url.c_str());//设置ssl验证curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, false);curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, false);//CURLOPT_VERBOSE的值为1时，会显示详细的调试信息curl_easy_setopt(curl, CURLOPT_VERBOSE, 0);curl_easy_setopt(curl, CURLOPT_READFUNCTION, NULL);//设置数据接收函数curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, &dl_req_reply);curl_easy_setopt(curl, CURLOPT_WRITEDATA, fp);curl_easy_setopt(curl, CURLOPT_NOSIGNAL, 1);//设置超时时间curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT, 6); // set transport and time out time  curl_easy_setopt(curl, CURLOPT_TIMEOUT, 6);// 开启请求  res = curl_easy_perform(curl);}// 释放curl curl_easy_cleanup(curl);//释放文件资源fclose(fp);return res;
}
int main()
{string dl_get_url = "http://httpbin.org/#/Images/get_image_jpeg";string filename ="1.jpeg";dl_curl_get_req(dl_get_url, filename);cout << "下载完成！" << endl;getchar();return 0;
}