curl

最新推荐文章于 2021-09-02 13:58:12 发布

原创最新推荐文章于 2021-09-02 13:58:12 发布 · 781 阅读

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本文介绍了一个使用cURL库进行HTTP请求并获取网页内容的C++程序实例。该程序展示了如何设置cURL选项，包括URL设置、写回调函数、超时时间和HTTP头部等，并通过curl_easy_perform()执行请求。

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curl-7.21.7

#include <iostream>
#include <string.h>
#include "curl/curl.h"

using namespace std;
class CurlBuffer {
public:
    char *buffer_ptr_;
    size_t buffer_size_;

    CurlBuffer() {
      buffer_ptr_ = new char[204800];
      buffer_size_ = 0;
    }
    ~CurlBuffer() {
      delete buffer_ptr_;
    }
};

size_t WriteCallback(void *ptr, size_t size, size_t nmemb, void *data) {
CurlBuffer *buffer = (CurlBuffer *)data;
memcpy(buffer->buffer_ptr_+buffer->buffer_size_, ptr, size*nmemb);
buffer->buffer_size_ += size*nmemb;
buffer->buffer_ptr_[buffer->buffer_size_] = 0;
return size*nmemb;
}

int main (int argc, char *argv[]) {
CurlBuffer url_buffer_;
CURLcode curl_code_ = curl_global_init(CURL_GLOBAL_ALL);

if (curl_code_ != CURLE_OK) {
     return 1;
}
string url="http://www.baidu.com";

url_buffer_.buffer_size_ = 0;
CURLcode ret ;
CURL *curl = curl_easy_init();

if (curl) {
//    curl_easy_setopt(curl, CURLOPT_POST, 0);
    curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteCallback);
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *)&url_buffer_);
    curl_easy_setopt(curl, CURLOPT_TIMEOUT_MS, 15000);
    struct curl_slist *slist=NULL;
    slist = curl_slist_append(slist, "user-id:221666396");
    curl_easy_setopt(curl, CURLOPT_HTTPHEADER, slist);
    ret = curl_easy_perform(curl); //这是个阻塞函数，等都下载完了才往下执行
}
long response_code = 0;
ret = curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &response_code);
double download_size = 0;
ret = curl_easy_getinfo(curl, CURLINFO_SIZE_DOWNLOAD, &download_size);

curl_easy_cleanup(curl);
string json;
if (response_code==200 && download_size>0)
    json = string(url_buffer_.buffer_ptr_, url_buffer_.buffer_size_);
cout << "content:" << json;
curl_global_cleanup();
}