C + + uses the Libcurl library to send HTTP requests (get and post can be used to request HTML information or to request XML and JSON strings)

C + + to implement an HTTP network connection, the need for third-party libraries, libcurl use is still very convenient

Environment: Win32 + VS2015

If you want to use it under Linux, it's basically the same

1, download compile Libcurl

Download the curl source, find the VS project, follow the x86 x64 and compile the static lib with the corresponding debug and release

2, building the project

1) Curl header file and Lib Copy to project directory

2) Configure the Lib directory in the Include and additional library directories Libcurl in the additional include directory Libcurl

3) Add pre-compiled macros Use_openssl and Curl_staticlib

4) Add as dependent libraries

Crypt32.lib
Ws2_32.lib
Wldap32.lib
Libcurl.lib

Note the version corresponds

3, code example

[CPP]View PlainCopyprint?

2. #include <iostream>
4. #include <string>
6. #include "curl/curl.h"
8. Using namespace std;
12. #pragma comment (lib, "Ws2_32.lib")
14. #pragma comment (lib, "Wldap32.lib")
16. #pragma comment (lib, "Libcurl.lib")
20. Reply of the Requery
22. size_t req_reply (void *ptr, size_t size, size_t nmemb, void *stream)
24. {
26. cout << "----->reply" << Endl;
28. String *str = (string*) stream;
30. cout << *str << Endl;
32. (*STR). Append ((char*) ptr, size*nmemb);
34. return size * NMEMB;
36. }
40. HTTP GET
42. Curlcode curl_get_req (const std::string &url, std::string &response)
44. {
46. //Init Curl
48. CURL *curl = Curl_easy_init ();
50. //RES code
52. Curlcode Res;
54. if (Curl)
56. {
58. //Set params
60. Curl_easy_setopt (Curl, Curlopt_url, url.c_str ()); //URL
62. Curl_easy_setopt (Curl, Curlopt_ssl_verifypeer, false); //If want to use HTTPS
64. Curl_easy_setopt (Curl, Curlopt_ssl_verifyhost, false); //Set peer and host verify false
66. Curl_easy_setopt (Curl, curlopt_verbose, 1);
68. Curl_easy_setopt (Curl, curlopt_readfunction, NULL);
70. Curl_easy_setopt (Curl, curlopt_writefunction, req_reply);
72. Curl_easy_setopt (Curl, Curlopt_writedata, (void *) &response);
74. Curl_easy_setopt (Curl, curlopt_nosignal, 1);
76. Curl_easy_setopt (Curl, Curlopt_header, 1);
78. Curl_easy_setopt (Curl, curlopt_connecttimeout, 3); //Set transport and time out time
80. Curl_easy_setopt (Curl, curlopt_timeout, 3);
82. //Start req
84. res = curl_easy_perform (curl);
86. }
88. //Release Curl
90. Curl_easy_cleanup (curl);
92. return res;
94. }
98. HTTP POST
100. Curlcode curl_post_req (const string &url, const string &postparams, String &response)
102. {
104. //Init Curl
106. CURL *curl = Curl_easy_init ();
108. //RES code
110. Curlcode Res;
112. if (Curl)
114. {
116. //Set params
118. Curl_easy_setopt (Curl, curlopt_post, 1); //Post req
120. Curl_easy_setopt (Curl, Curlopt_url, url.c_str ()); //URL
122. Curl_easy_setopt (Curl, Curlopt_postfields, postparams.c_str ()); //params
124. Curl_easy_setopt (Curl, Curlopt_ssl_verifypeer, false); //If want to use HTTPS
126. Curl_easy_setopt (Curl, Curlopt_ssl_verifyhost, false); //Set peer and host verify false
128. Curl_easy_setopt (Curl, curlopt_verbose, 1);
130. Curl_easy_setopt (Curl, curlopt_readfunction, NULL);
132. Curl_easy_setopt (Curl, curlopt_writefunction, req_reply);
134. Curl_easy_setopt (Curl, Curlopt_writedata, (void *) &response);
136. Curl_easy_setopt (Curl, curlopt_nosignal, 1);
138. Curl_easy_setopt (Curl, Curlopt_header, 1);
140. Curl_easy_setopt (Curl, curlopt_connecttimeout, 3);
142. Curl_easy_setopt (Curl, curlopt_timeout, 3);
144. //Start req
146. res = curl_easy_perform (curl);
148. }
150. //Release Curl
152. Curl_easy_cleanup (curl);
154. return res;
156. }
160. int main ()
162. {
164. //Global init
166. Curl_global_init (Curl_global_all);
170. //Test get Requery
172. String geturlstr = "Http://cn.bing.com/images/trending?form=Z9LH";
174. String Getresponsestr;
176. Auto res = Curl_get_req (geturlstr, GETRESPONSESTR);
178. if (res! = CURLE_OK)
180. Cerr << "Curl_easy_perform () Failed:" + string (Curl_easy_strerror (res)) << Endl;
182. Else
184. cout << getresponsestr << Endl;
188. //test post Requery
190. String posturlstr = "https://www.baidu.com/s";
192. String postparams = "F=8&rsv_bp=1&rsv_idx=1&word=picture&tn=98633779_hao_pg";
194. String Postresponsestr;
196. Auto res = Curl_post_req (posturlstr, Postparams, POSTRESPONSESTR);
198. if (res! = CURLE_OK)
200. Cerr << "Curl_easy_perform () Failed:" + string (Curl_easy_strerror (res)) << Endl;
202. Else
204. cout << postresponsestr << Endl;
208. //Global release
210. Curl_global_cleanup ();
212. System ("pause");
214. return 0;
216. }

• Get and post can be used to request HTML information, or you can request XML and JSON strings
• Custom header fields and cookies can be added
• This is the simple interface of Libcurl, basically the same as the blocking test request, Libcurl has the higher order asynchronous concurrency interface, the use more complex

http://blog.csdn.net/u012234115/article/details/71371962

C + + uses the Libcurl library to send HTTP requests (get and post can be used to request HTML information or to request XML and JSON strings)