1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.haxx.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22 /* <DESC>
23 * Make a HTTP POST with data from memory and receive response in memory.
24 * </DESC>
25 */
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <curl/curl.h>
30
31 struct MemoryStruct {
32 char *memory;
33 size_t size;
34 };
35
36 static size_t
WriteMemoryCallback(void * contents,size_t size,size_t nmemb,void * userp)37 WriteMemoryCallback(void *contents, size_t size, size_t nmemb, void *userp)
38 {
39 size_t realsize = size * nmemb;
40 struct MemoryStruct *mem = (struct MemoryStruct *)userp;
41
42 mem->memory = realloc(mem->memory, mem->size + realsize + 1);
43 if(mem->memory == NULL) {
44 /* out of memory! */
45 printf("not enough memory (realloc returned NULL)\n");
46 return 0;
47 }
48
49 memcpy(&(mem->memory[mem->size]), contents, realsize);
50 mem->size += realsize;
51 mem->memory[mem->size] = 0;
52
53 return realsize;
54 }
55
main(void)56 int main(void)
57 {
58 CURL *curl;
59 CURLcode res;
60 struct MemoryStruct chunk;
61 static const char *postthis="Field=1&Field=2&Field=3";
62
63 chunk.memory = malloc(1); /* will be grown as needed by realloc above */
64 chunk.size = 0; /* no data at this point */
65
66 curl_global_init(CURL_GLOBAL_ALL);
67 curl = curl_easy_init();
68 if(curl) {
69
70 curl_easy_setopt(curl, CURLOPT_URL, "http://www.example.org/");
71
72 /* send all data to this function */
73 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);
74
75 /* we pass our 'chunk' struct to the callback function */
76 curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *)&chunk);
77
78 /* some servers don't like requests that are made without a user-agent
79 field, so we provide one */
80 curl_easy_setopt(curl, CURLOPT_USERAGENT, "libcurl-agent/1.0");
81
82 curl_easy_setopt(curl, CURLOPT_POSTFIELDS, postthis);
83
84 /* if we don't provide POSTFIELDSIZE, libcurl will strlen() by
85 itself */
86 curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, (long)strlen(postthis));
87
88 /* Perform the request, res will get the return code */
89 res = curl_easy_perform(curl);
90 /* Check for errors */
91 if(res != CURLE_OK) {
92 fprintf(stderr, "curl_easy_perform() failed: %s\n",
93 curl_easy_strerror(res));
94 }
95 else {
96 /*
97 * Now, our chunk.memory points to a memory block that is chunk.size
98 * bytes big and contains the remote file.
99 *
100 * Do something nice with it!
101 */
102 printf("%s\n",chunk.memory);
103 }
104
105 /* always cleanup */
106 curl_easy_cleanup(curl);
107
108 free(chunk.memory);
109
110 /* we're done with libcurl, so clean it up */
111 curl_global_cleanup();
112 }
113 return 0;
114 }
115