1 /*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel (at) 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 * Issue an HTTP POST and provide the data through the read callback. 24 * </DESC> 25 */ 26 #include <stdio.h> 27 #include <string.h> 28 #include <curl/curl.h> 29 30 /* silly test data to POST */ 31 static const char data[]="Lorem ipsum dolor sit amet, consectetur adipiscing " 32 "elit. Sed vel urna neque. Ut quis leo metus. Quisque eleifend, ex at " 33 "laoreet rhoncus, odio ipsum semper metus, at tempus ante urna in mauris. " 34 "Suspendisse ornare tempor venenatis. Ut dui neque, pellentesque a varius " 35 "eget, mattis vitae ligula. Fusce ut pharetra est. Ut ullamcorper mi ac " 36 "sollicitudin semper. Praesent sit amet tellus varius, posuere nulla non, " 37 "rhoncus ipsum."; 38 39 struct WriteThis { 40 const char *readptr; 41 size_t sizeleft; 42 }; 43 44 static size_t read_callback(void *dest, size_t size, size_t nmemb, void *userp) 45 { 46 struct WriteThis *wt = (struct WriteThis *)userp; 47 size_t buffer_size = size*nmemb; 48 49 if(wt->sizeleft) { 50 /* copy as much as possible from the source to the destination */ 51 size_t copy_this_much = wt->sizeleft; 52 if(copy_this_much > buffer_size) 53 copy_this_much = buffer_size; 54 memcpy(dest, wt->readptr, copy_this_much); 55 56 wt->readptr += copy_this_much; 57 wt->sizeleft -= copy_this_much; 58 return copy_this_much; /* we copied this many bytes */ 59 } 60 61 return 0; /* no more data left to deliver */ 62 } 63 64 int main(void) 65 { 66 CURL *curl; 67 CURLcode res; 68 69 struct WriteThis wt; 70 71 wt.readptr = data; 72 wt.sizeleft = strlen(data); 73 74 /* In windows, this will init the winsock stuff */ 75 res = curl_global_init(CURL_GLOBAL_DEFAULT); 76 /* Check for errors */ 77 if(res != CURLE_OK) { 78 fprintf(stderr, "curl_global_init() failed: %s\n", 79 curl_easy_strerror(res)); 80 return 1; 81 } 82 83 /* get a curl handle */ 84 curl = curl_easy_init(); 85 if(curl) { 86 /* First set the URL that is about to receive our POST. */ 87 curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/index.cgi"); 88 89 /* Now specify we want to POST data */ 90 curl_easy_setopt(curl, CURLOPT_POST, 1L); 91 92 /* we want to use our own read function */ 93 curl_easy_setopt(curl, CURLOPT_READFUNCTION, read_callback); 94 95 /* pointer to pass to our read function */ 96 curl_easy_setopt(curl, CURLOPT_READDATA, &wt); 97 98 /* get verbose debug output please */ 99 curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L); 100 101 /* 102 If you use POST to a HTTP 1.1 server, you can send data without knowing 103 the size before starting the POST if you use chunked encoding. You 104 enable this by adding a header like "Transfer-Encoding: chunked" with 105 CURLOPT_HTTPHEADER. With HTTP 1.0 or without chunked transfer, you must 106 specify the size in the request. 107 */ 108 #ifdef USE_CHUNKED 109 { 110 struct curl_slist *chunk = NULL; 111 112 chunk = curl_slist_append(chunk, "Transfer-Encoding: chunked"); 113 res = curl_easy_setopt(curl, CURLOPT_HTTPHEADER, chunk); 114 /* use curl_slist_free_all() after the *perform() call to free this 115 list again */ 116 } 117 #else 118 /* Set the expected POST size. If you want to POST large amounts of data, 119 consider CURLOPT_POSTFIELDSIZE_LARGE */ 120 curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, (long)wt.sizeleft); 121 #endif 122 123 #ifdef DISABLE_EXPECT 124 /* 125 Using POST with HTTP 1.1 implies the use of a "Expect: 100-continue" 126 header. You can disable this header with CURLOPT_HTTPHEADER as usual. 127 NOTE: if you want chunked transfer too, you need to combine these two 128 since you can only set one list of headers with CURLOPT_HTTPHEADER. */ 129 130 /* A less good option would be to enforce HTTP 1.0, but that might also 131 have other implications. */ 132 { 133 struct curl_slist *chunk = NULL; 134 135 chunk = curl_slist_append(chunk, "Expect:"); 136 res = curl_easy_setopt(curl, CURLOPT_HTTPHEADER, chunk); 137 /* use curl_slist_free_all() after the *perform() call to free this 138 list again */ 139 } 140 #endif 141 142 /* Perform the request, res will get the return code */ 143 res = curl_easy_perform(curl); 144 /* Check for errors */ 145 if(res != CURLE_OK) 146 fprintf(stderr, "curl_easy_perform() failed: %s\n", 147 curl_easy_strerror(res)); 148 149 /* always cleanup */ 150 curl_easy_cleanup(curl); 151 } 152 curl_global_cleanup(); 153 return 0; 154 } 155
