multi-formadd.c
/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. * * This software is licensed as described in the file COPYING, which * you should have received as part of this distribution. The terms * are also available at https://curl.se/docs/copyright.html. * * You may opt to use, copy, modify, merge, publish, distribute and/or sell * copies of the Software, and permit persons to whom the Software is * furnished to do so, under the terms of the COPYING file. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * * SPDX-License-Identifier: curl * ***************************************************************************/ /* <DESC> * using the multi interface to do a multipart formpost without blocking * </DESC> */ /* * Warning: this example uses the deprecated form API. See "multi-post.c" * for a similar example using the mime API. */ #include <stdio.h> #include <string.h> #include <curl/curl.h> int main(void) { CURL *curl; struct curl_httppost *formpost = NULL; struct curl_httppost *lastptr = NULL; struct curl_slist *headerlist = NULL; static const char buf[] = "Expect:"; CURLcode result = curl_global_init(CURL_GLOBAL_ALL); if(result != CURLE_OK) return (int)result; CURL_IGNORE_DEPRECATION( /* Fill in the file upload field. This makes libcurl load data from the given filename when curl_easy_perform() is called. */ curl_formadd(&formpost, &lastptr, CURLFORM_COPYNAME, "sendfile", CURLFORM_FILE, "multi-formadd.c", CURLFORM_END); /* Fill in the filename field */ curl_formadd(&formpost, &lastptr, CURLFORM_COPYNAME, "filename", CURLFORM_COPYCONTENTS, "multi-formadd.c", CURLFORM_END); /* Fill in the submit field too, even if this is rarely needed */ curl_formadd(&formpost, &lastptr, CURLFORM_COPYNAME, "submit", CURLFORM_COPYCONTENTS, "send", CURLFORM_END); ) /* initialize custom header list (stating that Expect: 100-continue is not wanted */ headerlist = curl_slist_append(headerlist, buf); curl = curl_easy_init(); if(curl) { CURLM *multi; multi = curl_multi_init(); if(multi) { int still_running = 0; /* what URL that receives this POST */ curl_easy_setopt(curl, CURLOPT_URL, "https://www.example.com/upload.cgi"); curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L); curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headerlist); CURL_IGNORE_DEPRECATION( curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost); ) curl_multi_add_handle(multi, curl); do { CURLMcode mresult = curl_multi_perform(multi, &still_running); if(still_running) /* wait for activity, timeout or "nothing" */ mresult = curl_multi_poll(multi, NULL, 0, 1000, NULL); if(mresult) break; } while(still_running); curl_multi_cleanup(multi); } /* always cleanup */ curl_easy_cleanup(curl); } CURL_IGNORE_DEPRECATION( /* then cleanup the formpost chain */ curl_formfree(formpost); ) /* free slist */ curl_slist_free_all(headerlist); curl_global_cleanup(); return 0; }
Notice
This source code example is simplified and may ignore return
codes and error checks. We do this to highlight the libcurl function calls and
related options and reduce unrelated code.
A real-world application does of course properly check every return value and exit correctly at the first serious error.