httpput-postfields.c: new example doing PUT with POSTFIELDS

Proposed-by: Jeroen Ooms
Ref: #6186
Closes #6188

docs/examples/Makefile.inc

@@ -36,7 +36,7 @@ check_PROGRAMS = 10-at-a-time anyauthput cookie_interface debug fileupload \
   ftpuploadresume sslbackend postit2-formadd multi-formadd                 \
   shared-connection-cache sftpuploadresume http2-pushinmemory parseurl     \
   urlapi imap-authzid pop3-authzid smtp-authzid http3 altsvc               \
-  http3-present multi-poll
+  http3-present multi-poll httpput-postfields
 
 # These examples require external dependencies that may not be commonly
 # available on POSIX systems, so don't bother attempting to compile them here.

docs/examples/httpput-postfields.c

@@ -0,0 +1,101 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2020, 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.
+ *
+ ***************************************************************************/
+/* <DESC>
+ * HTTP PUT using CURLOPT_POSTFIELDS
+ * </DESC>
+ */
+#include <stdio.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <curl/curl.h>
+
+static const char olivertwist[]=
+  "Among other public buildings in a certain town, which for many reasons "
+  "it will be prudent to refrain from mentioning, and to which I will assign "
+  "no fictitious name, there is one anciently common to most towns, great or "
+  "small: to wit, a workhouse; and in this workhouse was born; on a day and "
+  "date which I need not trouble myself to repeat, inasmuch as it can be of "
+  "no possible consequence to the reader, in this stage of the business at "
+  "all events; the item of mortality whose name is prefixed to the head of "
+  "this chapter.";
+
+/*
+ * This example shows a HTTP PUT operation that sends a fixed buffer with
+ * CURLOPT_POSTFIELDS to the URL given as an argument.
+ */
+
+int main(int argc, char **argv)
+{
+  CURL *curl;
+  CURLcode res;
+  char *url;
+
+  if(argc < 2)
+    return 1;
+
+  url = argv[1];
+
+  /* In windows, this will init the winsock stuff */
+  curl_global_init(CURL_GLOBAL_ALL);
+
+  /* get a curl handle */
+  curl = curl_easy_init();
+  if(curl) {
+    struct curl_slist *headers = NULL;
+
+    /* default type with postfields is application/x-www-form-urlencoded,
+       change it if you want */
+    headers = curl_slist_append(headers, "Content-Type: literature/classic");
+    curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
+
+    /* pass on content in request body. When CURLOPT_POSTFIELDSIZE isn't used,
+       curl does strlen to get the size. */
+    curl_easy_setopt(curl, CURLOPT_POSTFIELDS, olivertwist);
+
+    /* override the POST implied by CURLOPT_POSTFIELDS
+     *
+     * Warning: CURLOPT_CUSTOMREQUEST is problematic, especially if you want
+     * to follow redirects. Be aware.
+     */
+    curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "PUT");
+
+    /* specify target URL, and note that this URL should include a file
+       name, not only a directory */
+    curl_easy_setopt(curl, CURLOPT_URL, url);
+
+    /* Now run off and do what you've been told! */
+    res = curl_easy_perform(curl);
+    /* Check for errors */
+    if(res != CURLE_OK)
+      fprintf(stderr, "curl_easy_perform() failed: %s\n",
+              curl_easy_strerror(res));
+
+    /* always cleanup */
+    curl_easy_cleanup(curl);
+
+    /* free headers */
+    curl_slist_free_all(headers);
+  }
+
+  curl_global_cleanup();
+  return 0;
+}