getredirect.c: a new example

docs/examples/Makefile.inc

@@ -5,7 +5,7 @@
 #                            | (__| |_| |  _ <| |___
 #                             \___|\___/|_| \_\_____|
 #
-# Copyright (C) 1998 - 2015, Daniel Stenberg, <daniel@haxx.se>, et al.
+# Copyright (C) 1998 - 2016, 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
@@ -32,7 +32,7 @@ check_PROGRAMS = 10-at-a-time anyauthput cookie_interface debug fileupload \
   imap-list imap-lsub imap-fetch imap-store imap-append imap-examine       \
   imap-search imap-create imap-delete imap-copy imap-noop imap-ssl         \
   imap-tls imap-multi url2file sftpget ftpsget postinmemory http2-download \
-  http2-upload http2-serverpush
+  http2-upload http2-serverpush getredirect.c
 
 # 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/getredirect.c

+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2016, 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 http://curl.haxx.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>
+ * Show how to extract Location: header and URL to redirect to.
+ * </DESC>
+ */
+#include <stdio.h>
+#include <curl/curl.h>
+
+int main(void)
+{
+  CURL *curl;
+  CURLcode res;
+  char *location;
+  long response_code;
+
+  curl = curl_easy_init();
+  if(curl) {
+    curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");
+
+    /* example.com is redirected, figure out the redirection! */
+
+    /* Perform the request, res will get the return code */
+    res = curl_easy_perform(curl);
+    /* Check for errors */
+    if(res != CURLE_OK)
+      fprintf(stderr, "curl_easy_perform() failed: %s\n",
+              curl_easy_strerror(res));
+    else {
+      res = curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &response_code);
+      if((res == CURLE_OK) &&
+         ((code / 100) != 3)) {
+        /* a redirect implies a 3xx response code */
+        fprintf(stderr, "Not a redirect.\n");
+      }
+      else {
+        res = curl_easy_getinfo(curl, CURLINFO_REDIRECT_URL, &location);
+
+        if((res == CURLE_OK) && location) {
+          /* This is the new absolute URL that you could redirect to, even if
+           * the Location: response header may have been a relative URL. */
+          printf("Redirected to: %s\n", location);
+        }
+      }
+    }
+
+    /* always cleanup */
+    curl_easy_cleanup(curl);
+  }
+  return 0;
+}