Redirect to fetch if there is an issue

nginx.conf

@@ -19,13 +19,14 @@ http {
 		charset utf-8;
 		access_log /srv/http/u/greptweet.access.log;
 		error_log /srv/http/u/greptweet.error.log;
+		error_page 404 403 =303 /404.php;
 
 		location / {
 			index index.php index.html;
 			rewrite ^/f/(.*)$ /create.php?id=$1 last;
 		}
 
-		location ~ \.(svg|txt)$ {
+		location ~ \.(txt)$ {
 			add_header  Content-Encoding  gzip;
 			gzip off;
 		}

www/404.php

@@ -0,0 +1,11 @@
+<?php
+if (preg_match('#^/u/#', $_SERVER["REQUEST_URI"])) {
+$username = basename($_SERVER["REQUEST_URI"]);
+	if ((!empty($username)) && (strlen($username < 16)) && preg_match('/^[A-Za-z0-9_]+$/', $username)) {
+	header("Location:http://" . $_SERVER["HTTP_HOST"] . "/f/" . $username);
+	die();
+	}
+}
+?>
+<img style="width: 20%;" src=/icons/greptweet_birdie.svg>
+<h1>Error <?php echo $_SERVER["REQUEST_URI"]; ?></h1>