Optional: Allow uploading by URL

inc/config.php

@@ -1314,6 +1314,6 @@
 	// is the absolute maximum, because MySQL cannot handle table names greater than 64 characters.
 	$config['board_regex'] = '[0-9a-zA-Z$_\x{0080}-\x{FFFF}]{1,58}';
 
-	// Complex regular expression to catch URLs.
-	$config['url_regex'] = '/' . '(https?|ftp):\/\/' . '(([\w\-]+\.)+[a-zA-Z]{2,6}|\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})' . '(:\d+)?' . '(\/([\w\-~.#\/?=&;:+%!*\[\]@$\'()+,|\^]+)?)?' . '/';
+	// Regex for URLs.
+	$config['url_regex'] = '@^(?i)\b((?:[a-z][\w-]+:(?:/{1,3}|[a-z0-9%])|www\d{0,3}[.]|[a-z0-9.\-]+[.][a-z]{2,4}/)(?:[^\s()<>]+|\(([^\s()<>]+|(\([^\s()<>]+\)))*\))+(?:\(([^\s()<>]+|(\([^\s()<>]+\)))*\)|[^\s`!()\[\]{};:\'".,<>?«»“”‘’]))$@';
 

post.php

@@ -268,6 +268,46 @@ if (isset($_POST['delete'])) {
 			$_POST['subject'] = '';
 	}
 	
+	if ($config['allow_upload_by_url'] && isset($_POST['file_url']) && !empty($_POST['file_url'])) {
+		$post['file_url'] = $_POST['file_url'];
+		if (!preg_match($config['url_regex'], $post['file_url']))
+			error($config['error']['invalidimg']);
+		
+		
+		$post['extension'] = strtolower(mb_substr($post['file_url'], mb_strrpos($post['file_url'], '.') + 1));
+		if (!in_array($post['extension'], $config['allowed_ext']) && !in_array($post['extension'], $config['allowed_ext_files']))
+			error($config['error']['unknownext']);
+
+		$post['file_tmp'] = tempnam($config['tmp'], 'url');
+		register_shutdown_function('unlink', $post['file_tmp']);
+		
+		$fp = fopen($post['file_tmp'], 'w');
+		
+		$curl = curl_init();
+		curl_setopt($curl, CURLOPT_URL, $post['file_url']);
+		curl_setopt($curl, CURLOPT_FAILONERROR, true);
+		curl_setopt($curl, CURLOPT_FOLLOWLOCATION, false);
+		curl_setopt($curl, CURLOPT_CONNECTTIMEOUT, 5);
+		curl_setopt($curl, CURLOPT_TIMEOUT, 15);
+		curl_setopt($curl, CURLOPT_USERAGENT, 'Tinyboard');
+		curl_setopt($curl, CURLOPT_BINARYTRANSFER, true);
+		curl_setopt($curl, CURLOPT_FILE, $fp);
+		
+		if (curl_exec($curl) === false)
+			error($config['error']['nomove']);
+		
+		curl_close($curl);
+		
+		fclose($fp);
+
+		$_FILES['file'] = array(
+			'name' => basename($post['file_url']),
+			'tmp_name' => $post['file_tmp'],
+			'error' => 0,
+			'size' => filesize($post['file_tmp'])
+		);
+	}
+	
 	// Check for a file
 	if ($post['op'] && !isset($post['no_longer_require_an_image_for_op'])) {
 		if (!isset($_FILES['file']['tmp_name']) || $_FILES['file']['tmp_name'] == '' && $config['force_image_op'])
@@ -545,7 +585,10 @@ if (isset($_POST['delete'])) {
 		}
 		
 		if (!isset($dont_copy_file) || !$dont_copy_file) {
-			if (!@move_uploaded_file($upload, $post['file']))
+			if (isset($post['file_tmp'])) {
+				if (!@rename($upload, $post['file']))
+					error($config['error']['nomove']);
+			} elseif (!@move_uploaded_file($upload, $post['file']))
 				error($config['error']['nomove']);
 		}
 	}

templates/main.js

@@ -175,7 +175,7 @@ function dopost(form) {
 	saved[document.location] = form.elements['body'].value;
 	sessionStorage.body = JSON.stringify(saved);
 	
-	return form.elements['body'].value != "" || form.elements['file'].value != "";
+	return form.elements['body'].value != "" || form.elements['file'].value != "" || (form.elements.file_url && form.elements['file_url'].value != "");
 }
 
 function citeReply(id) {

templates/post_form.html

@@ -73,6 +73,13 @@
 			</th>
 			<td>
 				<input type="file" name="file">
+				{% if config.allow_upload_by_url %}
+					<br>
+					<div style="float:none;text-align:left">
+						<label for="file_url">{% trans %}Or URL{% endtrans %}</label>: 
+						<input style="display:inline" type="text" id="file_url" name="file_url" size="35">
+					</div>
+				{% endif %}
 				{{ antibot.html() }}
 			</td>
 		</tr>