# This code is licensed under the MIT license
	#
	####################################################################
	#
	# These are global options. You can set them before calling the autolinking
	# functions to change the output.
	#
	$GLOBALS['autolink_options'] = [
		# Should http:// be visibly stripped from the front
		# of URLs?
		'strip_protocols' => false,
	];
	####################################################################
	function autolink($text, $limit=30, $tagfill='', $auto_title = true){
		$text = autolink_do($text, '![a-z][a-z-]+://!i',	$limit, $tagfill, $auto_title);
		$text = autolink_do($text, '!(mailto|skype):!i',	$limit, $tagfill, $auto_title);
		$text = autolink_do($text, '!www\\.!i',			$limit, $tagfill, $auto_title, 'http://');
		return $text;
	}
	####################################################################
	function autolink_do($text, $sub, $limit, $tagfill, $auto_title, $force_prefix=null){
		$text_l = StrToLower($text);
		$cursor = 0;
		$loop = 1;
		$buffer = '';
		while (($cursor < strlen($text)) && $loop){
			$ok = 1;
			$matched = preg_match($sub, $text_l, $m, PREG_OFFSET_CAPTURE, $cursor);
			if (!$matched){
				$loop = 0;
				$ok = 0;
			}else{
				$pos = $m[0][1];
				$sub_len = strlen($m[0][0]);
				$pre_hit = substr($text, $cursor, $pos-$cursor);
				$hit = substr($text, $pos, $sub_len);
				$pre = substr($text, 0, $pos);
				$post = substr($text, $pos + $sub_len);
				$fail_text = $pre_hit.$hit;
				$fail_len = strlen($fail_text);
				#
				# substring found - first check to see if we're inside a link tag already...
				#
				$bits = preg_split('!!i', $pre);
				$last_bit = array_pop($bits);
				if (preg_match("!\n";
					$ok = 0;
					$cursor += $fail_len;
					$buffer .= $fail_text;
				}
			}
			#
			# looks like a nice spot to autolink from - check the pre
			# to see if there was whitespace before this match
			#
			if ($ok){
				if ($pre){
					if (!preg_match('![\s\(\[\{>]$!s', $pre)){
						#echo "fail 2 at $cursor ($pre)
\n";
						$ok = 0;
						$cursor += $fail_len;
						$buffer .= $fail_text;
					}
				}
			}
			#
			# we want to autolink here - find the extent of the url
			#
			if ($ok){
				if (preg_match('/^([a-z0-9\-\.\/\-_%~!?=,:;&+*#@\(\)\$]+)/i', $post, $matches)){
					$url = $hit.$matches[1];
					$cursor += strlen($url) + strlen($pre_hit);
					$buffer .= $pre_hit;
					$url = html_entity_decode($url);
					#
					# remove trailing punctuation from url
					#
					while (preg_match('|[.,!;:?]$|', $url)){
						$url = substr($url, 0, strlen($url)-1);
						$cursor--;
					}
					foreach (['()', '[]', '{}'] as $pair){
						$o = substr($pair, 0, 1);
						$c = substr($pair, 1, 1);
						if (preg_match("!^(\\$c|^)[^\\$o]+\\$c$!", $url)){
							$url = substr($url, 0, strlen($url)-1);
							$cursor--;
						}
					}
					#
					# nice-i-fy url here
					#
					$link_url = $url;
					$display_url = $url;
					if ($force_prefix) $link_url = $force_prefix.$link_url;
					if ($GLOBALS['autolink_options']['strip_protocols']){
						if (preg_match('!^(http|https)://!i', $display_url, $m)){
							$display_url = substr($display_url, strlen($m[1])+3);
						}
					}
					$display_url = autolink_label($display_url, $limit);
					#
					# add the url
					#
					
					$currentTagfill = $tagfill;
					if ($display_url != $link_url && !preg_match('@title=@msi',$currentTagfill) && $auto_title) {
						$display_quoted = preg_quote($display_url, '!');
						if (!preg_match("!^(http|https)://{$display_quoted}$!i", $link_url)){
							$currentTagfill .= ' title="'.$link_url.'"';
						}
					}
					$link_url_enc = HtmlSpecialChars($link_url);
					$display_url_enc = HtmlSpecialChars($display_url);
					$buffer .= "{$display_url_enc}";
				
				}else{
					#echo "fail 3 at $cursor
\n";
					$ok = 0;
					$cursor += $fail_len;
					$buffer .= $fail_text;
				}
			}
		}
		#
		# add everything from the cursor to the end onto the buffer.
		#
		$buffer .= substr($text, $cursor);
		return $buffer;
	}
	####################################################################
	function autolink_label($text, $limit){
		if (!$limit){ return $text; }
		if (strlen($text) > $limit){
			return substr($text, 0, $limit-3).'...';
		}
		return $text;
	}
	####################################################################
	function autolink_email($text, $tagfill=''){
		$atom = '[^()<>@,;:\\\\".\\[\\]\\x00-\\x20\\x7f]+'; # from RFC822
		#die($atom);
		$text_l = StrToLower($text);
		$cursor = 0;
		$loop = 1;
		$buffer = '';
		while(($cursor < strlen($text)) && $loop){
			#
			# find an '@' symbol
			#
			$ok = 1;
			$pos = strpos($text_l, '@', $cursor);
			if ($pos === false){
				$loop = 0;
				$ok = 0;
			}else{
				$pre = substr($text, $cursor, $pos-$cursor);
				$hit = substr($text, $pos, 1);
				$post = substr($text, $pos + 1);
				$fail_text = $pre.$hit;
				$fail_len = strlen($fail_text);
				#die("$pre::$hit::$post::$fail_text");
				#
				# substring found - first check to see if we're inside a link tag already...
				#
				$bits = preg_split('!!i', $pre);
				$last_bit = array_pop($bits);
				if (preg_match("!\n";
					$ok = 0;
					$cursor += $fail_len;
					$buffer .= $fail_text;
				}
			}
			#
			# check backwards
			#
			if ($ok){
				if (preg_match("!($atom(\.$atom)*)\$!", $pre, $matches)){
					# move matched part of address into $hit
					$len = strlen($matches[1]);
					$plen = strlen($pre);
					$hit = substr($pre, $plen-$len).$hit;
					$pre = substr($pre, 0, $plen-$len);
				}else{
					#echo "fail 2 at $cursor ($pre)
\n";
					$ok = 0;
					$cursor += $fail_len;
					$buffer .= $fail_text;
				}
			}
			#
			# check forwards
			#
			if ($ok){
				if (preg_match("!^($atom(\.$atom)*)!", $post, $matches)){
					# move matched part of address into $hit
					$len = strlen($matches[1]);
					$hit .= substr($post, 0, $len);
					$post = substr($post, $len);
				}else{
					#echo "fail 3 at $cursor ($post)
\n";
					$ok = 0;
					$cursor += $fail_len;
					$buffer .= $fail_text;
				}
			}
			#
			# commit
			#
			if ($ok) {
				$cursor += strlen($pre) + strlen($hit);
				$buffer .= $pre;
				$buffer .= "$hit";
			}
		}
		#
		# add everything from the cursor to the end onto the buffer.
		#
		$buffer .= substr($text, $cursor);
		return $buffer;
	}
	####################################################################
?>