<?php
/**
 * Main Wordpress Formatting API.
 *
 * Handles many functions for formatting output.
 *
 * @package WordPress
 **/

/**
 * Replaces common plain text characters into formatted entities
 *
 * As an example,
 * <code>
 * 'cause today's effort makes it worth tomorrow's "holiday"...
 * </code>
 * Becomes:
 * <code>
 * &#8217;cause today&#8217;s effort makes it worth tomorrow&#8217;s &#8220;holiday&#8221;&#8230;
 * </code>
 * Code within certain html blocks are skipped.
 *
 * @since 0.71
 * @uses $wp_cockneyreplace Array of formatted entities for certain common phrases
 *
 * @param string $text The text to be formatted
 * @return string The string replaced with html entities
 */
function wptexturize($text) {
	global $wp_cockneyreplace;
	$next = true;
	$has_pre_parent = false;
	$output = '';
	$curl = '';
	$textarr = preg_split('/(<.*>|\[.*\])/Us', $text, -1, PREG_SPLIT_DELIM_CAPTURE);
	$stop = count($textarr);

	// if a plugin has provided an autocorrect array, use it
	if ( isset($wp_cockneyreplace) ) {
		$cockney = array_keys($wp_cockneyreplace);
		$cockneyreplace = array_values($wp_cockneyreplace);
	} else {
		$cockney = array("'tain't","'twere","'twas","'tis","'twill","'til","'bout","'nuff","'round","'cause");
		$cockneyreplace = array("&#8217;tain&#8217;t","&#8217;twere","&#8217;twas","&#8217;tis","&#8217;twill","&#8217;til","&#8217;bout","&#8217;nuff","&#8217;round","&#8217;cause");
	}

	$static_characters = array_merge(array('---', ' -- ', '--', 'xn&#8211;', '...', '``', '\'s', '\'\'', ' (tm)'), $cockney);
	$static_replacements = array_merge(array('&#8212;', ' &#8212; ', '&#8211;', 'xn--', '&#8230;', '&#8220;', '&#8217;s', '&#8221;', ' &#8482;'), $cockneyreplace);

	$dynamic_characters = array('/\'(\d\d(?:&#8217;|\')?s)/', '/(\s|\A|")\'/', '/(\d+)"/', '/(\d+)\'/', '/(\S)\'([^\'\s])/', '/(\s|\A)"(?!\s)/', '/"(\s|\S|\Z)/', '/\'([\s.]|\Z)/', '/(\d+)x(\d+)/');
	$dynamic_replacements = array('&#8217;$1','$1&#8216;', '$1&#8243;', '$1&#8242;', '$1&#8217;$2', '$1&#8220;$2', '&#8221;$1', '&#8217;$1', '$1&#215;$2');

	for ( $i = 0; $i < $stop; $i++ ) {
		$curl = $textarr[$i];

		if ( !empty($curl) && '<' != $curl{0} && '[' != $curl{0} && $next && !$has_pre_parent) { // If it's not a tag
			// static strings
			$curl = str_replace($static_characters, $static_replacements, $curl);
			// regular expressions
			$curl = preg_replace($dynamic_characters, $dynamic_replacements, $curl);
		} elseif (strpos($curl, '<code') !== false || strpos($curl, '<kbd') !== false || strpos($curl, '<style') !== false || strpos($curl, '<script') !== false) {
			$next = false;
		} elseif (strpos($curl, '<pre') !== false) {
			$has_pre_parent = true;
		} elseif (strpos($curl, '</pre>') !== false) {
			$has_pre_parent = false;
		} else {
			$next = true;
		}

		$curl = preg_replace('/&([^#])(?![a-zA-Z1-4]{1,8};)/', '&#038;$1', $curl);
		$output .= $curl;
	}

	return $output;
}

/**
 * Accepts matches array from preg_replace_callback in wpautop() or a string.
 *
 * Ensures that the contents of a <<pre>>...<</pre>> HTML block are not
 * converted into paragraphs or line-breaks.
 *
 * @since 1.2.0
 *
 * @param array|string $matches The array or string
 * @return string The pre block without paragraph/line-break conversion.
 */
function clean_pre($matches) {
	if ( is_array($matches) )
		$text = $matches[1] . $matches[2] . "</pre>";
	else
		$text = $matches;

	$text = str_replace('<br />', '', $text);
	$text = str_replace('<p>', "\n", $text);
	$text = str_replace('</p>', '', $text);

	return $text;
}

/**
 * Replaces double line-breaks with paragraph elements.
 *
 * A group of regex replaces used to identify text formatted with newlines and
 * replace double line-breaks with HTML paragraph tags. The remaining
 * line-breaks after conversion become <<br />> tags, unless $br is set to '0'
 * or 'false'.
 *
 * @since 0.71
 *
 * @param string $pee The text which has to be formatted.
 * @param int|bool $br Optional. If set, this will convert all remaining line-breaks after paragraphing. Default true.
 * @return string Text which has been converted into correct paragraph tags.
 */
function wpautop($pee, $br = 1) {
	$pee = $pee . "\n"; // just to make things a little easier, pad the end
	$pee = preg_replace('|<br />\s*<br />|', "\n\n", $pee);
	// Space things out a little
	$allblocks = '(?:table|thead|tfoot|caption|colgroup|tbody|tr|td|th|div|dl|dd|dt|ul|ol|li|pre|select|form|map|area|blockquote|address|math|style|input|p|h[1-6]|hr)';
	$pee = preg_replace('!(<' . $allblocks . '[^>]*>)!', "\n$1", $pee);
	$pee = preg_replace('!(</' . $allblocks . '>)!', "$1\n\n", $pee);
	$pee = str_replace(array("\r\n", "\r"), "\n", $pee); // cross-platform newlines
	if ( strpos($pee, '<object') !== false ) {
		$pee = preg_replace('|\s*<param([^>]*)>\s*|', "<param$1>", $pee); // no pee inside object/embed
		$pee = preg_replace('|\s*</embed>\s*|', '</embed>', $pee);
	}
	$pee = preg_replace("/\n\n+/", "\n\n", $pee); // take care of duplicates
	// make paragraphs, including one at the end
	$pees = preg_split('/\n\s*\n/', $pee, -1, PREG_SPLIT_NO_EMPTY);
	$pee = '';
	foreach ( $pees as $tinkle )
		$pee .= '<p>' . trim($tinkle, "\n") . "</p>\n";
	$pee = preg_replace('|<p>\s*?</p>|', '', $pee); // under certain strange conditions it could create a P of entirely whitespace
	$pee = preg_replace('!<p>([^<]+)\s*?(</(?:div|address|form)[^>]*>)!', "<p>$1</p>$2", $pee);
	$pee = preg_replace( '|<p>|', "$1<p>", $pee );
	$pee = preg_replace('!<p>\s*(</?' . $allblocks . '[^>]*>)\s*</p>!', "$1", $pee); // don't pee all over a tag
	$pee = preg_replace("|<p>(<li.+?)</p>|", "$1", $pee); // problem with nested lists
	$pee = preg_replace('|<p><blockquote([^>]*)>|i', "<blockquote$1><p>", $pee);
	$pee = str_replace('</blockquote></p>', '</p></blockquote>', $pee);
	$pee = preg_replace('!<p>\s*(</?' . $allblocks . '[^>]*>)!', "$1", $pee);
	$pee = preg_replace('!(</?' . $allblocks . '[^>]*>)\s*</p>!', "$1", $pee);
	if ($br) {
		$pee = preg_replace_callback('/<(script|style).*?<\/\\1>/s', create_function('$matches', 'return str_replace("\n", "<WPPreserveNewline />", $matches[0]);'), $pee);
		$pee = preg_replace('|(?<!<br />)\s*\n|', "<br />\n", $pee); // optionally make line breaks
		$pee = str_replace('<WPPreserveNewline />', "\n", $pee);
	}
	$pee = preg_replace('!(</?' . $allblocks . '[^>]*>)\s*<br />!', "$1", $pee);
	$pee = preg_replace('!<br />(\s*</?(?:p|li|div|dl|dd|dt|th|pre|td|ul|ol)[^>]*>)!', '$1', $pee);
	if (strpos($pee, '<pre') !== false)
		$pee = preg_replace_callback('!(<pre.*?>)(.*?)</pre>!is', 'clean_pre', $pee );
	$pee = preg_replace( "|\n</p>$|", '</p>', $pee );
	$pee = preg_replace('/<p>\s*?(' . get_shortcode_regex() . ')\s*<\/p>/s', '$1', $pee); // don't auto-p wrap shortcodes that stand alone

	return $pee;
}

/**
 * Checks to see if a string is utf8 encoded.
 *
 * @author bmorel at ssi dot fr
 *
 * @since 1.2.1
 *
 * @param string $Str The string to be checked
 * @return bool True if $Str fits a UTF-8 model, false otherwise.
 */
function seems_utf8($Str) { # by bmorel at ssi dot fr
	$length = strlen($Str);
	for ($i=0; $i < $length; $i++) {
		if (ord($Str[$i]) < 0x80) continue; # 0bbbbbbb
		elseif ((ord($Str[$i]) & 0xE0) == 0xC0) $n=1; # 110bbbbb
		elseif ((ord($Str[$i]) & 0xF0) == 0xE0) $n=2; # 1110bbbb
		elseif ((ord($Str[$i]) & 0xF8) == 0xF0) $n=3; # 11110bbb
		elseif ((ord($Str[$i]) & 0xFC) == 0xF8) $n=4; # 111110bb
		elseif ((ord($Str[$i]) & 0xFE) == 0xFC) $n=5; # 1111110b
		else return false; # Does not match any model
		for ($j=0; $j<$n; $j++) { # n bytes matching 10bbbbbb follow ?
			if ((++$i == $length) || ((ord($Str[$i]) & 0xC0) != 0x80))
			return false;
		}
	}
	return true;
}

/**
 * Converts a number of special characters into their HTML entities.
 *
 * Differs from htmlspecialchars as existing HTML entities will not be encoded.
 * Specifically changes: & to &#038;, < to &lt; and > to &gt;.
 *
 * $quotes can be set to 'single' to encode ' to &#039;, 'double' to encode " to
 * &quot;, or '1' to do both. Default is 0 where no quotes are encoded.
 *
 * @since 1.2.2
 *
 * @param string $text The text which is to be encoded.
 * @param mixed $quotes Optional. Converts single quotes if set to 'single', double if set to 'double' or both if otherwise set. Default 0.
 * @return string The encoded text with HTML entities.
 */
function wp_specialchars( $text, $quotes = 0 ) {
	// Like htmlspecialchars except don't double-encode HTML entities
	$text = str_replace('&&', '&#038;&', $text);
	$text = str_replace('&&', '&#038;&', $text);
	$text = preg_replace('/&(?:$|([^#])(?![a-z1-4]{1,8};))/', '&#038;$1', $text);
	$text = str_replace('<', '&lt;', $text);
	$text = str_replace('>', '&gt;', $text);
	if ( 'double' === $quotes ) {
		$text = str_replace('"', '&quot;', $text);
	} elseif ( 'single' === $quotes ) {
		$text = str_replace("'", '&#039;', $text);
	} elseif ( $quotes ) {
		$text = str_replace('"', '&quot;', $text);
		$text = str_replace("'", '&#039;', $text);
	}
	return $text;
}

/**
 * Encode the Unicode values to be used in the URI.
 *
 * @since 1.5.0
 *
 * @param string $utf8_string
 * @param int $length Max length of the string
 * @return string String with Unicode encoded for URI.
 */
function utf8_uri_encode( $utf8_string, $length = 0 ) {
	$unicode = '';
	$values = array();
	$num_octets = 1;
	$unicode_length = 0;

	$string_length = strlen( $utf8_string );
	for ($i = 0; $i < $string_length; $i++ ) {

		$value = ord( $utf8_string[ $i ] );

		if ( $value < 128 ) {
			if ( $length && ( $unicode_length >= $length ) )
				break;
			$unicode .= chr($value);
			$unicode_length++;
		} else {
			if ( count( $values ) == 0 ) $num_octets = ( $value < 224 ) ? 2 : 3;

			$values[] = $value;

			if ( $length && ( $unicode_length + ($num_octets * 3) ) > $length )
				break;
			if ( count( $values ) == $num_octets ) {
				if ($num_octets == 3) {
					$unicode .= '%' . dechex($values[0]) . '%' . dechex($values[1]) . '%' . dechex($values[2]);
					$unicode_length += 9;
				} else {
					$unicode .= '%' . dechex($values[0]) . '%' . dechex($values[1]);
					$unicode_length += 6;
				}

				$values = array();
				$num_octets = 1;
			}
		}
	}

	return $unicode;
}

/**
 * Converts all accent characters to ASCII characters.
 *
 * If there are no accent characters, then the string given is just returned.
 *
 * @since 1.2.1
 *
 * @param string $string Text that might have accent characters
 * @return string Filtered string with replaced "nice" characters.
 */
function remove_accents($string) {
	if ( !preg_match('/[\x80-\xff]/', $string) )
		return $string;

	if (seems_utf8($string)) {
		$chars = array(
		// Decompositions for Latin-1 Supplement
		chr(195).chr(128) => 'A', chr(195).chr(129) => 'A',
		chr(195).chr(130) => 'A', chr(195).chr(131) => 'A',
		chr(195).chr(132) => 'A', chr(195).chr(133) => 'A',
		chr(195).chr(135) => 'C', chr(195).chr(136) => 'E',
		chr(195).chr(137) => 'E', chr(195).chr(138) => 'E',
		chr(195).chr(139) => 'E', chr(195).chr(140) => 'I',
		chr(195).chr(141) => 'I', chr(195).chr(142) => 'I',
		chr(195).chr(143) => 'I', chr(195).chr(145) => 'N',
		chr(195).chr(146) => 'O', chr(195).chr(147) => 'O',
		chr(195).chr(148) => 'O', chr(195).chr(149) => 'O',
		chr(195).chr(150) => 'O', chr(195).chr(153) => 'U',
		chr(195).chr(154) => 'U', chr(195).chr(155) => 'U',
		chr(195).chr(156) => 'U', chr(195).chr(157) => 'Y',
		chr(195).chr(159) => 's', chr(195).chr(160) => 'a',
		chr(195).chr(161) => 'a', chr(195).chr(162) => 'a',
		chr(195).chr(163) => 'a', chr(195).chr(164) => 'a',
		chr(195).chr(165) => 'a', chr(195).chr(167) => 'c',
		chr(195).chr(168) => 'e', chr(195).chr(169) => 'e',
		chr(195).chr(170) => 'e', chr(195).chr(171) => 'e',
		chr(195).chr(172) => 'i', chr(195).chr(173) => 'i',
		chr(195).chr(174) => 'i', chr(195).chr(175) => 'i',
		chr(195).chr(177) => 'n', chr(195).chr(178) => 'o',
		chr(195).chr(179) => 'o', chr(195).chr(180) => 'o',
		chr(195).chr(181) => 'o', chr(195).chr(182) => 'o',
		chr(195).chr(182) => 'o', chr(195).chr(185) => 'u',
		chr(195).chr(186) => 'u', chr(195).chr(187) => 'u',
		chr(195).chr(188) => 'u', chr(195).chr(189) => 'y',
		chr(195).chr(191) => 'y',
		// Decompositions for Latin Extended-A
		chr(196).chr(128) => 'A', chr(196).chr(129) => 'a',
		chr(196).chr(130) => 'A', chr(196).chr(131) => 'a',
		chr(196).chr(132) => 'A', chr(196).chr(133) => 'a',
		chr(196).chr(134) => 'C', chr(196).chr(135) => 'c',
		chr(196).chr(136) => 'C', chr(196).chr(137) => 'c',
		chr(196).chr(138) => 'C', chr(196).chr(139) => 'c',
		chr(196).chr(140) => 'C', chr(196).chr(141) => 'c',
		chr(196).chr(142) => 'D', chr(196).chr(143) => 'd',
		chr(196).chr(144) => 'D', chr(196).chr(145) => 'd',
		chr(196).chr(146) => 'E', chr(196).chr(147) => 'e',
		chr(196).chr(148) => 'E', chr(196).chr(149) => 'e',
		chr(196).chr(150) => 'E', chr(196).chr(151) => 'e',
		chr(196).chr(152) => 'E', chr(196).chr(153) => 'e',
		chr(196).chr(154) => 'E', chr(196).chr(155) => 'e',
		chr(196).chr(156) => 'G', chr(196).chr(157) => 'g',
		chr(196).chr(158) => 'G', chr(196).chr(159) => 'g',
		chr(196).chr(160) => 'G', chr(196).chr(161) => 'g',
		chr(196).chr(162) => 'G', chr(196).chr(163) => 'g',
		chr(196).chr(164) => 'H', chr(196).chr(165) => 'h',
		chr(196).chr(166) => 'H', chr(196).chr(167) => 'h',
		chr(196).chr(168) => 'I', chr(196).chr(169) => 'i',
		chr(196).chr(170) => 'I', chr(196).chr(171) => 'i',
		chr(196).chr(172) => 'I', chr(196).chr(173) => 'i',
		chr(196).chr(174) => 'I', chr(196).chr(175) => 'i',
		chr(196).chr(176) => 'I', chr(196).chr(177) => 'i',
		chr(196).chr(178) => 'IJ',chr(196).chr(179) => 'ij',
		chr(196).chr(180) => 'J', chr(196).chr(181) => 'j',
		chr(196).chr(182) => 'K', chr(196).chr(183) => 'k',
		chr(196).chr(184) => 'k', chr(196).chr(185) => 'L',
		chr(196).chr(186) => 'l', chr(196).chr(187) => 'L',
		chr(196).chr(188) => 'l', chr(196).chr(189) => 'L',
		chr(196).chr(190) => 'l', chr(196).chr(191) => 'L',
		chr(197).chr(128) => 'l', chr(197).chr(129) => 'L',
		chr(197).chr(130) => 'l', chr(197).chr(131) => 'N',
		chr(197).chr(132) => 'n', chr(197).chr(133) => 'N',
		chr(197).chr(134) => 'n', chr(197).chr(135) => 'N',
		chr(197).chr(136) => 'n', chr(197).chr(137) => 'N',
		chr(197).chr(138) => 'n', chr(197).chr(139) => 'N',
		chr(197).chr(140) => 'O', chr(197).chr(141) => 'o',
		chr(197).chr(142) => 'O', chr(197).chr(143) => 'o',
		chr(197).chr(144) => 'O', chr(197).chr(145) => 'o',
		chr(197).chr(146) => 'OE',chr(197).chr(147) => 'oe',
		chr(197).chr(148) => 'R',chr(197).chr(149) => 'r',
		chr(197).chr(150) => 'R',chr(197).chr(151) => 'r',
		chr(197).chr(152) => 'R',chr(197).chr(153) => 'r',
		chr(197).chr(154) => 'S',chr(197).chr(155) => 's',
		chr(197).chr(156) => 'S',chr(197).chr(157) => 's',
		chr(197).chr(158) => 'S',chr(197).chr(159) => 's',
		chr(197).chr(160) => 'S', chr(197).chr(161) => 's',
		chr(197).chr(162) => 'T', chr(197).chr(163) => 't',
		chr(197).chr(164) => 'T', chr(197).chr(165) => 't',
		chr(197).chr(166) => 'T', chr(197).chr(167) => 't',
		chr(197).chr(168) => 'U', chr(197).chr(169) => 'u',
		chr(197).chr(170) => 'U', chr(197).chr(171) => 'u',
		chr(197).chr(172) => 'U', chr(197).chr(173) => 'u',
		chr(197).chr(174) => 'U', chr(197).chr(175) => 'u',
		chr(197).chr(176) => 'U', chr(197).chr(177) => 'u',
		chr(197).chr(178) => 'U', chr(197).chr(179) => 'u',
		chr(197).chr(180) => 'W', chr(197).chr(181) => 'w',
		chr(197).chr(182) => 'Y', chr(197).chr(183) => 'y',
		chr(197).chr(184) => 'Y', chr(197).chr(185) => 'Z',
		chr(197).chr(186) => 'z', chr(197).chr(187) => 'Z',
		chr(197).chr(188) => 'z', chr(197).chr(189) => 'Z',
		chr(197).chr(190) => 'z', chr(197).chr(191) => 's',
		// Euro Sign
		chr(226).chr(130).chr(172) => 'E',
		// GBP (Pound) Sign
		chr(194).chr(163) => '');

		$string = strtr($string, $chars);
	} else {
		// Assume ISO-8859-1 if not UTF-8
		$chars['in'] = chr(128).chr(131).chr(138).chr(142).chr(154).chr(158)
			.chr(159).chr(162).chr(165).chr(181).chr(192).chr(193).chr(194)
			.chr(195).chr(196).chr(197).chr(199).chr(200).chr(201).chr(202)
			.chr(203).chr(204).chr(205).chr(206).chr(207).chr(209).chr(210)
			.chr(211).chr(212).chr(213).chr(214).chr(216).chr(217).chr(218)
			.chr(219).chr(220).chr(221).chr(224).chr(225).chr(226).chr(227)
			.chr(228).chr(229).chr(231).chr(232).chr(233).chr(234).chr(235)
			.chr(236).chr(237).chr(238).chr(239).chr(241).chr(242).chr(243)
			.chr(244).chr(245).chr(246).chr(248).chr(249).chr(250).chr(251)
			.chr(252).chr(253).chr(255);

		$chars['out'] = "EfSZszYcYuAAAAAACEEEEIIIINOOOOOOUUUUYaaaaaaceeeeiiiinoooooouuuuyy";

		$string = strtr($string, $chars['in'], $chars['out']);
		$double_chars['in'] = array(chr(140), chr(156), chr(198), chr(208), chr(222), chr(223), chr(230), chr(240), chr(254));
		$double_chars['out'] = array('OE', 'oe', 'AE', 'DH', 'TH', 'ss', 'ae', 'dh', 'th');
		$string = str_replace($double_chars['in'], $double_chars['out'], $string);
	}

	return $string;
}

/**
 * Filters certain characters from the file name.
 *
 * Turns all strings to lowercase removing most characters except alphanumeric
 * with spaces, dashes and periods. All spaces and underscores are converted to
 * dashes. Multiple dashes are converted to a single dash. Finally, if the file
 * name ends with a dash, it is removed.
 *
 * @since 2.1.0
 *
 * @param string $name The file name
 * @return string Sanitized file name
 */
function sanitize_file_name( $name ) { // Like sanitize_title, but with periods
	$name = strtolower( $name );
	$name = preg_replace('/&.+?;/', '', $name); // kill entities
	$name = str_replace( '_', '-', $name );
	$name = preg_replace('/[^a-z0-9\s-.]/', '', $name);
	$name = preg_replace('/\s+/', '-', $name);
	$name = preg_replace('|-+|', '-', $name);
	$name = trim($name, '-');
	return $name;
}

/**
 * Sanitize username stripping out unsafe characters.
 *
 * If $strict is true, only alphanumeric characters (as well as _, space, ., -,
 * @) are returned.
 * Removes tags, octets, entities, and if strict is enabled, will remove all
 * non-ASCII characters. After sanitizing, it passes the username, raw username
 * (the username in the parameter), and the strict parameter as parameters for
 * the filter.
 *
 * @since 2.0.0
 * @uses apply_filters() Calls 'sanitize_user' hook on username, raw username,
 *		and $strict parameter.
 *
 * @param string $username The username to be sanitized.
 * @param bool $strict If set limits $username to specific characters. Default false.
 * @return string The sanitized username, after passing through filters.
 */
function sanitize_user( $username, $strict = false ) {
	$raw_username = $username;
	$username = strip_tags($username);
	// Kill octets
	$username = preg_replace('|%([a-fA-F0-9][a-fA-F0-9])|', '', $username);
	$username = preg_replace('/&.+?;/', '', $username); // Kill entities

	// If strict, reduce to ASCII for max portability.
	if ( $strict )
		$username = preg_replace('|[^a-z0-9 _.\-@]|i', '', $username);

	// Consolidate contiguous whitespace
	$username = preg_replace('|\s+|', ' ', $username);

	return apply_filters('sanitize_user', $username, $raw_username, $strict);
}

/**
 * Sanitizes title or use fallback title.
 *
 * Specifically, HTML and PHP tags are stripped. Further actions can be added
 * via the plugin API. If $title is empty and $fallback_title is set, the latter
 * will be used.
 *
 * @since 1.0.0
 *
 * @param string $title The string to be sanitized.
 * @param string $fallback_title Optional. A title to use if $title is empty.
 * @return string The sanitized string.
 */
function sanitize_title($title, $fallback_title = '') {
	$title = strip_tags($title);
	$title = apply_filters('sanitize_title', $title);

	if ( '' === $title || false === $title )
		$title = $fallback_title;

	return $title;
}

/**
 * Sanitizes title, replacing whitespace with dashes.
 *
 * Limits the output to alphanumeric characters, underscore (_) and dash (-).
 * Whitespace becomes a dash.
 *
 * @since 1.2.0
 *
 * @param string $title The title to be sanitized.
 * @return string The sanitized title.
 */
function sanitize_title_with_dashes($title) {
	$title = strip_tags($title);
	// Preserve escaped octets.
	$title = preg_replace('|%([a-fA-F0-9][a-fA-F0-9])|', '---$1---', $title);
	// Remove percent signs that are not part of an octet.
	$title = str_replace('%', '', $title);
	// Restore octets.
	$title = preg_replace('|---([a-fA-F0-9][a-fA-F0-9])---|', '%$1', $title);

	$title = remove_accents($title);
	if (seems_utf8($title)) {
		if (function_exists('mb_strtolower')) {
			$title = mb_strtolower($title, 'UTF-8');
		}
		$title = utf8_uri_encode($title, 200);
	}

	$title = strtolower($title);
	$title = preg_replace('/&.+?;/', '', $title); // kill entities
	$title = preg_replace('/[^%a-z0-9 _-]/', '', $title);
	$title = preg_replace('/\s+/', '-', $title);
	$title = preg_replace('|-+|', '-', $title);
	$title = trim($title, '-');

	return $title;
}

/**
 * Ensures a string is a valid SQL order by clause.
 *
 * Accepts one or more columns, with or without ASC/DESC, and also accepts
 * RAND().
 *
 * @since 2.5.1
 *
 * @param string $orderby Order by string to be checked.
 * @return string|false Returns the order by clause if it is a match, false otherwise.
 */
function sanitize_sql_orderby( $orderby ){
	preg_match('/^\s*([a-z0-9_]+(\s+(ASC|DESC))?(\s*,\s*|\s*$))+|^\s*RAND\(\s*\)\s*$/i', $orderby, $obmatches);
	if ( !$obmatches )
		return false;
	return $orderby;
}

/**
 * Converts a number of characters from a string.
 *
 * Metadata tags <<title>> and <<category>> are removed, <<br>> and <<hr>> are
 * converted into correct XHTML and Unicode characters are converted to the
 * valid range.
 *
 * @since 0.71
 *
 * @param string $content String of characters to be converted.
 * @param string $deprecated Not used.
 * @return string Converted string.
 */
function convert_chars($content, $deprecated = '') {
	// Translation of invalid Unicode references range to valid range
	$wp_htmltranswinuni = array(
	'&#128;' => '&#8364;', // the Euro sign
	'&#129;' => '',
	'&#130;' => '&#8218;', // these are Windows CP1252 specific characters
	'&#131;' => '&#402;',  // they would look weird on non-Windows browsers
	'&#132;' => '&#8222;',
	'&#133;' => '&#8230;',
	'&#134;' => '&#8224;',
	'&#135;' => '&#8225;',
	'&#136;' => '&#710;',
	'&#137;' => '&#8240;',
	'&#138;' => '&#352;',
	'&#139;' => '&#8249;',
	'&#140;' => '&#338;',
	'&#141;' => '',
	'&#142;' => '&#382;',
	'&#143;' => '',
	'&#144;' => '',
	'&#145;' => '&#8216;',
	'&#146;' => '&#8217;',
	'&#147;' => '&#8220;',
	'&#148;' => '&#8221;',
	'&#149;' => '&#8226;',
	'&#150;' => '&#8211;',
	'&#151;' => '&#8212;',
	'&#152;' => '&#732;',
	'&#153;' => '&#8482;',
	'&#154;' => '&#353;',
	'&#155;' => '&#8250;',
	'&#156;' => '&#339;',
	'&#157;' => '',
	'&#158;' => '',
	'&#159;' => '&#376;'
	);

	// Remove metadata tags
	$content = preg_replace('/<title>(.+?)<\/title>/','',$content);
	$content = preg_replace('/<category>(.+?)<\/category>/','',$content);

	// Converts lone & characters into &#38; (a.k.a. &amp;)
	$content = preg_replace('/&([^#])(?![a-z1-4]{1,8};)/i', '&#038;$1', $content);

	// Fix Word pasting
	$content = strtr($content, $wp_htmltranswinuni);

	// Just a little XHTML help
	$content = str_replace('<br>', '<br />', $content);
	$content = str_replace('<hr>', '<hr />', $content);

	return $content;
}

/**
 * Fixes javascript bugs in browsers.
 *
 * Converts unicode characters to HTML numbered entities.
 *
 * @since 1.5.0
 * @uses $is_macIE
 * @uses $is_winIE
 *
 * @param string $text Text to be made safe.
 * @return string Fixed text.
 */
function funky_javascript_fix($text) {
	// Fixes for browsers' javascript bugs
	global $is_macIE, $is_winIE;

	/** @todo use preg_replace_callback() instead */
	if ( $is_winIE || $is_macIE )
		$text =  preg_replace("/\%u([0-9A-F]{4,4})/e",  "'&#'.base_convert('\\1',16,10).';'", $text);

	return $text;
}

/**
 * Will only balance the tags if forced to and the option is set to balance tags.
 *
 * The option 'use_balanceTags' is used for whether the tags will be balanced.
 * Both the $force parameter and 'use_balanceTags' option will have to be true
 * before the tags will be balanced.
 *
 * @since 0.71
 *
 * @param string $text Text to be balanced
 * @param bool $force Forces balancing, ignoring the value of the option. Default false.
 * @return string Balanced text
 */
function balanceTags( $text, $force = false ) {
	if ( !$force && get_option('use_balanceTags') == 0 )
		return $text;
	return force_balance_tags( $text );
}

/**
 * Balances tags of string using a modified stack.
 *
 * @since 2.0.4
 *
 * @author Leonard Lin <leonard@acm.org>
 * @license GPL v2.0
 * @copyright November 4, 2001
 * @version 1.1
 * @todo Make better - change loop condition to $text in 1.2
 * @internal Modified by Scott Reilly (coffee2code) 02 Aug 2004
 *		1.1  Fixed handling of append/stack pop order of end text
 *			 Added Cleaning Hooks
 *		1.0  First Version
 *
 * @param string $text Text to be balanced.
 * @return string Balanced text.
 */
function force_balance_tags( $text ) {
	$tagstack = array(); $stacksize = 0; $tagqueue = ''; $newtext = '';
	$single_tags = array('br', 'hr', 'img', 'input'); //Known single-entity/self-closing tags
	$nestable_tags = array('blockquote', 'div', 'span'); //Tags that can be immediately nested within themselves

	# WP bug fix for comments - in case you REALLY meant to type '< !--'
	$text = str_replace('< !--', '<    !--', $text);
	# WP bug fix for LOVE <3 (and other situations with '<' before a number)
	$text = preg_replace('#<([0-9]{1})#', '&lt;$1', $text);

	while (preg_match("/<(\/?\w*)\s*([^>]*)>/",$text,$regex)) {
		$newtext .= $tagqueue;

		$i = strpos($text,$regex[0]);
		$l = strlen($regex[0]);

		// clear the shifter
		$tagqueue = '';
		// Pop or Push
		if ($regex[1][0] == "/") { // End Tag
			$tag = strtolower(substr($regex[1],1));
			// if too many closing tags
			if($stacksize <= 0) {
				$tag = '';
				//or close to be safe $tag = '/' . $tag;
			}
			// if stacktop value = tag close value then pop
			else if ($tagstack[$stacksize - 1] == $tag) { // found closing tag
				$tag = '</' . $tag . '>'; // Close Tag
				// Pop
				array_pop ($tagstack);
				$stacksize--;
			} else { // closing tag not at top, search for it
				for ($j=$stacksize-1;$j>=0;$j--) {
					if ($tagstack[$j] == $tag) {
					// add tag to tagqueue
						for ($k=$stacksize-1;$k>=$j;$k--){
							$tagqueue .= '</' . array_pop ($tagstack) . '>';
							$stacksize--;
						}
						break;
					}
				}
				$tag = '';
			}
		} else { // Begin Tag
			$tag = strtolower($regex[1]);

			// Tag Cleaning

			// If self-closing or '', don't do anything.
			if((substr($regex[2],-1) == '/') || ($tag == '')) {
			}
			// ElseIf it's a known single-entity tag but it doesn't close itself, do so
			elseif ( in_array($tag, $single_tags) ) {
				$regex[2] .= '/';
			} else {	// Push the tag onto the stack
				// If the top of the stack is the same as the tag we want to push, close previous tag
				if (($stacksize > 0) && !in_array($tag, $nestable_tags) && ($tagstack[$stacksize - 1] == $tag)) {
					$tagqueue = '</' . array_pop ($tagstack) . '>';
					$stacksize--;
				}
				$stacksize = array_push ($tagstack, $tag);
			}

			// Attributes
			$attributes = $regex[2];
			if($attributes) {
				$attributes = ' '.$attributes;
			}
			$tag = '<'.$tag.$attributes.'>';
			//If already queuing a close tag, then put this tag on, too
			if ($tagqueue) {
				$tagqueue .= $tag;
				$tag = '';
			}
		}
		$newtext .= substr($text,0,$i) . $tag;
		$text = substr($text,$i+$l);
	}

	// Clear Tag Queue
	$newtext .= $tagqueue;

	// Add Remaining text
	$newtext .= $text;

	// Empty Stack
	while($x = array_pop($tagstack)) {
		$newtext .= '</' . $x . '>'; // Add remaining tags to close
	}

	// WP fix for the bug with HTML comments
	$newtext = str_replace("< !--","<!--",$newtext);
	$newtext = str_replace("<    !--","< !--",$newtext);

	return $newtext;
}

/**
 * Acts on text which is about to be edited.
 *
 * Unless $richedit is set, it is simply a holder for the 'format_to_edit'
 * filter. If $richedit is set true htmlspecialchars() will be run on the
 * content, converting special characters to HTMl entities.
 *
 * @since 0.71
 *
 * @param string $content The text about to be edited.
 * @param bool $richedit Whether or not the $content should pass through htmlspecialchars(). Default false.
 * @return string The text after the filter (and possibly htmlspecialchars()) has been run.
 */
function format_to_edit($content, $richedit = false) {
	$content = apply_filters('format_to_edit', $content);
	if (! $richedit )
		$content = htmlspecialchars($content);
	return $content;
}

/**
 * Holder for the 'format_to_post' filter.
 *
 * @since 0.71
 *
 * @param string $content The text to pass through the filter.
 * @return string Text returned from the 'format_to_post' filter.
 */
function format_to_post($content) {
	$content = apply_filters('format_to_post', $content);
	return $content;
}

/**
 * Add leading zeros when necessary.
 *
 * If you set the threshold to '4' and the number is '10', then you will get
 * back '0010'. If you set the number to '4' and the number is '5000', then you
 * will get back '5000'.
 *
 * Uses sprintf to append the amount of zeros based on the $threshold parameter
 * and the size of the number. If the number is large enough, then no zeros will
 * be appended.
 *
 * @since 0.71
 *
 * @param mixed $number Number to append zeros to if not greater than threshold.
 * @param int $threshold Digit places number needs to be to not have zeros added.
 * @return string Adds leading zeros to number if needed.
 */
function zeroise($number, $threshold) {
	return sprintf('%0'.$threshold.'s', $number);
}

/**
 * Adds backslashes before letters and before a number at the start of a string.
 *
 * @since 0.71
 *
 * @param string $string Value to which backslashes will be added.
 * @return string String with backslashes inserted.
 */
function backslashit($string) {
	$string = preg_replace('/^([0-9])/', '\\\\\\\\\1', $string);
	$string = preg_replace('/([a-z])/i', '\\\\\1', $string);
	return $string;
}

/**
 * Appends a trailing slash.
 *
 * Will remove trailing slash if it exists already before adding a trailing
 * slash. This prevents double slashing a string or path.
 *
 * The primary use of this is for paths and thus should be used for paths. It is
 * not restricted to paths and offers no specific path support.
 *
 * @since 1.2.0
 * @uses untrailingslashit() Unslashes string if it was slashed already.
 *
 * @param string $string What to add the trailing slash to.
 * @return string String with trailing slash added.
 */
function trailingslashit($string) {
	return untrailingslashit($string) . '/';
}

/**
 * Removes trailing slash if it exists.
 *
 * The primary use of this is for paths and thus should be used for paths. It is
 * not restricted to paths and offers no specific path support.
 *
 * @since 2.2.0
 *
 * @param string $string What to remove the trailing slash from.
 * @return string String without the trailing slash.
 */
function untrailingslashit($string) {
	return rtrim($string, '/');
}

/**
 * Adds slashes to escape strings.
 *
 * Slashes will first be removed if magic_quotes_gpc is set, see {@link
 * http://www.php.net/magic_quotes} for more details.
 *
 * @since 0.71
 *
 * @param string $gpc The string returned from HTTP request data.
 * @return string Returns a string escaped with slashes.
 */
function addslashes_gpc($gpc) {
	global $wpdb;

	if (get_magic_quotes_gpc()) {
		$gpc = stripslashes($gpc);
	}

	return $wpdb->escape($gpc);
}

/**
 * Navigates through an array and removes slashes from the values.
 *
 * If an array is passed, the array_map() function causes a callback to pass the
 * value back to the function. The slashes from this value will removed.
 *
 * @since 2.0.0
 *
 * @param array|string $value The array or string to be striped.
 * @return array|string Stripped array (or string in the callback).
 */
function stripslashes_deep($value) {
	$value = is_array($value) ? array_map('stripslashes_deep', $value) : stripslashes($value);
	return $value;
}

/**
 * Navigates through an array and encodes the values to be used in a URL.
 *
 * Uses a callback to pass the value of the array back to the function as a
 * string.
 *
 * @since 2.2.0
 *
 * @param array|string $value The array or string to be encoded.
 * @return array|string $value The encoded array (or string from the callback).
 */
function urlencode_deep($value) {
	$value = is_array($value) ? array_map('urlencode_deep', $value) : urlencode($value);
	return $value;
}

/**
 * Converts email addresses characters to HTML entities to block spam bots.
 *
 * @since 0.71
 *
 * @param string $emailaddy Email address.
 * @param int $mailto Optional. Range from 0 to 1. Used for encoding.
 * @return string Converted email address.
 */
function antispambot($emailaddy, $mailto=0) {
	$emailNOSPAMaddy = '';
	srand ((float) microtime() * 1000000);
	for ($i = 0; $i < strlen($emailaddy); $i = $i + 1) {
		$j = floor(rand(0, 1+$mailto));
		if ($j==0) {
			$emailNOSPAMaddy .= '&#'.ord(substr($emailaddy,$i,1)).';';
		} elseif ($j==1) {
			$emailNOSPAMaddy .= substr($emailaddy,$i,1);
		} elseif ($j==2) {
			$emailNOSPAMaddy .= '%'.zeroise(dechex(ord(substr($emailaddy, $i, 1))), 2);
		}
	}
	$emailNOSPAMaddy = str_replace('@','&#64;',$emailNOSPAMaddy);
	return $emailNOSPAMaddy;
}

/**
 * Callback to convert URI match to HTML A element.
 *
 * This function was backported from 2.5.0 to 2.3.2. Regex callback for {@link
 * make_clickable()}.
 *
 * @since 2.3.2
 * @access private
 *
 * @param array $matches Single Regex Match.
 * @return string HTML A element with URI address.
 */
function _make_url_clickable_cb($matches) {
	$ret = '';
	$url = $matches[2];
	$url = clean_url($url);
	if ( empty($url) )
		return $matches[0];
	// removed trailing [.,;:] from URL
	if ( in_array(substr($url, -1), array('.', ',', ';', ':')) === true ) {
		$ret = substr($url, -1);
		$url = substr($url, 0, strlen($url)-1);
	}
	return $matches[1] . "<a href=\"$url\" rel=\"nofollow\">$url</a>" . $ret;
}

/**
 * Callback to convert URL match to HTML A element.
 *
 * This function was backported from 2.5.0 to 2.3.2. Regex callback for {@link
 * make_clickable()}.
 *
 * @since 2.3.2
 * @access private
 *
 * @param array $matches Single Regex Match.
 * @return string HTML A element with URL address.
 */
function _make_web_ftp_clickable_cb($matches) {
	$ret = '';
	$dest = $matches[2];
	$dest = 'http://' . $dest;
	$dest = clean_url($dest);
	if ( empty($dest) )
		return $matches[0];
	// removed trailing [,;:] from URL
	if ( in_array(substr($dest, -1), array('.', ',', ';', ':')) === true ) {
		$ret = substr($dest, -1);
		$dest = substr($dest, 0, strlen($dest)-1);
	}
	return $matches[1] . "<a href=\"$dest\" rel=\"nofollow\">$dest</a>" . $ret;
}

/**
 * Callback to convert email address match to HTML A element.
 *
 * This function was backported from 2.5.0 to 2.3.2. Regex callback for {@link
 * make_clickable()}.
 *
 * @since 2.3.2
 * @access private
 *
 * @param array $matches Single Regex Match.
 * @return string HTML A element with email address.
 */
function _make_email_clickable_cb($matches) {
	$email = $matches[2] . '@' . $matches[3];
	return $matches[1] . "<a href=\"mailto:$email\">$email</a>";
}

/**
 * Convert plaintext URI to HTML links.
 *
 * Converts URI, www and ftp, and email addresses. Finishes by fixing links
 * within links.
 *
 * @since 0.71
 *
 * @param string $ret Content to convert URIs.
 * @return string Content with converted URIs.
 */
function make_clickable($ret) {
	$ret = ' ' . $ret;
	// in testing, using arrays here was found to be faster
	$ret = preg_replace_callback('#([\s>])([\w]+?://[\w\\x80-\\xff\#$%&~/.\-;:=,?@\[\]+]*)#is', '_make_url_clickable_cb', $ret);
	$ret = preg_replace_callback('#([\s>])((www|ftp)\.[\w\\x80-\\xff\#$%&~/.\-;:=,?@\[\]+]*)#is', '_make_web_ftp_clickable_cb', $ret);
	$ret = preg_replace_callback('#([\s>])([.0-9a-z_+-]+)@(([0-9a-z-]+\.)+[0-9a-z]{2,})#i', '_make_email_clickable_cb', $ret);
	// this one is not in an array because we need it to run last, for cleanup of accidental links within links
	$ret = preg_replace("#(<a( [^>]+?>|>))<a [^>]+?>([^>]+?)</a></a>#i", "$1$3</a>", $ret);
	$ret = trim($ret);
	return $ret;
}

/**
 * Adds rel nofollow string to all HTML A elements in content.
 *
 * @since 1.5.0
 *
 * @param string $text Content that may contain HTML A elements.
 * @return string Converted content.
 */
function wp_rel_nofollow( $text ) {
	global $wpdb;
	// This is a pre save filter, so text is already escaped.
	$text = stripslashes($text);
	$text = preg_replace_callback('|<a (.+?)>|i', 'wp_rel_nofollow_callback', $text);
	$text = $wpdb->escape($text);
	return $text;
}

/**
 * Callback to used to add rel=nofollow string to HTML A element.
 *
 * Will remove already existing rel="nofollow" and rel='nofollow' from the
 * string to prevent from invalidating (X)HTML.
 *
 * @since 2.3.0
 *
 * @param array $matches Single Match
 * @return string HTML A Element with rel nofollow.
 */
function wp_rel_nofollow_callback( $matches ) {
	$text = $matches[1];
	$text = str_replace(array(' rel="nofollow"', " rel='nofollow'"), '', $text);
	return "<a $text rel=\"nofollow\">";
}

/**
 * Convert text equivalent of smilies to images.
 *
 * Will only convert smilies if the option 'use_smilies' is true and the globals
 * used in the function aren't empty.
 *
 * @since 0.71
 * @uses $wp_smiliessearch, $wp_smiliesreplace Smiley replacement arrays.
 *
 * @param string $text Content to convert smilies from text.
 * @return string Converted content with text smilies replaced with images.
 */
function convert_smilies($text) {
	global $wp_smiliessearch, $wp_smiliesreplace;
	$output = '';
	if ( get_option('use_smilies') && !empty($wp_smiliessearch) && !empty($wp_smiliesreplace) ) {
		// HTML loop taken from texturize function, could possible be consolidated
		$textarr = preg_split("/(<.*>)/U", $text, -1, PREG_SPLIT_DELIM_CAPTURE); // capture the tags as well as in between
		$stop = count($textarr);// loop stuff
		for ($i = 0; $i < $stop; $i++) {
			$content = $textarr[$i];
			if ((strlen($content) > 0) && ('<' != $content{0})) { // If it's not a tag
				$content = preg_replace($wp_smiliessearch, $wp_smiliesreplace, $content);
			}
			$output .= $content;
		}
	} else {
		// return default text.
		$output = $text;
	}
	return $output;
}

/**
 * Checks to see if the text is a valid email address.
 *
 * @since 0.71
 *
 * @param string $user_email The email address to be checked.
 * @return bool Returns true if valid, otherwise false.
 */
function is_email($user_email) {
	$chars = "/^([a-z0-9+_]|\\-|\\.)+@(([a-z0-9_]|\\-)+\\.)+[a-z]{2,6}\$/i";
	if (strpos($user_email, '@') !== false && strpos($user_email, '.') !== false) {
		if (preg_match($chars, $user_email)) {
			return true;
		} else {
			return false;
		}
	} else {
		return false;
	}
}

/**
 * Convert to ASCII from email subjects.
 *
 * @since 1.2.0
 * @usedby wp_mail() handles charsets in email subjects
 *
 * @param string $string Subject line
 * @return string Converted string to ASCII
 */
function wp_iso_descrambler($string) {
	/* this may only work with iso-8859-1, I'm afraid */
	if (!preg_match('#\=\?(.+)\?Q\?(.+)\?\=#i', $string, $matches)) {
		return $string;
	} else {
		$subject = str_replace('_', ' ', $matches[2]);
		/** @todo use preg_replace_callback() */
		$subject = preg_replace('#\=([0-9a-f]{2})#ei', "chr(hexdec(strtolower('$1')))", $subject);
		return $subject;
	}
}

/**
 * Returns a date in the GMT equivalent.
 *
 * Requires and returns a date in the Y-m-d H:i:s format. Simply subtracts the
 * value of gmt_offset.
 *
 * @since 1.2.0
 *
 * @param string $string The date to be converted.
 * @return string GMT version of the date provided.
 */
function get_gmt_from_date($string) {
	preg_match('#([0-9]{1,4})-([0-9]{1,2})-([0-9]{1,2}) ([0-9]{1,2}):([0-9]{1,2}):([0-9]{1,2})#', $string, $matches);
	$string_time = gmmktime($matches[4], $matches[5], $matches[6], $matches[2], $matches[3], $matches[1]);
	$string_gmt = gmdate('Y-m-d H:i:s', $string_time - get_option('gmt_offset') * 3600);
	return $string_gmt;
}

/**
 * Converts a GMT date into the correct format for the blog.
 *
 * Requires and returns in the Y-m-d H:i:s format. Simply adds the value of
 * gmt_offset.
 *
 * @since 1.2.0
 *
 * @param string $string The date to be converted.
 * @return string Formatted date relative to the GMT offset.
 */
function get_date_from_gmt($string) {
	preg_match('#([0-9]{1,4})-([0-9]{1,2})-([0-9]{1,2}) ([0-9]{1,2}):([0-9]{1,2}):([0-9]{1,2})#', $string, $matches);
	$string_time = gmmktime($matches[4], $matches[5], $matches[6], $matches[2], $matches[3], $matches[1]);
	$string_localtime = gmdate('Y-m-d H:i:s', $string_time + get_option('gmt_offset')*3600);
	return $string_localtime;
}

/**
 * Computes an offset in seconds from an iso8601 timezone.
 *
 * @since 1.5.0
 *
 * @param string $timezone Either 'Z' for 0 offset or '±hhmm'.
 * @return int|float The offset in seconds.
 */
function iso8601_timezone_to_offset($timezone) {
	// $timezone is either 'Z' or '[+|-]hhmm'
	if ($timezone == 'Z') {
		$offset = 0;
	} else {
		$sign    = (substr($timezone, 0, 1) == '+') ? 1 : -1;
		$hours   = intval(substr($timezone, 1, 2));
		$minutes = intval(substr($timezone, 3, 4)) / 60;
		$offset  = $sign * 3600 * ($hours + $minutes);
	}
	return $offset;
}

/**
 * Converts an iso8601 date to MySQL DateTime format used by post_date[_gmt].
 *
 * @since 1.5.0
 *
 * @param string $date_string Date and time in ISO 8601 format {@link http://en.wikipedia.org/wiki/ISO_8601}.
 * @param string $timezone Optional. If set to GMT returns the time minus gmt_offset. Default is 'user'.
 * @return string The date and time in MySQL DateTime format - Y-m-d H:i:s.
 */
function iso8601_to_datetime($date_string, $timezone = 'user') {
	$timezone = strtolower($timezone);

	if ($timezone == 'gmt') {

		preg_match('#([0-9]{4})([0-9]{2})([0-9]{2})T([0-9]{2}):([0-9]{2}):([0-9]{2})(Z|[\+|\-][0-9]{2,4}){0,1}#', $date_string, $date_bits);

		if (!empty($date_bits[7])) { // we have a timezone, so let's compute an offset
			$offset = iso8601_timezone_to_offset($date_bits[7]);
		} else { // we don't have a timezone, so we assume user local timezone (not server's!)
			$offset = 3600 * get_option('gmt_offset');
		}

		$timestamp = gmmktime($date_bits[4], $date_bits[5], $date_bits[6], $date_bits[2], $date_bits[3], $date_bits[1]);
		$timestamp -= $offset;

		return gmdate('Y-m-d H:i:s', $timestamp);

	} else if ($timezone == 'user') {
		return preg_replace('#([0-9]{4})([0-9]{2})([0-9]{2})T([0-9]{2}):([0-9]{2}):([0-9]{2})(Z|[\+|\-][0-9]{2,4}){0,1}#', '$1-$2-$3 $4:$5:$6', $date_string);
	}
}

/**
 * Adds a element attributes to open links in new windows.
 *
 * Comment text in popup windows should be filtered through this. Right now it's
 * a moderately dumb function, ideally it would detect whether a target or rel
 * attribute was already there and adjust its actions accordingly.
 *
 * @since 0.71
 *
 * @param string $text Content to replace links to open in a new window.
 * @return string Content that has filtered links.
 */
function popuplinks($text) {
	$text = preg_replace('/<a (.+?)>/i', "<a $1 target='_blank' rel='external'>", $text);
	return $text;
}

/**
 * Strips out all characters that are not allowable in an email.
 *
 * @since 1.5.0
 *
 * @param string $email Email address to filter.
 * @return string Filtered email address.
 */
function sanitize_email($email) {
	return preg_replace('/[^a-z0-9+_.@-]/i', '', $email);
}

/**
 * Determines the difference between two timestamps.
 *
 * The difference is returned in a human readable format such as "1 hour",
 * "5 mins", "2 days".
 *
 * @since 1.5.0
 *
 * @param int $from Unix timestamp from which the difference begins.
 * @param int $to Optional. Unix timestamp to end the time difference. Default becomes time() if not set.
 * @return string Human readable time difference.
 */
function human_time_diff( $from, $to = '' ) {
	if ( empty($to) )
		$to = time();
	$diff = (int) abs($to - $from);
	if ($diff <= 3600) {
		$mins = round($diff / 60);
		if ($mins <= 1) {
			$mins = 1;
		}
		$since = sprintf(__ngettext('%s min', '%s mins', $mins), $mins);
	} else if (($diff <= 86400) && ($diff > 3600)) {
		$hours = round($diff / 3600);
		if ($hours <= 1) {
			$hours = 1;
		}
		$since = sprintf(__ngettext('%s hour', '%s hours', $hours), $hours);
	} elseif ($diff >= 86400) {
		$days = round($diff / 86400);
		if ($days <= 1) {
			$days = 1;
		}
		$since = sprintf(__ngettext('%s day', '%s days', $days), $days);
	}
	return $since;
}

/**
 * Generates an excerpt from the content, if needed.
 *
 * The excerpt word amount will be 55 words and if the amount is greater than
 * that, then the string '[...]' will be appended to the excerpt. If the string
 * is less than 55 words, then the content will be returned as is.
 *
 * @since 1.5.0
 *
 * @param string $text The exerpt. If set to empty an excerpt is generated.
 * @return string The excerpt.
 */
function wp_trim_excerpt($text) {
	if ( '' == $text ) {
		$text = get_the_content('');

		$text = strip_shortcodes( $text );

		$text = apply_filters('the_content', $text);
		$text = str_replace(']]>', ']]&gt;', $text);
		$text = strip_tags($text);
		$excerpt_length = apply_filters('excerpt_length', 55);
		$words = explode(' ', $text, $excerpt_length + 1);
		if (count($words) > $excerpt_length) {
			array_pop($words);
			array_push($words, '[...]');
			$text = implode(' ', $words);
		}
	}
	return $text;
}

/**
 * Converts named entities into numbered entities.
 *
 * @since 1.5.1
 *
 * @param string $text The text within which entities will be converted.
 * @return string Text with converted entities.
 */
function ent2ncr($text) {
	$to_ncr = array(
		'&quot;' => '&#34;',
		'&amp;' => '&#38;',
		'&frasl;' => '&#47;',
		'&lt;' => '&#60;',
		'&gt;' => '&#62;',
		'|' => '&#124;',
		'&nbsp;' => '&#160;',
		'&iexcl;' => '&#161;',
		'&cent;' => '&#162;',
		'&pound;' => '&#163;',
		'&curren;' => '&#164;',
		'&yen;' => '&#165;',
		'&brvbar;' => '&#166;',
		'&brkbar;' => '&#166;',
		'&sect;' => '&#167;',
		'&uml;' => '&#168;',
		'&die;' => '&#168;',
		'&copy;' => '&#169;',
		'&ordf;' => '&#170;',
		'&laquo;' => '&#171;',
		'&not;' => '&#172;',
		'&shy;' => '&#173;',
		'&reg;' => '&#174;',
		'&macr;' => '&#175;',
		'&hibar;' => '&#175;',
		'&deg;' => '&#176;',
		'&plusmn;' => '&#177;',
		'&sup2;' => '&#178;',
		'&sup3;' => '&#179;',
		'&acute;' => '&#180;',
		'&micro;' => '&#181;',
		'&para;' => '&#182;',
		'&middot;' => '&#183;',
		'&cedil;' => '&#184;',
		'&sup1;' => '&#185;',
		'&ordm;' => '&#186;',
		'&raquo;' => '&#187;',
		'&frac14;' => '&#188;',
		'&frac12;' => '&#189;',
		'&frac34;' => '&#190;',
		'&iquest;' => '&#191;',
		'&Agrave;' => '&#192;',
		'&Aacute;' => '&#193;',
		'&Acirc;' => '&#194;',
		'&Atilde;' => '&#195;',
		'&Auml;' => '&#196;',
		'&Aring;' => '&#197;',
		'&AElig;' => '&#198;',
		'&Ccedil;' => '&#199;',
		'&Egrave;' => '&#200;',
		'&Eacute;' => '&#201;',
		'&Ecirc;' => '&#202;',
		'&Euml;' => '&#203;',
		'&Igrave;' => '&#204;',
		'&Iacute;' => '&#205;',
		'&Icirc;' => '&#206;',
		'&Iuml;' => '&#207;',
		'&ETH;' => '&#208;',
		'&Ntilde;' => '&#209;',
		'&Ograve;' => '&#210;',
		'&Oacute;' => '&#211;',
		'&Ocirc;' => '&#212;',
		'&Otilde;' => '&#213;',
		'&Ouml;' => '&#214;',
		'&times;' => '&#215;',
		'&Oslash;' => '&#216;',
		'&Ugrave;' => '&#217;',
		'&Uacute;' => '&#218;',
		'&Ucirc;' => '&#219;',
		'&Uuml;' => '&#220;',
		'&Yacute;' => '&#221;',
		'&THORN;' => '&#222;',
		'&szlig;' => '&#223;',
		'&agrave;' => '&#224;',
		'&aacute;' => '&#225;',
		'&acirc;' => '&#226;',
		'&atilde;' => '&#227;',
		'&auml;' => '&#228;',
		'&aring;' => '&#229;',
		'&aelig;' => '&#230;',
		'&ccedil;' => '&#231;',
		'&egrave;' => '&#232;',
		'&eacute;' => '&#233;',
		'&ecirc;' => '&#234;',
		'&euml;' => '&#235;',
		'&igrave;' => '&#236;',
		'&iacute;' => '&#237;',
		'&icirc;' => '&#238;',
		'&iuml;' => '&#239;',
		'&eth;' => '&#240;',
		'&ntilde;' => '&#241;',
		'&ograve;' => '&#242;',
		'&oacute;' => '&#243;',
		'&ocirc;' => '&#244;',
		'&otilde;' => '&#245;',
		'&ouml;' => '&#246;',
		'&divide;' => '&#247;',
		'&oslash;' => '&#248;',
		'&ugrave;' => '&#249;',
		'&uacute;' => '&#250;',
		'&ucirc;' => '&#251;',
		'&uuml;' => '&#252;',
		'&yacute;' => '&#253;',
		'&thorn;' => '&#254;',
		'&yuml;' => '&#255;',
		'&OElig;' => '&#338;',
		'&oelig;' => '&#339;',
		'&Scaron;' => '&#352;',
		'&scaron;' => '&#353;',
		'&Yuml;' => '&#376;',
		'&fnof;' => '&#402;',
		'&circ;' => '&#710;',
		'&tilde;' => '&#732;',
		'&Alpha;' => '&#913;',
		'&Beta;' => '&#914;',
		'&Gamma;' => '&#915;',
		'&Delta;' => '&#916;',
		'&Epsilon;' => '&#917;',
		'&Zeta;' => '&#918;',
		'&Eta;' => '&#919;',
		'&Theta;' => '&#920;',
		'&Iota;' => '&#921;',
		'&Kappa;' => '&#922;',
		'&Lambda;' => '&#923;',
		'&Mu;' => '&#924;',
		'&Nu;' => '&#925;',
		'&Xi;' => '&#926;',
		'&Omicron;' => '&#927;',
		'&Pi;' => '&#928;',
		'&Rho;' => '&#929;',
		'&Sigma;' => '&#931;',
		'&Tau;' => '&#932;',
		'&Upsilon;' => '&#933;',
		'&Phi;' => '&#934;',
		'&Chi;' => '&#935;',
		'&Psi;' => '&#936;',
		'&Omega;' => '&#937;',
		'&alpha;' => '&#945;',
		'&beta;' => '&#946;',
		'&gamma;' => '&#947;',
		'&delta;' => '&#948;',
		'&epsilon;' => '&#949;',
		'&zeta;' => '&#950;',
		'&eta;' => '&#951;',
		'&theta;' => '&#952;',
		'&iota;' => '&#953;',
		'&kappa;' => '&#954;',
		'&lambda;' => '&#955;',
		'&mu;' => '&#956;',
		'&nu;' => '&#957;',
		'&xi;' => '&#958;',
		'&omicron;' => '&#959;',
		'&pi;' => '&#960;',
		'&rho;' => '&#961;',
		'&sigmaf;' => '&#962;',
		'&sigma;' => '&#963;',
		'&tau;' => '&#964;',
		'&upsilon;' => '&#965;',
		'&phi;' => '&#966;',
		'&chi;' => '&#967;',
		'&psi;' => '&#968;',
		'&omega;' => '&#969;',
		'&thetasym;' => '&#977;',
		'&upsih;' => '&#978;',
		'&piv;' => '&#982;',
		'&ensp;' => '&#8194;',
		'&emsp;' => '&#8195;',
		'&thinsp;' => '&#8201;',
		'&zwnj;' => '&#8204;',
		'&zwj;' => '&#8205;',
		'&lrm;' => '&#8206;',
		'&rlm;' => '&#8207;',
		'&ndash;' => '&#8211;',
		'&mdash;' => '&#8212;',
		'&lsquo;' => '&#8216;',
		'&rsquo;' => '&#8217;',
		'&sbquo;' => '&#8218;',
		'&ldquo;' => '&#8220;',
		'&rdquo;' => '&#8221;',
		'&bdquo;' => '&#8222;',
		'&dagger;' => '&#8224;',
		'&Dagger;' => '&#8225;',
		'&bull;' => '&#8226;',
		'&hellip;' => '&#8230;',
		'&permil;' => '&#8240;',
		'&prime;' => '&#8242;',
		'&Prime;' => '&#8243;',
		'&lsaquo;' => '&#8249;',
		'&rsaquo;' => '&#8250;',
		'&oline;' => '&#8254;',
		'&frasl;' => '&#8260;',
		'&euro;' => '&#8364;',
		'&image;' => '&#8465;',
		'&weierp;' => '&#8472;',
		'&real;' => '&#8476;',
		'&trade;' => '&#8482;',
		'&alefsym;' => '&#8501;',
		'&crarr;' => '&#8629;',
		'&lArr;' => '&#8656;',
		'&uArr;' => '&#8657;',
		'&rArr;' => '&#8658;',
		'&dArr;' => '&#8659;',
		'&hArr;' => '&#8660;',
		'&forall;' => '&#8704;',
		'&part;' => '&#8706;',
		'&exist;' => '&#8707;',
		'&empty;' => '&#8709;',
		'&nabla;' => '&#8711;',
		'&isin;' => '&#8712;',
		'&notin;' => '&#8713;',
		'&ni;' => '&#8715;',
		'&prod;' => '&#8719;',
		'&sum;' => '&#8721;',
		'&minus;' => '&#8722;',
		'&lowast;' => '&#8727;',
		'&radic;' => '&#8730;',
		'&prop;' => '&#8733;',
		'&infin;' => '&#8734;',
		'&ang;' => '&#8736;',
		'&and;' => '&#8743;',
		'&or;' => '&#8744;',
		'&cap;' => '&#8745;',
		'&cup;' => '&#8746;',
		'&int;' => '&#8747;',
		'&there4;' => '&#8756;',
		'&sim;' => '&#8764;',
		'&cong;' => '&#8773;',
		'&asymp;' => '&#8776;',
		'&ne;' => '&#8800;',
		'&equiv;' => '&#8801;',
		'&le;' => '&#8804;',
		'&ge;' => '&#8805;',
		'&sub;' => '&#8834;',
		'&sup;' => '&#8835;',
		'&nsub;' => '&#8836;',
		'&sube;' => '&#8838;',
		'&supe;' => '&#8839;',
		'&oplus;' => '&#8853;',
		'&otimes;' => '&#8855;',
		'&perp;' => '&#8869;',
		'&sdot;' => '&#8901;',
		'&lceil;' => '&#8968;',
		'&rceil;' => '&#8969;',
		'&lfloor;' => '&#8970;',
		'&rfloor;' => '&#8971;',
		'&lang;' => '&#9001;',
		'&rang;' => '&#9002;',
		'&larr;' => '&#8592;',
		'&uarr;' => '&#8593;',
		'&rarr;' => '&#8594;',
		'&darr;' => '&#8595;',
		'&harr;' => '&#8596;',
		'&loz;' => '&#9674;',
		'&spades;' => '&#9824;',
		'&clubs;' => '&#9827;',
		'&hearts;' => '&#9829;',
		'&diams;' => '&#9830;'
	);

	return str_replace( array_keys($to_ncr), array_values($to_ncr), $text );
}

/**
 * Formats text for the rich text editor.
 *
 * The filter 'richedit_pre' is applied here. If $text is empty the filter will
 * be applied to an empty string.
 *
 * @since 2.0.0
 *
 * @param string $text The text to be formatted.
 * @return string The formatted text after filter is applied.
 */
function wp_richedit_pre($text) {
	// Filtering a blank results in an annoying <br />\n
	if ( empty($text) ) return apply_filters('richedit_pre', '');

	$output = convert_chars($text);
	$output = wpautop($output);
	$output = htmlspecialchars($output, ENT_NOQUOTES);

	return apply_filters('richedit_pre', $output);
}

/**
 * Formats text for the HTML editor.
 *
 * Unless $output is empty it will pass through htmlspecialchars before the
 * 'htmledit_pre' filter is applied.
 *
 * @since 2.5.0
 *
 * @param string $output The text to be formatted.
 * @return string Formatted text after filter applied.
 */
function wp_htmledit_pre($output) {
	if ( !empty($output) )
		$output = htmlspecialchars($output, ENT_NOQUOTES); // convert only < > &

	return apply_filters('htmledit_pre', $output);
}

/**
 * Checks and cleans a URL.
 *
 * A number of characters are removed from the URL. If the URL is for displaying
 * (the default behaviour) amperstands are also replaced. The 'clean_url' filter
 * is applied to the returned cleaned URL.
 *
 * @since 1.2.0
 * @uses wp_kses_bad_protocol() To only permit protocols in the URL set
 *		via $protocols or the common ones set in the function.
 *
 * @param string $url The URL to be cleaned.
 * @param array $protocols Optional. An array of acceptable protocols.
 *		Defaults to 'http', 'https', 'ftp', 'ftps', 'mailto', 'news', 'irc', 'gopher', 'nntp', 'feed', 'telnet' if not set.
 * @param string $context Optional. How the URL will be used. Default is 'display'.
 * @return string The cleaned $url after the 'cleaned_url' filter is applied.
 */
function clean_url( $url, $protocols = null, $context = 'display' ) {
	$original_url = $url;

	if ('' == $url) return $url;
	$url = preg_replace('|[^a-z0-9-~+_.?#=!&;,/:%@$*\'()\\x80-\\xff]|i', '', $url);
	$strip = array('%0d', '%0a');
	$url = str_replace($strip, '', $url);
	$url = str_replace(';//', '://', $url);
	/* If the URL doesn't appear to contain a scheme, we
	 * presume it needs http:// appended (unless a relative
	 * link starting with / or a php file).
	 */
	if ( strpos($url, ':') === false &&
		substr( $url, 0, 1 ) != '/' && !preg_match('/^[a-z0-9-]+?\.php/i', $url) )
		$url = 'http://' . $url;

	// Replace ampersands and single quotes only when displaying.
	if ( 'display' == $context ) {
		$url = preg_replace('/&([^#])(?![a-z]{2,8};)/', '&#038;$1', $url);
		$url = str_replace( "'", '&#039;', $url );
	}

	if ( !is_array($protocols) )
		$protocols = array('http', 'https', 'ftp', 'ftps', 'mailto', 'news', 'irc', 'gopher', 'nntp', 'feed', 'telnet');
	if ( wp_kses_bad_protocol( $url, $protocols ) != $url )
		return '';

	return apply_filters('clean_url', $url, $original_url, $context);
}

/**
 * Performs clean_url() for database usage.
 *
 * @see clean_url()
 *
 * @since 2.3.1
 *
 * @param string $url The URL to be cleaned.
 * @param array $protocols An array of acceptable protocols.
 * @return string The cleaned URL.
 */
function sanitize_url( $url, $protocols = null ) {
	return clean_url( $url, $protocols, 'db' );
}

/**
 * Convert entities, while preserving already-encoded entities.
 *
 * @link http://www.php.net/htmlentities Borrowed from the PHP Manual user notes.
 *
 * @since 1.2.2
 *
 * @param string $myHTML The text to be converted.
 * @return string Converted text.
 */
function htmlentities2($myHTML) {
	$translation_table = get_html_translation_table( HTML_ENTITIES, ENT_QUOTES );
	$translation_table[chr(38)] = '&';
	return preg_replace( "/&(?![A-Za-z]{0,4}\w{2,3};|#[0-9]{2,3};)/", "&amp;", strtr($myHTML, $translation_table) );
}

/**
 * Escape single quotes, specialchar double quotes, and fix line endings.
 *
 * The filter 'js_escape' is also applied here.
 *
 * @since 2.0.4
 *
 * @param string $text The text to be escaped.
 * @return string Escaped text.
 */
function js_escape($text) {
	$safe_text = wp_specialchars($text, 'double');
	$safe_text = preg_replace('/&#(x)?0*(?(1)27|39);?/i', "'", stripslashes($safe_text));
	$safe_text = preg_replace("/\r?\n/", "\\n", addslashes($safe_text));
	return apply_filters('js_escape', $safe_text, $text);
}

/**
 * Escaping for HTML attributes.
 *
 * @since 2.0.6
 *
 * @param string $text
 * @return string
 */
function attribute_escape($text) {
	$safe_text = wp_specialchars($text, true);
	return apply_filters('attribute_escape', $safe_text, $text);
}

/**
 * Escape a HTML tag name.
 *
 * @since 2.5.0
 *
 * @param string $tag_name
 * @return string
 */
function tag_escape($tag_name) {
	$safe_tag = strtolower( preg_replace('[^a-zA-Z_:]', '', $tag_name) );
	return apply_filters('tag_escape', $safe_tag, $tag_name);
}

/**
 * Escapes text for SQL LIKE special characters % and _.
 *
 * @since 2.5.0
 *
 * @param string $text The text to be escaped.
 * @return string text, safe for inclusion in LIKE query.
 */
function like_escape($text) {
	return str_replace(array("%", "_"), array("\\%", "\\_"), $text);
}

/**
 * Convert full URL paths to absolute paths.
 *
 * Removes the http or https protocols and the domain. Keeps the path '/' at the
 * beginning, so it isn't a true relative link, but from the web root base.
 *
 * @since 2.1.0
 *
 * @param string $link Full URL path.
 * @return string Absolute path.
 */
function wp_make_link_relative( $link ) {
	return preg_replace( '|https?://[^/]+(/.*)|i', '$1', $link );
}

/**
 * Sanitises various option values based on the nature of the option.
 *
 * This is basically a switch statement which will pass $value through a number
 * of functions depending on the $option.
 *
 * @since 2.0.5
 *
 * @param string $option The name of the option.
 * @param string $value The unsanitised value.
 * @return string Sanitized value.
 */
function sanitize_option($option, $value) {

	switch ($option) {
		case 'admin_email':
			$value = sanitize_email($value);
			break;

		case 'thumbnail_size_w':
		case 'thumbnail_size_h':
		case 'medium_size_w':
		case 'medium_size_h':
		case 'large_size_w':
		case 'large_size_h':
		case 'default_post_edit_rows':
		case 'mailserver_port':
		case 'comment_max_links':
		case 'page_on_front':
		case 'rss_excerpt_length':
		case 'default_category':
		case 'default_email_category':
		case 'default_link_category':
		case 'close_comments_days_old':
		case 'comments_per_page':
		case 'thread_comments_depth':
			$value = abs((int) $value);
			break;

		case 'posts_per_page':
		case 'posts_per_rss':
			$value = (int) $value;
			if ( empty($value) ) $value = 1;
			if ( $value < -1 ) $value = abs($value);
			break;

		case 'default_ping_status':
		case 'default_comment_status':
			// Options that if not there have 0 value but need to be something like "closed"
			if ( $value == '0' || $value == '')
				$value = 'closed';
			break;

		case 'blogdescription':
		case 'blogname':
			$value = addslashes($value);
			$value = wp_filter_post_kses( $value ); // calls stripslashes then addslashes
			$value = stripslashes($value);
			$value = wp_specialchars( $value );
			break;

		case 'blog_charset':
			$value = preg_replace('/[^a-zA-Z0-9_-]/', '', $value); // strips slashes
			break;

		case 'date_format':
		case 'time_format':
		case 'mailserver_url':
		case 'mailserver_login':
		case 'mailserver_pass':
		case 'ping_sites':
		case 'upload_path':
			$value = strip_tags($value);
			$value = addslashes($value);
			$value = wp_filter_kses($value); // calls stripslashes then addslashes
			$value = stripslashes($value);
			break;

		case 'gmt_offset':
			$value = preg_replace('/[^0-9:.-]/', '', $value); // strips slashes
			break;

		case 'siteurl':
		case 'home':
			$value = stripslashes($value);
			$value = clean_url($value);
			break;
		default :
			$value = apply_filters("sanitize_option_{$option}", $value, $option);
			break;
	}

	return $value;
}

/**
 * Parses a string into variables to be stored in an array.
 *
 * Uses {@link http://www.php.net/parse_str parse_str()} and stripslashes if
 * {@link http://www.php.net/magic_quotes magic_quotes_gpc} is on.
 *
 * @since 2.2.1
 * @uses apply_filters() for the 'wp_parse_str' filter.
 *
 * @param string $string The string to be parsed.
 * @param array $array Variables will be stored in this array.
 */
function wp_parse_str( $string, &$array ) {
	parse_str( $string, $array );
	if ( get_magic_quotes_gpc() )
		$array = stripslashes_deep( $array );
	$array = apply_filters( 'wp_parse_str', $array );
}

/**
 * Convert lone less than signs.
 *
 * KSES already converts lone greater than signs.
 *
 * @uses wp_pre_kses_less_than_callback in the callback function.
 * @since 2.3.0
 *
 * @param string $text Text to be converted.
 * @return string Converted text.
 */
function wp_pre_kses_less_than( $text ) {
	return preg_replace_callback('%<[^>]*?((?=<)|>|$)%', 'wp_pre_kses_less_than_callback', $text);
}

/**
 * Callback function used by preg_replace.
 *
 * @uses wp_specialchars to format the $matches text.
 * @since 2.3.0
 *
 * @param array $matches Populated by matches to preg_replace.
 * @return string The text returned after wp_specialchars if needed.
 */
function wp_pre_kses_less_than_callback( $matches ) {
	if ( false === strpos($matches[0], '>') )
		return wp_specialchars($matches[0]);
	return $matches[0];
}

/**
 * WordPress implementation of PHP sprintf() with filters.
 *
 * @since 2.5.0
 * @link http://www.php.net/sprintf
 *
 * @param string $pattern The string which formatted args are inserted.
 * @param mixed $args,... Arguments to be formatted into the $pattern string.
 * @return string The formatted string.
 */
function wp_sprintf( $pattern ) {
	$args = func_get_args( );
	$len = strlen($pattern);
	$start = 0;
	$result = '';
	$arg_index = 0;
	while ( $len > $start ) {
		// Last character: append and break
		if ( strlen($pattern) - 1 == $start ) {
			$result .= substr($pattern, -1);
			break;
		}

		// Literal %: append and continue
		if ( substr($pattern, $start, 2) == '%%' ) {
			$start += 2;
			$result .= '%';
			continue;
		}

		// Get fragment before next %
		$end = strpos($pattern, '%', $start + 1);
		if ( false === $end )
			$end = $len;
		$fragment = substr($pattern, $start, $end - $start);

		// Fragment has a specifier
		if ( $pattern{$start} == '%' ) {
			// Find numbered arguments or take the next one in order
			if ( preg_match('/^%(\d+)\$/', $fragment, $matches) ) {
				$arg = isset($args[$matches[1]]) ? $args[$matches[1]] : '';
				$fragment = str_replace("%{$matches[1]}$", '%', $fragment);
			} else {
				++$arg_index;
				$arg = isset($args[$arg_index]) ? $args[$arg_index] : '';
			}

			// Apply filters OR sprintf
			$_fragment = apply_filters( 'wp_sprintf', $fragment, $arg );
			if ( $_fragment != $fragment )
				$fragment = $_fragment;
			else
				$fragment = sprintf($fragment, strval($arg) );
		}

		// Append to result and move to next fragment
		$result .= $fragment;
		$start = $end;
	}
	return $result;
}

/**
 * Localize list items before the rest of the content.
 *
 * The '%l' must be at the first characters can then contain the rest of the
 * content. The list items will have ', ', ', and', and ' and ' added depending
 * on the amount of list items in the $args parameter.
 *
 * @since 2.5.0
 *
 * @param string $pattern Content containing '%l' at the beginning.
 * @param array $args List items to prepend to the content and replace '%l'.
 * @return string Localized list items and rest of the content.
 */
function wp_sprintf_l($pattern, $args) {
	// Not a match
	if ( substr($pattern, 0, 2) != '%l' )
		return $pattern;

	// Nothing to work with
	if ( empty($args) )
		return '';

	// Translate and filter the delimiter set (avoid ampersands and entities here)
	$l = apply_filters('wp_sprintf_l', array(
		'between'          => _c(', |between list items'),
		'between_last_two' => _c(', and |between last two list items'),
		'between_only_two' => _c(' and |between only two list items'),
		));

	$args = (array) $args;
	$result = array_shift($args);
	if ( count($args) == 1 )
		$result .= $l['between_only_two'] . array_shift($args);
	// Loop when more than two args
	$i = count($args);
	while ( $i ) {
		$arg = array_shift($args);
		$i--;
		if ( $i == 1 )
			$result .= $l['between_last_two'] . $arg;
		else
			$result .= $l['between'] . $arg;
	}
	return $result . substr($pattern, 2);
}

/**
 * Safely extracts not more than the first $count characters from html string.
 *
 * UTF-8, tags and entities safe prefix extraction. Entities inside will *NOT*
 * be counted as one character. For example &amp; will be counted as 4, &lt; as
 * 3, etc.
 *
 * @since 2.5.0
 *
 * @param integer $str String to get the excerpt from.
 * @param integer $count Maximum number of characters to take.
 * @return string The excerpt.
 */
function wp_html_excerpt( $str, $count ) {
	$str = strip_tags( $str );
	$str = mb_strcut( $str, 0, $count );
	// remove part of an entity at the end
	$str = preg_replace( '/&[^;\s]{0,6}$/', '', $str );
	return $str;
}

/**
 * Add a Base url to relative links in passed content.
 *
 * By default it supports the 'src' and 'href' attributes. However this can be
 * changed via the 3rd param.
 *
 * @since 2.7.0
 *
 * @param string $content String to search for links in.
 * @param string $base The base URL to prefix to links.
 * @param array $attrs The attributes which should be processed.
 * @return string The processed content.
 */
function links_add_base_url( $content, $base, $attrs = array('src', 'href') ) {
	$attrs = implode('|', (array)$attrs);
	return preg_replace_callback("!($attrs)=(['\"])(.+?)\\2!i",
			create_function('$m', 'return _links_add_base($m, "' . $base . '");'),
			$content);
}

/**
 * Callback to add a base url to relative links in passed content.
 *
 * @since 2.7.0
 * @access private
 *
 * @param string $m The matched link.
 * @param string $base The base URL to prefix to links.
 * @return string The processed link.
 */
function _links_add_base($m, $base) {
	//1 = attribute name  2 = quotation mark  3 = URL
	return $m[1] . '=' . $m[2] .
		(strpos($m[3], 'http://') === false ?
			path_join($base, $m[3]) :
			$m[3])
		. $m[2];
}

/**
 * Adds a Target attribute to all links in passed content.
 *
 * This function by default only applies to <a> tags, however this can be
 * modified by the 3rd param.
 *
 * <b>NOTE:</b> Any current target attributed will be striped and replaced.
 *
 * @since 2.7.0
 *
 * @param string $content String to search for links in.
 * @param string $target The Target to add to the links.
 * @param array $tags An array of tags to apply to.
 * @return string The processed content.
 */
function links_add_target( $content, $target = '_blank', $tags = array('a') ) {
	$tags = implode('|', (array)$tags);
	return preg_replace_callback("!<($tags)(.+?)>!i",
			create_function('$m', 'return _links_add_target($m, "' . $target . '");'),
			$content);
}
/**
 * Callback to add a target attribute to all links in passed content.
 *
 * @since 2.7.0
 * @access private
 *
 * @param string $m The matched link.
 * @param string $target The Target to add to the links.
 * @return string The processed link.
 */
function _links_add_target( $m, $target ) {
	$tag = $m[1];
	$link = preg_replace('|(target=[\'"](.*?)[\'"])|i', '', $m[2]);
	return '<' . $tag . $link . ' target="' . $target . '">';
}

// normalize EOL characters and strip duplicate whitespace
function normalize_whitespace( $str ) {
	$str  = trim($str);
	$str  = str_replace("\r", "\n", $str);
	$str  = preg_replace( array( '/\n+/', '/[ \t]+/' ), array( "\n", ' ' ), $str );
	return $str;
}

?>
