截取中文字符串

[php]代码库

/**
*
* 中文字符串截取
* @param string $string
* @param int $sublen
* @param int $start
* @param string $code
*/
function substr_zh ( $string, $sublen, $start = 0, $code = 'UTF-8' )
{
	if ( $code == 'UTF-8' )
	{
		$pa = "/[\x01-\x7f]|[\xc2-\xdf][\x80-\xbf]|\xe0[\xa0-\xbf][\x80-\xbf]|[\xe1-\xef][\x80-\xbf][\x80-\xbf]|\xf0[\x90-\xbf][\x80-\xbf][\x80-\xbf]|[\xf1-\xf7][\x80-\xbf][\x80-\xbf][\x80-\xbf]/";
		preg_match_all ( $pa, $string, $t_string );

		if ( count ( $t_string[0] ) - $start > $sublen ) return join ( '', array_slice ( $t_string[0], $start, $sublen ) ) . "...";
		return join ( '', array_slice ( $t_string[0], $start, $sublen ) );
	}
	else
	{
		$start = $start * 2;
		$sublen = $sublen * 2;
		$strlen = strlen ( $string );
		$tmpstr = '';

		for ( $i = 0; $i < $strlen; $i ++ )
		{
			if ( $i >= $start && $i < ( $start + $sublen ) )
			{
				if ( ord ( substr ( $string, $i, 1 ) ) > 129 )
				{
					$tmpstr .= substr ( $string, $i, 2 );
				}
				else
				{
					$tmpstr .= substr ( $string, $i, 1 );
				}
			}
			if ( ord ( substr ( $string, $i, 1 ) ) > 129 ) $i ++;
		}
		if ( strlen ( $tmpstr ) < $strlen ) $tmpstr .= "...";
		return $tmpstr;
	}
}