php中高性能中文字符串截取函数分享

这是用了phpwind里面的一个字符串截取函数，他支持gbk,gbk2312,utf-8等多种编码的字符截取，也很好高效的支持中文字符串的处理。

代码如下

复制代码

function substrs($content,$length,$add='Y'){ if (strlen($content)>$length) { if ($GLOBALS['db_charset']!='utf-8') { $retstr = ''; for ($i=0;$i$retstr .= ord($content[$i]) > 127 ? $content[$i].$content[++$i] : $content[$i]; } return $retstr.($add=='Y' ? ' ..' : ''); } return utf8_trim(substr($content,0,$length)).($add=='Y' ? ' ..' : ''); } return $content; } function utf8_trim($str) { $hex = ''; $len = strlen($str)-1; for ($i=$len;$i>=0;$i-=1) { $ch = ord($str[$i]); $hex .= " $ch"; if (($ch & 128)==0 || ($ch & 192)==192) { return substr($str,0,$i); } } return $str.$hex; } function cutstr($string, $length, $dot = ' ...') { global $charset; if(strlen($string) return $string; } $string = str_replace(array('&', '"', ''), array('&', '"', ''), $string); $strcut = ''; if(strtolower($charset) == 'utf-8') { $n = $tn = $noc = 0; while($n $t = ord($string[$n]); if($t == 9 || $t == 10 || (32 $tn = 1; $n++; $noc++; } elseif(194 $tn = 2; $n += 2; $noc += 2; } elseif(224 $tn = 3; $n += 3; $noc += 2; } elseif(240 $tn = 4; $n += 4; $noc += 2; } elseif(248 $tn = 5; $n += 5; $noc += 2; } elseif($t == 252 || $t == 253) { $tn = 6; $n += 6; $noc += 2; } else { $n++; } if($noc >= $length) { break; } } if($noc > $length) { $n -= $tn; } $strcut = substr($string, 0, $n); } else { for($i = 0; $i $strcut .= ord($string[$i]) > 127 ? $string[$i].$string[++$i] : $string[$i]; } } $strcut = str_replace(array('&', '"', ''), array('&', '"', ''), $strcut); return $strcut.$dot; }