分享一个截取指定长度字符串的函数，可以对字符串指定要截取的长度，并可以设置超出部分的显示内容，很不错，值得借鉴与学习。
根据中文裁减字符串，截取指定长度的字串内容。
代码如下：
'),array($pre . '&'. $end, $pre . '"' . $end, $pre . '' . $end),
$string);
$strcut = '';
if (strtolower(CHARSET) == 'utf-8'){
$n = $tn =$noc = 0;
while ($n< strlen($string)) {
$t =ord($string[$n]);
if ($t == 9 || $t == 10 || (32<= $t && $t <= 126)) {
$tn = 1;
$n++;
$noc++;
} elseif (194 <= $t&& $t <= 223) {
$tn = 2;
$n += 2;
$noc += 2;
} elseif (224 <= $t&& $t <= 239) {
$tn = 3;
$n += 3;
$noc += 2;
} elseif (240 <= $t&& $t <= 247) {
$tn = 4;
$n += 4;
$noc += 2;
} elseif (248 <= $t&& $t <= 251) {
$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 < $length; $i++) {
$strcut .= ord($string[$i])> 127 ? $string[$i] . $string[++$i] : $string[$i];
}
}
$strcut = str_replace(array($pre . '&' .$end, $pre . '"' . $end, $pre . '' .$end), array('&', '"',''),
$strcut);
$pos = strrpos($strcut, chr(1));
if ($pos !== false) {
$strcut =substr($strcut, 0, $pos);
}
return $strcut . $dot;
}
?>
