1. 截取GB2312中文字符串

<?php

< ?php 

//截取中文字符串

function mysubstr($str, $start, $len) {

    $tmpstr = "";

    $strlen = $start + $len;

    for($i = 0; $i < $strlen; $i++) {

        if(ord(substr($str, $i, 1)) > 0xa0) {

            $tmpstr .= substr($str, $i, 2);

            $i++;

        } else

            $tmpstr .= substr($str, $i, 1);

    }

    return $tmpstr;

}

?>

2. 截取utf8编码的多字节字符串

<?php

< ?php

//截取utf8字符串

function utf8Substr($str, $from, $len)

{

    return preg_replace('#^(?:[\x00-\x7F]|[\xC0-\xFF][\x80-\xBF]+){0,'.$from.'}'.

                       '((?:[\x00-\x7F]|[\xC0-\xFF][\x80-\xBF]+){0,'.$len.'}).*#s',

                       '$1',$str);

}

?>

3. UTF-8、GB2312都支持的汉字截取函数

<?php

< ?php

/* 

Utf-8、gb2312都支持的汉字截取函数 

cut_str(字符串, 截取长度, 开始长度, 编码); 

编码默认为 utf-8 

开始长度默认为 0 

*/ 

 

function cut_str($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; 

    } 

} 

 

$str = "abcd需要截取的字符串"; 

echo cut_str($str, 8, 0, 'gb2312'); 

?>

4. BugFree 的字符截取函数

<?php

< ?php 

/** 

 * @package     BugFree 

 * @version     $Id: FunctionsMain.inc.php,v 1.32 2005/09/24 11:38:37 wwccss Exp $ 

 * 

 * 

 * Return part of a string(Enhance the function substr()) 

 * 

 * @author                  Chunsheng Wang <> 

 * @param string  $String  the string to cut. 

 * @param int     $Length  the length of returned string. 

 * @param booble  $Append  whether append "...": false|true 

 * @return string           the cutted string. 

 */ 

function sysSubStr($String,$Length,$Append = false) 

{ 

    if (strlen($String) < = $Length ) 

    { 

        return $String; 

    } 

    else 

    { 

        $I = 0; 

        while ($I < $Length) 

        { 

            $StringTMP = substr($String,$I,1); 

            if ( ord($StringTMP) >=224 ) 

            { 

                $StringTMP = substr($String,$I,3); 

                $I = $I + 3; 

            } 

            elseif( ord($StringTMP) >=192 ) 

            { 

                $StringTMP = substr($String,$I,2); 

                $I = $I + 2; 

            } 

            else 

            { 

                $I = $I + 1; 

            } 

            $StringLast[] = $StringTMP; 

        } 

        $StringLast = implode("",$StringLast); 

        if($Append) 

        { 

            $StringLast .= "..."; 

        } 

        return $StringLast; 

    } 

} 

 

$String = "CodeBit.cn -- 简单、精彩、通用"; 

$Length = "18"; 

$Append = false; 

echo sysSubStr($String,$Length,$Append); 

?>