PHP 截取字符串 分别适合GB2312和UTF8编码情况

1. 截取GB2312中文字符串 复制代码 代码如下:function mysubstr($str, $start, $len) { $tmpstr = ""; $strlen = $start + $len; for($i = 0; $i if(ord(substr($str, $i, 1)) > 0xa0) { $tmpstr .= substr($str, $i, 2); $i++; } else $tmpstr .= substr($str, $i, 1); } return $tmpstr; } ?> 2. 截取utf8编码的多字节字符串 复制代码 代码如下:function utf8Substr($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 复制代码 代码如下: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; $i{ if($i>=$start && $i{ if(ord(substr($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)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 复制代码 代码如下:* @package BugFree * @version $Id: FunctionsMain.inc.* * * 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) { return $String; } else { $I = 0; while ($I { $StringTMP = substr($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 = "www.at0915.cn"; $Length = "18"; $Append = false; echo sysSubStr($String,$Length,$Append); ?>