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:

  <?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

  

复制代码 代码如下:

  <?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

  

复制代码 代码如下:

  <?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

  

复制代码 代码如下:

  <?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 <[email][email protected][/email]>

  * @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 = "www.at0915.cn";

  $Length = "18";

  $Append = false;

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

  ?>