Complete collection of PHP string interception methods Four examples of PHP string interception

//Intercept Chinese string
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. Intercept utf8 encoded multi-byte string

//Intercept utf8 string
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, and GB2312 support Chinese character interception function

/*
 The Chinese character interception function cut_str (string, interception length, starting length, encoding) supported by Utf-8 and gb2312; the default encoding is utf-8 and the default starting length is 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; } } $str = "abcd string to be intercepted"; echo cut_str($str, 8, 0, 'gb2312'); ?>

4. BugFree’s character interception function

/**
 * @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 -- Simple, wonderful, versatile";
$Length = "18";
$Append = false;
echo sysSubStr($String,$Length,$Append);
?>