多个PHP中文字符串截取函数

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,3);
$i = $i + 3;
}
elseif( ord($stringTMP) >=192 )
{
$stringTMP = substr($string,2);
$i = $i + 2;
}
else
{
$i = $i + 1;
}
$stringLast[] = $stringTMP;
}
$stringLast = implode("",$stringLast);
if($append)
{
$stringLast .= "...";
}
return $stringLast;
}
} $string = "简明现代魔法 —— 专注于互联网主流的各种技术";
$length = "27";
$append = true;
echo sysSubStr($string,$append);
// 输出
// 简明现代魔法 —— 专...
?>

//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,1)) > 0xa0) {
$tmpstr .= substr($str,2);
$i++;
} else
$tmpstr .= substr($str,1);
}
return $tmpstr;
}
?>

//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);
}
?>

/*
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],$sublen))."...";
return join('',$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,1))>129)
{
$tmpstr.= substr($string,2);
}
else
{
$tmpstr.= substr($string,1);
}
}
if(ord(substr($string,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,'gb2312');
?>