实用技巧：PHP截取中文字符串的问题

<CCID_CODE>function FSubstr($title,$start,$len="",$magic=true) {/**  *  powered by Smartpig  *  mailto:d.einstein@263.net  */  $length = 0;if($len == "") $len = strlen($title);//判断起始为不正确位置if($start > 0){  $cnum = 0;  for($i=0;$i<$start;$i++)  {   if(ord(substr($title,$i,1)) >= 128) $cnum ++;  }  if($cnum%2 != 0) $start--;    unset($cnum);}if(strlen($title)<=$len) return substr($title,$start,$len);$alen   = 0;$blen = 0;$realnum = 0;for($i=$start;$i<STRLEN($TITLE);$I++) if(ord($cur) }else{ } $ctype="0;" ++; $blen { if($magic) $realnum +="4;" $i $length $cstep="0;" i?,substr($title,$i,8),$match)) &#(\d+); if(preg_match(? else $alen ?&#039;?) if(substr($title,$i,6)="=" ?"?) ?&?) if(substr($title,$i,5)="=" ?>?) if(substr($title,$i,4)="=" ?<?) ?&?) if($cur="=" $cur="substr($title,$i,1);">=128)   {    $cstep = 2;    $length += 2;    $i += 1;    $realnum ++;    if($magic)    {     $blen ++;     $ctype = 1;    }   }else{    $cstep = 1;    $length +=1;    $realnum ++;    if($magic)    {     $alen++;    }   }  }    if($magic)  {   if(($blen*2+$alen) == ($len*2)) break;   if(($blen*2+$alen) == ($len*2+1))   {    if($ctype == 1)    {     $length -= $cstep;     break;    }else{     break;    }   }  }else{   if($realnum == $len) break;  }}unset($cur);unset($alen);unset($blen);unset($realnum);unset($ctype);unset($cstep);return substr($title,$start,$length);}</CCID_CODE>