php识别中文编码并自动转换为UTF-8

function characet($data){
  if( !empty($data) ){
    $fileType = mb_detect_encoding()($data , array('UTF-8','GBK','LATIN1','BIG5')) ;
    if( $fileType != 'UTF-8'){
      $data = mb_convert_encoding($data ,'utf-8' , $fileType);
    }
  }
  return $data;
}
?>

$temstr=file_get_contents($path);
$encode   = mb_detect_encoding($temstr,"ASCII,UTF-8,CP936,EUC-CN,BIG-5,EUC-TW");   
$temstr=mb_convert_encoding($temstr,   "CP936",   $encode); 

$f=fopen("test.txt", "wb");  
$text=utf8_encode("a!");  
 
//先用函数utf8_encode将所需写入的数据变成UTF编码格式。  
 
$text="＼＼xEF＼＼xBB＼＼xBF".$text;  
 
//"＼＼xEF＼＼xBB＼＼xBF",这串字符不可缺少，生成的文件将成为UTF-8格式，否则依然是ANSI格式。  
 
fputs($f, $text);  
 
//写入。  
 
fclose($f);  
?>