確定字符編碼是否爲UTF-8格式 函數 (1)

function phpdigVerifyUTF8($str) {
  // verify if a given string is encoded in valid utf-8
  if ($str === mb_convert_encoding(mb_convert_encoding($str, "UTF-32", "UTF-8"), "UTF-8", "UTF-32")) {
    return $str;
  }
  else {
    return false;
  }
}

 其中用的的關鍵函數是 mb_convert_encoding 的解釋：

 

mb_convert_encoding

(PHP 4 >= 4.0.6, PHP 5)

mb_convert_encoding -- Convert character encoding

Description

string mb_convert_encoding ( string str, string to_encoding [, mixed from_encoding] )

mb_convert_encoding() converts character encoding of string str from from_encoding to to_encoding.

str : String to be converted.

from_encoding is specified by character code name before conversion. it can be array or string - comma separated enumerated list. If it is not specified, the internal encoding will be used.

例子 1. mb_convert_encoding() example

/* Convert internal character encoding to SJIS */
$str = mb_convert_encoding($str, "SJIS");

/* Convert EUC-JP to UTF-7 */
$str = mb_convert_encoding($str, "UTF-7", "EUC-JP");

/* Auto detect encoding from JIS, eucjp-win, sjis-win, then convert str to UCS-2LE */
$str = mb_convert_encoding($str, "UCS-2LE", "JIS, eucjp-win, sjis-win");

/* "auto" is expanded to "ASCII,JIS,UTF-8,EUC-JP,SJIS" */
$str = mb_convert_encoding($str, "EUC-JP", "auto");
?>