确定字符编码是否为UTF-8格式 函数 (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;
}
}

其中用的的关键函数是 mb_convert_encoding 的解释：

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. [b]mb_convert_encoding() example[/b] /* 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"); ?>