Php UTF文件编码识别

最新推荐文章于 2021-04-13 05:50:33 发布

最新推荐文章于 2021-04-13 05:50:33 发布 · 149 阅读

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#PHP

本文介绍了一种PHP脚本方法，用于检测文件的UTF编码格式，包括UTF-8、UTF-16BE、UTF-16LE、UTF-32BE和UTF-32LE。通过读取文件开头的字节来判断其BOM（字节顺序标记），从而确定文件的编码类型。

用于判断文件是否使用UTF编码

<?php
// Unicode BOM is U+FEFF, but after encoded, it will look like this.
define ('UTF32_BIG_ENDIAN_BOM' , chr(0x00) . chr(0x00) . chr(0xFE) . chr(0xFF));
define ('UTF32_LITTLE_ENDIAN_BOM', chr(0xFF) . chr(0xFE) . chr(0x00) . chr(0x00));
define ('UTF16_BIG_ENDIAN_BOM' , chr(0xFE) . chr(0xFF));
define ('UTF16_LITTLE_ENDIAN_BOM', chr(0xFF) . chr(0xFE));
define ('UTF8_BOM' , chr(0xEF) . chr(0xBB) . chr(0xBF));

/**
*@return 返回UTF编码格式
*
*/
function detect_utf_encoding($filename) {

$text = file_get_contents($filename);
$first2 = substr($text, 0, 2);
$first3 = substr($text, 0, 3);
$first4 = substr($text, 0, 3);

if ($first3 == UTF8_BOM) return 'UTF-8';
elseif ($first4 == UTF32_BIG_ENDIAN_BOM) return 'UTF-32BE';
elseif ($first4 == UTF32_LITTLE_ENDIAN_BOM) return 'UTF-32LE';
elseif ($first2 == UTF16_BIG_ENDIAN_BOM) return 'UTF-16BE';
elseif ($first2 == UTF16_LITTLE_ENDIAN_BOM) return 'UTF-16LE';
}

?>