PHP：检查字符串是 utf-8 还是 utf-16le-解网

问：

我正在编写默认以 utf-8 格式返回文档的函数，如果您提供特殊参数，它将返回 utf-16le 中的内容。我开始为这个函数编写单元测试，我不明白的是如何检查编码是“utf-8”还是“utf-16le”。我已经尝试过了，但它甚至在这个代码片段中返回：mb_detect_encodingfalse

  $utf16Doc = mb_convert_encoding($doc, "utf-16le", "utf8");
  $test = mb_detect_encoding($utf16Doc, "utf-16le");
  var_dump($test);

欣赏任何想法，如何检查编码是 utf-16le 而不是 utf-8。

php utf-16le mb-convert-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));

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';
}
?>

所以现在你可以这样尝试，

 $utf16Doc = mb_convert_encoding($doc, "utf-16le", "utf8");
 $test = detect_utf_encoding($utf16Doc);
 var_dump($test);

明确说明：这不是我自己的书面答复。我刚刚在 php.net 官方网站上找到了它，用户 http://php.net/manual/en/function.mb-detect-encoding.php#68607。希望这会以某种方式对您有所帮助mb_detect_encoding

PHP：检查字符串是 utf-8 还是 utf-16le

PHP: checking if string is utf-8 or utf-16le

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