php判断文件编码和检测文件是否有UTF-8头信息

gistfile1.php

<?php

/**
 * 获取内容的编码
 * @param string $str
 */
function get_encoding($str = "") {
	$encodings = array (
		'ASCII', 
		'UTF-8', 
		'GBK' 
	);
	foreach ( $encodings as $encoding ) {
		if ($str === mb_convert_encoding ( mb_convert_encoding ( $str, "UTF-32", $encoding ), $encoding, "UTF-32" )) {
			return $encoding;
		}
	}
	return false;
}

/**
 * 
 * 检测utf-8内容是否含有BOM头信息
 * @param string $str
 */
function utf8_has_bom($str) {
	$chars = substr ( $str, 0, 3 );
	$bom = chr ( 0xEF ) . chr ( 0xBB ) . chr ( 0xBF );
	return $chars === $bom;
}


?>