<?php

header("Content-type: text/html; charset=utf-8");

/**

 * 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;

}

// $filename = 'C:\Users\Administrator\Desktop\test.txt';

// $filename = 'C:\Users\Administrator\Desktop\ansi.txt';

// $filename = 'C:\Users\Administrator\Desktop\Unicode.txt';

$filename = 'C:\Users\Administrator\Desktop\my.txt';

// 检测编码

$str = file_get_contents($filename);

$encode = get_encoding($str);

var_dump($encode);

// 转换成"UTF-8"编码

if($encode != 'UTF-8'){

    $str = mb_convert_encoding($str, "UTF-8", $encode);

}

var_dump($str);