url 取出文件扩展名

/*
*url 取出文件扩展名
 */
//方法一
function getExt1($url) {
    $arr = parse_url($url);
    $file = basename($arr[‘path‘]);
    $ext = explode(‘.‘, $file);
    return $ext[count($ext)-1];
}
$path = ‘http://www.sina.com.cn/abc/de/fg.php?id=1‘;
echo getExt1($path);//php
echo ‘<br/>‘;
//方法二
function getExt2($url) {
    $url = basename($url);
    $post1 = strpos($url,‘.‘);
    $post2 = strpos($url,‘?‘);
    if(strstr($url,‘?‘)) {
        return substr($url, $post1+1,$post2-$post1-1);
    } else {
        return substr($url, $post1);
    }
    
}
echo getExt2($path);//php
echo ‘<br/>‘;

//方法三
function getExt3($file) {
    return pathinfo($file,PATHINFO_EXTENSION);
}
echo getExt3($path);//php?id=1
echo ‘<br/>‘;

//方法四
$info = explode(‘.‘, $path);
echo end($info);
echo "<br/>";