php文件上传源代码

<?php
if(isset($_POST[\'submit\'])){
    $file_name = $_FILES[\'file\'][\'name\'];
    $file_size = $_FILES[\'file\'][\'size\'];
    $file_tmp = $_FILES[\'file\'][\'tmp_name\'];
    $file_type = $_FILES[\'file\'][\'type\'];
    $file_ext = strtolower(end(explode(\'.\', $_FILES[\'file\'][\'name\'])));
    
    $extensions = array(jpeg,jpg,png);
    
    if(in_array($file_ext, $extensions) === false){
        echo Extension not allowed, please choose a JPEG or PNG file.;
    }
    
    if($file_size > 2097152){
        echo \'File size must be less than 2 MB\';
    }
    
    $upload_path = uploads/.$file_name;
    move_uploaded_file($file_tmp, $upload_path);
    echo Success;
}
?>