phpcms图片上传功能

<?php
if ($_FILES['image']['error'] == UPLOAD_ERR_OK) {
    $fileTmpPath = $_FILES['image']['tmp_name'];
    $fileName = $_FILES['image']['name'];
    $fileSize = $_FILES['image']['size'];
    $fileType = $_FILES['image']['type'];
    $fileNameCmps = explode(".", $fileName);
    $fileExtension = strtolower(end($fileNameCmps));

    $allowedFileExtensions = array('jpg', 'jpeg', 'png', 'gif');

    if (in_array($fileExtension, $allowedFileExtensions)) {
        if ($fileSize < 2000000) { // 2MB
            $newFileName = md5(date('YmdHis') . "_" . $fileName) . '.' . $fileExtension;
            $dest_path = 'uploads/' . $newFileName;

            if (move_uploaded_file($fileTmpPath, $dest_path)) {
                echo "File is successfully uploaded.";
            } else {
                echo "Upload failed. Please make sure the 'uploads' folder exists and is writable.";
            }
        } else {
            echo "File size exceeds 2MB.";
        }
    } else {
        echo "Invalid file extension. Allowed extensions are: jpg, jpeg, png, gif.";
    }
} else {
    echo "Error uploading file.";
}
?>