PHP: upload file-JZTXT

<!DOCTYPE html>
<html>
<body>

<form action="uploadImage.php" method="post" enctype="multipart/form-data">
    Select image to upload:
    <input type="file" name="fileToUpload" id="fileToUpload">
    <input type="submit" value="Upload Image" name="submit">
    <input type="text" value="" id="imagename">
</form>
</body>
</html>

<?php
$target_dir = "uploads/";
$target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]);
$uploadOk = 1;
$imageFileType = strtolower(pathinfo($target_file,PATHINFO_EXTENSION));

// Check if image file is a actual image or fake image
if(isset($_POST["submit"])) {
    $check = getimagesize($_FILES["fileToUpload"]["tmp_name"]);
    if($check !== false) {
        echo "File is an image - " . $check["mime"] . ".";
        $uploadOk = 1;
    } else {
        echo "File is not an image.";
        $uploadOk = 0;
    }
}

// Check if file already exists
if (file_exists($target_file)) {
    echo "Sorry, file already exists.";
    $uploadOk = 0;
}

// Check file size
if ($_FILES["fileToUpload"]["size"] > 500000000000) {
    echo "Sorry, your file is too large.";
    $uploadOk = 0;
}

// Allow certain file formats
if($imageFileType != "jpg" && $imageFileType != "png" && $imageFileType != "jpeg"
    && $imageFileType != "gif" ) {
    echo "Sorry, only JPG, JPEG, PNG & GIF files are allowed.";
    $uploadOk = 0;
}

// Check if $uploadOk is set to 0 by an error
if ($uploadOk == 0) {
    echo "Sorry, your file was not uploaded.";
// if everything is ok, try to upload file
} else {
    if (move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $target_file)) {
        echo "The file ". htmlspecialchars( basename( $_FILES["fileToUpload"]["name"])). " has been uploaded."; //上传成功，和文件名称
    } else {
        echo "Sorry, there was an error uploading your file.";
    }
}
?>

<?php
// 允许上传的图片后缀
$allowedExts = array("gif", "jpeg", "jpg", "png");
$temp = explode(".", $_FILES["fileToUpload"]["name"]);
    echo $_FILES["fileToUpload"]["size"];
    $extension = end($temp);     // 获取文件后缀名
if ((($_FILES["fileToUpload"]["type"] == "image/gif")
|| ($_FILES["fileToUpload"]["type"] == "image/jpeg")
|| ($_FILES["fileToUpload"]["type"] == "image/jpg")
|| ($_FILES["fileToUpload"]["type"] == "image/pjpeg")
|| ($_FILES["fileToUpload"]["type"] == "image/x-png")
|| ($_FILES["fileToUpload"]["type"] == "image/png"))
&& ($_FILES["fileToUpload"]["size"] < 204800000)   // 小于 200 kb
&& in_array($extension, $allowedExts))
{
    if ($_FILES["fileToUpload"]["error"] > 0)
    {
        echo "错误：: " . $_FILES["fileToUpload"]["error"] . "<br>";
    }
    else
    {
        echo "上传文件名: " . $_FILES["fileToUpload"]["name"] . "<br>";
        echo "文件类型: " . $_FILES["fileToUpload"]["type"] . "<br>";
        echo "文件大小: " . ($_FILES["fileToUpload"]["size"] / 1024) . " kB<br>";
        echo "文件临时存储的位置: " . $_FILES["fileToUpload"]["tmp_name"] . "<br>";

        // 判断当前目录下的 upload 目录是否存在该文件
        // 如果没有 upload 目录，你需要创建它，upload 目录权限为
        if (file_exists("uploads/" . $_FILES["fileToUpload"]["name"]))
        {
                echo $_FILES["fileToUpload"]["name"] . " 文件已经存在。 ";
        }
        else
        {
            //$name = $_POST['name'];
            $time = date("Y_m_d")."_".time() ;
            $img = basename($_FILES["fileToUpload"]["name"]);
            $imgfull=$_FILES["fileToUpload"]["name"];
            $targetDir = "uploads/";
            $extensionName=explode('.',$imgfull);
            //echo $extensionName[1];
            //$file_name = $time."_".$img;
            $file_name = $time.".".$extensionName[1];
            $targetFilePath = $targetDir . $file_name;

            move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $targetFilePath);
            echo "rename:".$targetFilePath;
            // 如果 uploads 目录不存在该文件则将文件上传到 uploads 目录下 不改名
            //move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], "uploads/" . $_FILES["fileToUpload"]["name"]);
            // echo "文件存储在: " . "uploads/" . $_FILES["fileToUpload"]["name"];

        }
    }
}
else
{
    echo "非法的文件格式";
}
?>