上传后如何更改文件名 PHP

How to change file name after upload PHP

目前,我的代码使用用户提交的图片名称上传一个图片文件。现在显然我想改变它以避免覆盖问题。现在,我已经查看了其他一些建议,但我似乎无法让它与我的代码一起工作(我只学习 PHP 几个月)。那么,你们能帮帮我吗?这是上传代码

<?php
$target_dir = "avatars/";
$target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]);
$uploadOk = 1;
$imageFileType = pathinfo($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"] > 500000) {
    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 ". basename( $_FILES["fileToUpload"]["name"]). " has been uploaded.";
    } else {
        echo "Sorry, there was an error uploading your file.";
    }
}
?>

我的猜测是我需要更改 move_uploaded_file 代码?感谢您的帮助!

改变这个:

$target_dir = "avatars/";
$target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]);

为此:

$rand = rand(10000000, 999999999);
$time = time();
$file_name = $rand.$time.$_FILES["fileToUpload"]["name"];
$target_dir = "avatars/";
$target_file = $target_dir . $file_name;

移动前重命名文件。(如果它退出)

// Check if file already exists
 if (file_exists($target_file)) {
    $temp = explode(".", $_FILES["fileToUpload"]["name"]); //getting the image extension
    $target_file = $target_dir . rand(1,99999).'.'.end($temp);
   $uploadOk = 0;
 }