如何更改正在上傳到表單文章的文件名

Question

我有一個以前的表單，該表單將文件上傳到此上傳代碼以及生成的密鑰。我將如何更改文件名POST_ID $，其中文件名當前設置爲profilepicture

<?php 

    session_start(); 

if(!isset($_SESSION["user"]) or !is_array($_SESSION["user"]) or empty($_SESSION["user"])) { 
     // redirect to login page 
} 


$post_id = $_POST['post_id']; 

$target_dir = ('users/'.$_SESSION["user"]["id"].'/feed/'); 
$target_file = $target_dir . 'profilepicture.'.pathinfo($_FILES["fileToUpload"]["name"], PATHINFO_EXTENSION); 
$uploadOk = 1; 
$imageFileType = pathinfo($target_file,PATHINFO_EXTENSION); 
// Check if image file is a actual image or fake image 


// Check if file already exists 

// Check file size 

// 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 header('Location: main.php'); 
    } 
} 
?> 

Answer 1

$target_file = $target_dir . $post_id .'.'.pathinfo($_FILES["fileToUpload"]["name"], PATHINFO_EXTENSION); `