php - Storing $_POST values in an array to save them to text file

Question

I have multiple $_POST values which I want to store in an array to save to a text file. How would I go about doing this?

PHP code:

<?php

$name=$_POST["name"] 
$email=$_POST["email"] 
$msg=$_POST["msg"] 
$origin=$_POST["origin"] 

$file="test.txt"; 
$open=fopen($file,"a"); 

if($open){         
    fwrite($open, $entry); 
        fclose($open); 
}

?>

$entry is supposed to be the array

Answer 1

$data["name"]=$_POST["name"] 
$data["email"]=$_POST["email"] 
$data["msg"]=$_POST["msg"] 
$data["origin"]=$_POST["origin"] 

file_put_contents("filename.txt", serialize($data));

and to bring those values back from a file:

$data = unserialize(file_get_contents("filename.txt"));