Reading and writing global variables across scripts in PHP

Question

Does PHP have global variables that can be modified by one running script and read by another?

Answer 1

I made a tiny library (~2 KB; <100 lines) that allows you to do just this: varDx

It has functions to write, read, modify, check and delete data. It implements serialization, and therefore supports all data types.

Here's how you can use it:

<?php
require 'varDx.php';
$dx = new \varDx\cDX; //create an object
$dx->def('file.dat'); //define data file

$val1 = "this is a string";
$dx->write('data1', $val1); //writes key to file
echo $dx->read('data1'); //returns key value from file

Answer 2

You can use $_SESSION, i.e.:

script1.php

<?php
session_start();
$_SESSION['myVar'] = "something";
?>

script2.php

<?php
session_start();
echo $_SESSION['myVar'];
//something
?>

Answer 3

Another common substitution for global variables in PHP is the shared use of a database like MySQL (albeit not a perfect one)