Coding with Jesse

Saving data to a file with PHP

February 24th, 2008

Lately, I've been skipping using MySQL in situations where I just want to store a few variables, like configuration options, and don't necessarily want the hassle of setting up a database.

You can easily store data to a file using serialize and unserialize to turn a PHP object into a string, and then read and write the string in a file.

Here are a few functions that do just that:

function get_data($filename) {
    // create file if it doesn't exist
    if (!file_exists($filename)) {

    return unserialize(file_get_contents($filename));

function get_option($filename, $key) {
    $data = get_data($filename);
    return $data[$key];

function set_option($filename, $key, $value) {
    $data = get_data($filename);
    $data[$key] = $value;

    // write to disk
    $fp = fopen($filename, 'w');
    fwrite($fp, serialize($data));

// probably should put somewhere off the web root
$config = '../config.dat';

set_option($config, 'width', 1024);
echo get_option($config, 'width'); // will echo 1024

So there you have it. Feel free to use or modify this code as much as you like. If anyone has an idea for rewriting it to be cleaner, please share in the comments.

About the author

Jesse Skinner Hi, I'm Jesse Skinner. I'm a self-employed web developer with over two decades of experience. I love learning new things, finding ways to improve, and sharing what I've learned with others. I love to hear from my readers, so please get in touch!