How to save php config? - php

Question

I have a standard config file: $variable = 'value';, but at the last moment came up to use the web interface to configure it. So what is the best way to read the file, find the value of variables and then resave the file again?
At the moment I have 2 ideas:
1) RegExp
2) Keep somewhere array example

Answer 1

Store all config values in an associative array like so:
$config = array(
'variable' => 'value'
);
For the web interface, you can easily loop over the entire array:
foreach($config as $key=>$value) { ... }
After making changes, loop over the array and write it back to the file. (You really should be using a DB for this, though).
When you include the file, you can either use it like this:
include('config.php');
echo $config['variable']
// or
extract($config);
echo $variable;
Note: If you extract, it will overwrite any variables by the same name you might have defined before extracting.
PS - To make it easier to read and write to and from a file, I would just use json encoding to serialize the array.

Answer 2

Use a db
If your config is user defined - it would be better to store the config in a database. Otherwise you have this "novel" problem to solve but also potentially introduce security problems. I.e. for any one user to be able to edit your config files - they must be writeable to the webserver user. That opens the door to injecting malicious code into this file from a web exploit - or simply someone with direct access to your server (shared host?) finding this writeable file and updating it to their liking (e.g. putting "<?php header('Location: my site'); die;" in it).
One config variable
If you must manage it with a config file, include the file to read it, and var_export the variables to write it. That's easiest to do if there is only one config variable, that is an array. e.g.:
function writeConfig($config = array()) {
$arrayAsString = var_export($config, true);
$string = "<?php\n";
$string .= "\$config = $arrayAsString;\n";
file_put_contents('config.php', $string);
}
Allow partial updates
If you are changing only some variables - just include the config file before rewriting it:
function writeConfig($edits = array()) {
require 'config.php';
$edits += $config;
$arrayAsString = var_export($edits, true);
$string = "<?php\n";
$string .= "\$config = $arrayAsString;\n";
file_put_contents('config.php', $string);
}
Multiple config variables
If you have more than one variable in your config file, make use of get defined vars and loop on them to write the file back:
function writeConfig($_name = '', $_value) {
require 'config.php';
$$_name = $_value; // This is a variable variable
unset($_name, $_value);
$string = "<?php\n";
foreach(get_defined_vars() as $name => $value) {
$valueAsString = var_export($value, true);
$string .= "\$$name = $valueAsString;\n";
file_put_contents('config.php', $string);
}
}
The above code makes use of variable variables, to overwrite once of the variables in the config file. Each of these last two examples can easily be adapted to update multiple variables at the same time.