Why?

A lot of my web projects require import scripts and other actions that maintain the website outside the typical http request. Most of the time, I use the CLI requests in “cron jobs”, or scripts that are automatically called at certain times by the server operating system. CodeIgniter doesn’t have this CLI (command line) functionality, so we have to add it in ourselves.

Existing/Old Method

In order to call a controller/method from the command line, a separate file needs to be created that manually sets the REQUEST_URI / PATH_INFO, which are both Apache environment variables and are used by CI to determine which controller & method to call up. We need to set those items as well as a couple others to make this possible. Time for an example:

#!/usr/bin/php
<?php
/* make sure this isn't called from a web browser */
if (isset($_SERVER['REMOTE_ADDR'])) die('Permission denied.');

/* set the controller/method path */
$_SERVER['PATH_INFO'] = $_SERVER['REQUEST_URI'] = '/cron/purge_cache';

/* raise or eliminate limits we would otherwise put on http requests */
set_time_limit(0);
ini_set('memory_limit', '256M');

/* call up the framework */
include(dirname(__FILE__).'/index.php');
?>

Since this is a shell script, we need the hashbang (line 1 of the example). This tells Bash what binary to use to run the script. If /usr/bin/php is not the path to PHP in your environment, you will need to change that accordingly.

Line 4 simply detects whether it is being ran through a shell session or browser. If we have a remote IP address, then it was accessed by a web browser.

Line 7 is the import one. This sets the controller/method to call. In my example, we are calling the ‘cron’ controller and the ‘purge_cache’ method.

There is one big problem with this method. We have to create a file for every possible command line request. As you can see, the requested controller/method is hard-coded in the file. This method works ok when we only have one or two things callable by the command line, but usually, I have more than that.

My New Method

PHP has the option to accept command-line arguments, and we are going to use that to our advantage. For my solution, I created a copy of index.php, and saved it as cli.php. I then added the following code to the top of the file:

#!/usr/local/bin/php
<?php

/**
 * only a few lines of code will make the best web framework
 * function on the command line
 */

	/* we don't need to be limited by...normal limitations */
	set_time_limit(0);
	ini_set('memory_limit', '256M');

	/* make sure this isn't being called by a web browser */
	if (isset($_SERVER['REMOTE_ADDR'])) die('Permission denied.');

	/* set some constants */
	define('CMD', 1);

	/* manually set the URI path based on command line arguments... */
	unset($argv[0]); /* ...but not the first one */
	$_SERVER['PATH_INFO'] = $_SERVER['REQUEST_URI'] = '/' . implode('/', $argv) . '/';

Lines 10-14 should look familiar, as I took that form the previous example. Line 17 is just a constant that we will use later.

I am using PHP’s $argv variable to get a list of the arguments, so if I called the script by saying:

./cli.php cron purge_cache

…then $argv would be an array with the elements of ‘cli.php’, ‘cron’, ‘purge_cache’. I don’t need the first element, so I unset that in line 20. Then I implode the rest of the elements to form the request path, and the end result would be /cron/purge_cache/, just like our hard-coded example at the beginning.

By doing it this way, we created another handler that can run any controller on the command line w/o modifications. The only thing we needed was a handler for CLI requests.

A Step Further – Custom Error Pages

CodeIgniter’s error pages have HTML that we don’t need to see in our command line. I defined that CMD constant so I can tell if we are accessing via the CLI or web browser. The following bit of code is my 404 error page found at ./system/application/errors/error_404.php. I use some conditionals and show a plain-text form of the error if viewed in the CLI.

<?php header("HTTP/1.1 404 Not Found"); ?>
<?php if(defined('CMD')) : ?>

***<?php echo $heading; ?>***

<?php echo $message; ?>

<?php else : ?>
<html>
<head>
<title>404 Page Not Found</title>
<style type="text/css">

body {
background-color:	#fff;
margin:				40px;
font-family:		Lucida Grande, Verdana, Sans-serif;
font-size:			12px;
color:				#000;
}

#content  {
border:				#999 1px solid;
background-color:	#fff;
padding:			20px 20px 12px 20px;
}

h1 {
font-weight:		normal;
font-size:			14px;
color:				#990000;
margin: 			0 0 4px 0;
}
</style>
</head>
<body>
	<div id="content">
		<h1><?php echo $heading; ?></h1>
		<?php echo $message; ?>
	</div>
</body>
</html>
<?php endif; ?>

So there you have it, following these steps will turn one of the best PHP frameworks into a CLI-capable wonder. Please feel free to post a comment if you have a question or anything to add.

For more information on using PHP from the command line, see http://us.php.net/features.commandline.

• Loading INI Files in PHP