Creating and Installing crontabs using CodeIgniter

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Last night, I was trying to get a crontab working in CodeIgniter, since my current project (a personal project) is using CodeIgniter now. I didn’t wanted to use the conventional approach of running crontabs and my code seperate.

Unfortunately, CodeIgniter does not have support for Crontabs and I didn’t wanted to user wget in linux crontab to initiate unwanted requests.

I spent some time and came up with a solution. It uses

  1. CodeIgniter backend
  2. Does not modify any core architecture of CodeIgniter
  3. Keeps configuration at one place

So enough of the summary and let me show you how its done.
Create a file (e.g. cron.php) in the same place as your index.php and system folder. Here is its code

/**
* @author 	    Asim Zeeshan
* @web         http://www.asim.pk/
* @date		13th May, 2009
* @copyright 	No Copyrights, but please link back in any way
*/

/*
|---------------------------------------------------------------
| CASTING argc AND argv INTO LOCAL VARIABLES
|---------------------------------------------------------------
|
*/
$argc = $_SERVER['argc'];
$argv = $_SERVER['argv'];

// INTERPRETTING INPUT
if ($argc > 1 && isset($argv[1])) {
$_SERVER['PATH_INFO'] 	= $argv[1];
$_SERVER['REQUEST_URI'] = $argv[1];
} else {
$_SERVER['PATH_INFO'] 	= '/crons/index';
$_SERVER['REQUEST_URI'] = '/crons/index';
}

/*
|---------------------------------------------------------------
| PHP SCRIPT EXECUTION TIME ('0' means Unlimited)
|---------------------------------------------------------------
|
*/
set_time_limit(0);

require_once('index.php');

/* End of file test.php */

Now, we need a controller e.g. test so the controller code could be something like this. Please note that normally we do not need to output anything from these controllers since they are doing some background work or sending emails but for the sake of giving an example, I will be output-ing something to elaborate the example.

/**
* @author 	    Asim Zeeshan
* @web         http://www.asim.pk/
* @date		13th May, 2009
* @copyright 	No Copyrights, but please link back in any way
*/</code>

class Test extends Controller {

function __construct()
{
parent::Controller();
}

function index()
{
echo "testing from index \n";
}

function test() {
echo "testing from test \n";
}
}

Now execute crontab on linux command prompt

php /full-path-to-cron-file/cron.php /test/index

Voila! all you need now, is to setup the crontab like you normally do.
This code is not shared under any license so feel free to copy/modify/use it. Please link back to this website / post in any way e.g. direct link, credits etc.

P.S. The examples above user PHP5 constructor, If you need to execute this code on PHP4, please modify the constructors.

21 Comments

    • Yes, thats an easy way but why do we need to initiate wget and an unnecessary http request when we can do it from within the system? Thats why I came up with this tutorial.

  • Amir Bilal

    "invoking wget by cron is a real “unix way”.

    No It was never…

    Of course, it is easy to have them under the HTTP path but most of the times I have realized that making them secure is more necessary. At times if you have not performed proper checks then unwanted access to the cron URLs can get you in trouble.

    Just as a side note: CodeIgniter wiki has an article about setting up cron jobs in CI. I used that somewhere in 2007.

    Best regards,

  • Nathan

    I really like the way this would work but for some reason I am getting no output once the Core Codeigniter Class is loaded. My script seems to run but gives me no output or errors. I do get output if i echo something before:

    require_once BASEPATH.'codeigniter/CodeIgniter'.EXT;

    but nothing after that.

    Any ideas?

    Thank you

  • prabha

    Nice post. i tried in many ways. this works fine now.

    I am using cron to send mail . i am getting the mail . But an extra mail is coming with the following error

    PHP Notice: Undefined index: HTTP_HOST in httpdocs/index.php on line 131
    PHP Notice: Undefined variable: region_prefix_var in httpdocs/index.php on line 135
    PHP Notice: Undefined index: HTTP_HOST in httpdocs/application/config/config.php on line 23

    A PHP Error was encountered

    Severity: Notice
    Message: Undefined index: HTTP_HOST
    Filename: config/config.php
    Line Number: 23

    A PHP Error was encountered

    Severity: Notice
    Message: Undefined index: HTTP_HOST
    Filename: config/config.php
    Line Number: 23

    A PHP Error was encountered

    Severity: Warning
    Message: Cannot modify header information – headers already sent by (output started at httpdocs/system/core/Exceptions.php:185)
    Filename: libraries/Session.php
    Line Number: 672

    A PHP Error was encountered

    Severity: Notice
    Message: Undefined index: HTTP_HOST
    Filename: hooks/subdomain_check.php
    Line Number: 15

    A PHP Error was encountered

    Severity: Warning
    Message: Cannot modify header information – headers already sent by (output started at httpdocs/system/core/Exceptions.php:185)
    Filename: hooks/subdomain_check.php
    Line Number: 45

    A PHP Error was encountered

    Severity: Warning
    Message: Cannot modify header information – headers already sent by (output started at httpdocs/system/core/Exceptions.php:185)
    Filename: libraries/Session.php
    Line Number: 672

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