Wednesday, March 3, 2010

Codeigniter Crontab Library

Recently i've wrote a library for CodeIgniter framework that handles crontab jobs of the project. This library is very simple, but it's designed to be so.

What does it do

This library sets up cron to perform tasks from crontab file. When crontab file is written with this library. Almost all you need is set up config/crontab.php file.

Installation

  1. Download library from github repository git://github.com/biozshock/crontab.git
  2. If you are familiar with phpunit you can test library. Tests are located in tests subdirectory
  3. Copy config/crontab.php and libraries/crontab.php
  4. Setup config/crontab.php
  5. Use this library

Crontab library config file

cronfile
Path to cronfile library will write all jobs
php_path
Path to PHP executable
crontime
Crontab library default format for date() function
cli_path
PHP cli scripts path
time_offset
This config variable can be used when your server has different timezone from timezone of tasks you want to be cheduled. e.g. server is in -5 timezone. backend in +1 timezone. in backend you setting cronjob for 00:00:00, but for server this would be 14:00:00

Library usage examples

Simple usage

To execute cli script every day at midnight n your controller you should put following code:

$this->load->library('crontab');
$this->crontab->add_job('0 0 * * *', 'cli_script.php');

This code will execute cli_script.php located in directory you've set up in config file at 0 minutes 0 hour

Advanced usage

Assuming you have in your $_POST['time'] time when scheduled action should be performed.

$this->load->library('crontab');
$time = $this->crontab->translate_timestamp(strtotime($this->input->post('time')), 's i G * *');
$this->crontab->add_job($time, 'cli_script.php');


If you want to perform an action every day after user submit a data:

$this->load->library('crontab');
$time = $this->crontab->translate_timestamp(time(), 's i G * *');
$this->crontab->add_job($time, 'cli_script.php');


Warning

Please make sure:
  • your php exec is enabled
  • your server user has access to crontab
  • you know what you are doing
This script will REPLACE ALL crontab jobs for user under which your server is running.