Use PHP to create, edit and delete crontab jobs?

Question

Is it possible to use PHP to create, edit and delete crontab jobs?

I know how to list the current crontab jobs of the Apache user:

$output = shell_ex         


        

Answer 1

Nice...
Try this to remove an specific cron job (tested).

<?php $output = shell_exec('crontab -l'); ?>
<?php $cron_file = "/tmp/crontab.txt"; ?>

<!-- Execute script when form is submitted -->
<?php if(isset($_POST['add_cron'])) { ?>

<!-- Add new cron job -->
<?php if(!empty($_POST['add_cron'])) { ?>
<?php file_put_contents($cron_file, $output.$_POST['add_cron'].PHP_EOL); ?>
<?php } ?>

<!-- Remove cron job -->
<?php if(!empty($_POST['remove_cron'])) { ?>
<?php $remove_cron = str_replace($_POST['remove_cron']."\n", "", $output); ?>
<?php file_put_contents($cron_file, $remove_cron.PHP_EOL); ?>
<?php } ?>

<!-- Remove all cron jobs -->
<?php if(isset($_POST['remove_all_cron'])) { ?>
<?php echo exec("crontab -r"); ?>
<?php } else { ?>
<?php echo exec("crontab $cron_file"); ?>
<?php } ?>

<!-- Reload page to get updated cron jobs -->
<?php $uri = $_SERVER['REQUEST_URI']; ?>
<?php header("Location: $uri"); ?>
<?php exit; ?>
<?php } ?>

<b>Current Cron Jobs:</b><br>
<?php echo nl2br($output); ?>

<h2>Add or Remove Cron Job</h2>
<form method="post" action="<?php $_SERVER['REQUEST_URI']; ?>">
<b>Add New Cron Job:</b><br>
<input type="text" name="add_cron" size="100" placeholder="e.g.: * * * * * /usr/local/bin/php -q /home/username/public_html/my_cron.php"><br>
<b>Remove Cron Job:</b><br>
<input type="text" name="remove_cron" size="100" placeholder="e.g.: * * * * * /usr/local/bin/php -q /home/username/public_html/my_cron.php"><br>
<input type="checkbox" name="remove_all_cron" value="1"> Remove all cron jobs?<br>
<input type="submit"><br>
</form>

Answer 2

Depends where you store your crontab:

shell_exec('echo "'. $job .'" >> crontab');

Answer 3

The easiest way is to use the shell_exec command to execute a bash script, passing in the values as parameters. From there, you can manipulate crontabs like you would in any other non-interactive script, and also ensure that you have the correct permissions by using sudo etc.

See this, Crontab without crontab -e, for more info.

Answer 4

We recently prepared a mini project (PHP>=5.3) to manage the cron files for private and individual tasks. This tool connects and manages the cron files so you can use them, for example per project. Unit Tests available :-)

Sample from command line:

bin/cronman --enable /var/www/myproject/.cronfile --user www-data

Sample from API:

use php\manager\crontab\CrontabManager;

$crontab = new CrontabManager();
$crontab->enableOrUpdate('/tmp/my/crontab.txt');
$crontab->save();

Managing individual tasks from API:

use php\manager\crontab\CrontabManager;

$crontab = new CrontabManager();
$job = $crontab->newJob();
$job->on('* * * * *');
$job->onMinute('20-30')->doJob("echo foo");
$crontab->add($job);
$job->onMinute('35-40')->doJob("echo bar");
$crontab->add($job);
$crontab->save();

github: php-crontab-manager

Answer 5

You can put your file to /etc/cron.d/ in cron format. Add some unique prefix to the filenaname To list script-specific cron jobs simply work with a list of files with a unique prefix. Delete the file when you want to disable the job.

Answer 6

Its simple You can you curl to do so, make sure curl installed on server :

for triggering every minute : * * * * * curl --request POST 'https://glassdoor.com/admin/sendBdayNotification'

• • • • *

  minute hour day month week

Let say you want to send this notification 2:15 PM everyday You may change POST/GET based on your API:

15 14 * * * curl --request POST 'url of ur API'