I've got a PHP script that simply e-mails me a test message. If I go into my webserver cPanel I can create a cronjob that runs the script every 10 minutes and it works perfectly.
I manually schedule the cron job in cPanel using the following settings:
10 * * * * php -q /home1/user1/public_html/mail.php
Again the above works fine, but when I try to create the cron job via PHP instead of cPanel it never runs. When I check the cPanel to see if the job was actually created by my php script it DOES show up. All the settings that show up in cPanel are correct, it just doesn't run the script.
This is the PHP code I'm using to create the cron job:
$output = shell_exec('crontab -l');
file_put_contents('/tmp/crontab.txt', $output.'10 * * * * php -q /home1/user1/public_html/mail.php'.PHP_EOL);
echo exec('crontab /tmp/crontab.txt');
I imagine it could be a permission issue or something like that? Not really sure why the job works when I create it, but doesn't when PHP creates it.