php - How to schedule notification

Question

So I have a database that I query from to check if the date on there is equals to today's date. Is there a way I can run this PHP script without visiting this page to check if there is any date that is equals to the todays date and send FCM notification? Below is example of what am looking at:

<?php
$todaydate = date("Y-m-d");

$query = "select * from TABLE where date = $todaydate";
$result = mysqli_query($db, $query);
if(mysqli_num_rows($result) > 0){

...sending FCM notification      

}

?>

I know cronjob can do this but don't know how to use on to achieve this.

question from:https://stackoverflow.com/questions/66054660/how-to-schedule-notification

Answer 1

You can just run the script (for example) every 12 hours.

You can either do this with the Linux command crontab -e for the currently logged-in user or you can edit /etc/crontab to run the script as a specific user.

With crontab -e your line would look like this:

0 */12 * * * php /path/to/script.php >/dev/null 2>&1

As I said, in /etc/crontab you can specify a specific user. It would look like this:

0 */12 * * * username php /path/to/script.php >/dev/null 2>&1

username can be something like www-data. Just make sure the specified user has read/execute permissions on the script's file.

>/dev/null 2>&1 means that the output of the command is muted. You could also write the output into a file. There are also crontab-generators.