PHP Recurring Operation

Question

For an iOS Push Notification server, I am implementing a web service that checks a feed on the net for a particular price.

Therefore I need my PHP to keep checking a price (every 20 seconds or so) and check values.

I was wondering (forgive my ignorance I just started with PHP today) is the way people do this a cronjob? Or is there some special way to fire a php script that runs until it's killed and repeats a task?

Thanks! John

the minimum frequency of a cron job is per minute, for 20 seconds i would write a daemon. — , Aug 13 '13 at 20:17
is that really how its done? No simpler way in PHP directly? — Woodstock, Aug 13 '13 at 20:18
its probably done 50 different ways. but for that interval that's how i would do it. perhaps php is not the appropriate language for this. — , Aug 13 '13 at 20:19

score 1 · Answer 1 · edited May 23 '17 at 12:28

1

That is possible by setting up a cron jobs on your server.

Login to your web hosting e.g cpanel create a new cron job and add the path to the php file that you want to run. e.g php /home/[your username]/public_html/rss/import_feeds.php. There is field where you can input the number of minutes would you like the php script to run.

Run a PHP file in a cron job using CPanel

edited May 23 '17 at 12:28

Community

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answered Aug 13 '13 at 20:13

Roseann Solano

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score 1 · Accepted Answer · answered Aug 13 '13 at 20:52

If PHP was your preferred route, a simple script such as the following can be set to run indefinitely in the background (name this grabber.php):

#!/usr/bin/php
<?php
do {
    // Grab the data from your URL
    $data = file_get_contents("http://www.example.com/data.source");

    // Write the data out somewhere so your push notifications script can read it
    file_put_contents("/path/to/shared/data.store", $data);

    // Wait and do it all over again
    sleep(20);
} while (true);

And to start it (assuming you're on a unixy OS):

$ chmod u+x grabber.php
$ ./grabber.php > /path/to/a/file/logging/script/output.log 2>&1 &

That & at the end sends the process to run in the background.

PHP is probably overkill for this however, perhaps a simple bash script would be better:

#!/bin/bash
# This downloads data and writes to a file ('data-file')
doWork () {
    data=$(curl -L http://www.example.com/data.source)
    echo $data > data-file
    sleep 20
    doWork
}

# Start working
doWork

$ chmod u+x grabber.sh
$ ./grabber.sh > /path/to/logger.log 2>&1 &

great stuff! thanks! I need PHP to set up a secure connection to the apple push notification server and send a json string. sockets etc... can't use bash. — Woodstock, Aug 13 '13 at 20:58

PHP Recurring Operation

2 Answers2