Cron Job not refreshing page every 5 seconds

Question

I'm trying to have my page refresh ever 5 seconds to update data. Though Cron only runs every 1 minute. So I tried to incorporate into the page I'm loading a self refresh every 5 seconds.

My Cron job is: /usr/bin/php /home/cplpc/public_html/commons/btc-fetch.php

This seems to update my code, though only once every minute.

The btc-fetch.php page I've created is:

<?php
    $page = $_SERVER['PHP_SELF'];
    $sec = "5";
 ?>
<html>
<head>
<meta http-equiv="refresh" content="<?php echo $sec?>;URL='<?php echo $page?>'">
<meta name="robots" content="noindex">
<meta name="googlebot" content="noindex">
</head>
<body>
<?php
    $url = "https://www.bitstamp.net/api/ticker";
    $fgc = file_get_contents($url);
    file_put_contents('/home/cplpc/public_html/data/btc-the-price', $fgc);
    echo $fgc;
?>
</body>

Any guidance or direction would be greatly appreciated. This script works if I have btc-fetch.php open in my browser, though I assume this is because 'it's in a browser'? Is there anyway to achieve the same desired task?

* Thanks for the replies

I'm using cPanel for the Cron Job. Perhaps I need to look at another way then PHP_SELF refresh. Thanks for the tips.

um.... what you posted is meant to run off the web and a web browser, not cron. — Funk Forty Niner, Apr 11 '18 at 12:44
Solution: Modify your cron to run every 5 seconds. Would you like this as an answer? Edit: or whatever minimum time cron lets you. — Funk Forty Niner, Apr 11 '18 at 12:48
@FunkFortyNiner conjobs can only run every minute. that's the smallest interval. — Binar Web, Apr 11 '18 at 12:49
You should re-read what Cron Jobs are and how the work. @FunkFortyNiner, I don't think you can have they interval lower than 60 seconds? https://askubuntu.com/questions/800/how-to-run-scripts-every-5-seconds?utm_medium=organic&utm_source=google_rich_qa&utm_campaign=google_rich_qa — Adam, Apr 11 '18 at 12:49
check your URL render accurate formate exmaple: content="0;URL=http://www.example.com" — Shahbaz Zafar, Apr 11 '18 at 12:49
Chrono appears to be *a C++11 library for representing and manipulating time*. I presume you mean **cron**. And your approach won't work unless you have the time and GBs of RAM required to schedule a full-fledged web browser. — Álvaro González, Apr 11 '18 at 12:50
@BinarWeb yeah; I was going to add "or whatever minimum time cron lets you" ;-) edited — Funk Forty Niner, Apr 11 '18 at 12:50
@ShahbazZafar even still; meta tags don't do anything in cron. — Funk Forty Niner, Apr 11 '18 at 12:52
@FunkFortyNiner what actually you are guiding him to handle cron from Cpanel, which help him more its quiet make sen's but might he don't have access to the panel if he have then he have to follow you. — Shahbaz Zafar, Apr 11 '18 at 12:54
Thanks all, I'll have to re-think and approach my refresh to be a time interval or something. At least your comments have helped me. :-) — aussiedan, Apr 11 '18 at 13:04

score 1 · Accepted Answer · answered Apr 11 '18 at 12:55

You can do it with cronjobs, but it's probbaly not a very good approach.

* * * * * /usr/bin/php /home/cplpc/public_html/commons/btc-fetch.php
* * * * * sleep 5 && /usr/bin/php /home/cplpc/public_html/commons/btc-fetch.php
* * * * * sleep 10 && /usr/bin/php /home/cplpc/public_html/commons/btc-fetch.php
* * * * * sleep 15 && /usr/bin/php /home/cplpc/public_html/commons/btc-fetch.php
* * * * * sleep 20 && /usr/bin/php /home/cplpc/public_html/commons/btc-fetch.php
* * * * * sleep 30 && /usr/bin/php /home/cplpc/public_html/commons/btc-fetch.php
* * * * * sleep 35 && /usr/bin/php /home/cplpc/public_html/commons/btc-fetch.php
* * * * * sleep 40 && /usr/bin/php /home/cplpc/public_html/commons/btc-fetch.php
* * * * * sleep 45 && /usr/bin/php /home/cplpc/public_html/commons/btc-fetch.php
* * * * * sleep 50 && /usr/bin/php /home/cplpc/public_html/commons/btc-fetch.php
* * * * * sleep 55 && /usr/bin/php /home/cplpc/public_html/commons/btc-fetch.php

The catch: if your PHP script runs for longer then 5 seconds, you will end up with a lot of used (blocked) resources.

Idea taken from https://stackoverflow.com/a/9619449/9618184

Thanks @BinarWeb I managed to get this working. Does the job. My information it's recalling is only 1 line and that's the only one on the server so it's all good. Thanks :-) — aussiedan, Apr 11 '18 at 13:36

Cron Job not refreshing page every 5 seconds

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