PHP - Email notification whenever a remote file changes

Question

I was wondering if there's a way to have a php script on my web server email me whenever a file from another web server changes.

For instance, there's this file that changes frequently: http://media1.clubpenguin.com/play/en/web_service/game_configs/paper_items.json

I blog about a game and that file is very important for creating post on updates before my competitors. I often forget to check it though.

Is there a way to have a script email me whenever that file updates, or check that file to see if it has updated, and email me if it has?

score 3 · Answer 1 · answered Feb 29 '12 at 08:10

Use crontab to setup checking script to run once a minute and compare this file with your locally stored version (or use md5 checksums instead - it will differ if file changes).

file_get_contents('http://url-to-file', 'checkfile.tmp');
if (md5(file_get_contents('lastfile.tmp')) != md5(file_get_contents('checkfile.tmp')))
{
    //copy checkfile to lastfile
    unlink('lastfile.tmp');
    copy('checkfile.tmp', 'lastfile.tmp'); 
    //send email or do something you want ;)
}

score 2 · Accepted Answer · edited Apr 17 '15 at 15:31

2

You need have this two files in same folder.

old.json
scriptForCron.php

In scriptForCron.php write:

$url='http://media1.clubpenguin.com/play/en/web_service/game_configs/paper_items.json';
$ch = curl_init($url);
curl_setopt($ch,CURLOPT_CONNECTTIMEOUT, 5);
curl_setopt($ch,CURLOPT_RETURNTRANSFER,true);
$execute = curl_exec($ch);

$fp=fopen('old.json','w+');
$oldjson=fread($fp,filesize('old.json'));

if($execute!=$oldjson){
 mail('your@mail.com','Yoohoo', 'File changed');
 fputs($fp,$execute);
}
fclose($fp);

And then add scriptForCron.php to cron job. You can ask hosting support for it.

edited Apr 17 '15 at 15:31

warfish

613
5
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answered Feb 29 '12 at 08:16

Narek

3,813
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Okay, did everything you said exactly. I'll make a test file to test it, for now everything seems to be in place. Thank you. – Nick Feb 29 '12 at 10:05

score 0 · Answer 3 · answered Feb 29 '12 at 08:10

This code does not check for updates in realtime - it would be pretty much impossible - but every 1 hour/minute.

First, save a file on your system which has the same contents as this. Name it any way, for example paper_items.json.

Now make a file named checkitems.php. Read the file which changes frequently, compare if it's contents are equal to your paper_items.json. If equal, nothing to do, if not, save the online file to your local paper_items.json and use PHP's mail() to email you something like "there was a change".

Finally, set up a cron job to run this every n (for example 1) hour or 1 minute, etc.

PHP - Email notification whenever a remote file changes

3 Answers3

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