Php parse and monitor webpage for changes?

Question

How can I track changes to an external site? and displays the modified content? I am familar with php, *sql, linux/unix.

Similar to dailyrotation.org ?

Answer 1

Hi.

There is a free CMS PHP-based opensource product you can use:

http://rsinger.library.gatech.edu/

Otherwise, like the previous use said, store a local copy of each file. Periodically check each files for changes using the HTTP HEAD command. If there was a change, you can download the changed file under a new name then run a "diff" on the two files.

http://www.holomind.de/phpnet/diff.src.php

Resources for more PHP code can be found at sourceforge.net, php.net, and zend.com.

-Leon S

Answer 2

I've used something like this to make local copies of weather data on web sites. I used it to have a local cache, but it could provide a local version. I would suppose you could call the off site file and compare it to your local one. The function that is most important here is join('',@file($BaseURL)) that reads the off site file into the string $text.

You could also put the text in a database.


$cachefile = 'cache/KGKY.xml';
$BaseURL = "http:// www.weather.gov/ data/ current_obs /KGKY.xml";
$text = join ('', @file($BaseURL));
$fp = fopen($cachefile, 'w');
fwrite($fp, $text);
fclose($fp);

?>

NOTE:I've added spaces in that URI so it would display here at Yahoo! answers.