PHP code scraping a URL suddenly stopped working - php

Question

$url = 'the web address I want to get the first and second numbers close to $' ;
$str = file_get_contents($url);
preg_match_all('/ ([$]) *(\d+(:?.\d+)?)/', $str, $matches, PREG_SET_ORDER);
$i=0;
foreach ($matches as $val) {
if($i==0) $first=$val[2] ;
if($i==3) $second=$val[2] ;
$i++;
}
$bad_symbols = array(",", "."); $first = str_replace($bad_symbols, "", $first);
$bad_symbols = array(",", "."); $second = str_replace($bad_symbols, "", $second);
echo $first . "</br>";
echo $second;
it worked fine till yesterday
what could be the problem?

Answer 1

I see at least two possible explanations :
The HTML of the site has changed ; maybe only a little bit -- but enough to get you in trouble.
You could test for the return value of preg_match_all
if it's false, it means your regex didn't match -- which may indicate the content of the HTML pageis not the same...
Then, you might have to modify your regex
The admin of the server (or it can be done in the code generating the page) has banned you
Maybe the website has detected it was scraped by you (either because you were going too hard on their server, or they saw their content on your site)
And they banned your IP (for instance)
To detect that, try to get the return value of file_get_contents ; if it's false, it might be the cause of the problem
Can you try getting that HTML page from your server, using wget in command-line ?
A third one, as suggestd by others : maybe the configuration of your server has changed, and you can't use file_get_content over HTTP anymore...
A solution would be to use curl, for instance
Check in your configuration the allow_url_fopen directive
If you activate error_reporting (see also), you might also get some informations that could prove usefull...

Answer 2

Maybe system administrator has changed allow_url_fopen directive, that means you can't access files that are not on your server. Check what file_get_contents() returns, because you gave us very little information about error.
Another problem, as mentioned above, could be that remote site has been changed :)