Question

Is it possible to search a remote page with a given URL for a given string, and indicate whether it exists, and if so, some indication of where it was found?

For instance, “Post Your Question” is included on this site https://stackoverflow.com/questions/ask.

In addition to searching just the page given by the URL, I would also like to search any JS or CSS links.

Answer 1

You can use the PHP Simple HTML DOM Parser to traverse through the contents of an html file.

Doing something like this:

$html = file_get_html('http://stackoverflow.com/questions/ask');
$htmlstring = $html->plaintext;
if(strstr($htmlstring, 'Post Your Question') === true)
  // do your stuff here

Then to get the url to css or js:

foreach($html->find('link') as $css) {
  $cssHref = $css->href;
  //load the css, parse or whatever
}
foreach($html->find('script') as $script) {
  $jsSrc = $script->src;
  //load js, parse or whatever
}

From there you can grab the css or js source url and do what you want with it.