PHP Check if page contains

Question

I'm looking for a quick code/function that will detect if a page contains a certain thing.

It's for a new project I'm working on.

Basically, the user will paste a simple javascript code into their pages, but I need to make sure they do.

I need a code that will scan through a specific webpage url and find the code I provided.

Thanks!

Go back through previous questions you've asked, and accept the best answer for each one - it's the big green tick to the left. — Sam Starling, Mar 14 '11 at 23:55

T.Todua · Answer 1 · 2020-01-14T10:46:36.813

2

You need to do the 2 things:

1) get the content of remote url

2) check if the content contains your string:

if ( stristr($content, 'your_desired_string') )
{
    echo ' Yes, found';
}

edited Jan 14 '20 at 10:46

answered Mar 29 '13 at 16:30

T.Todua

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Sam Starling · Answer 2 · 2011-03-14T23:57:03.043

2

You can get the contents of a URL as a string, and search the contents for that code:

<?php
function check_url($url) {
    $page = file_get_contents($url);
    $code = '<script src="http://example.com/test.js"></script>';
    if (strpos($page, $code) === FALSE) {
        return false;
    } else {
        return true;
    }
}
?>

You may want to swap that simple strpos out for a regular expression, but this will do the trick.

edited Mar 14 '11 at 23:57

answered Mar 14 '11 at 23:48

Sam Starling

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This fails when the script is found at the start of the webpage. And no ew regex! And no script MIME type given here :( – Lightness Races in Orbit Mar 14 '11 at 23:51
If the string is found at the start of the page, then the position is `int(0)`. It's a valid position, but your conditional treats it as a failure case. Use `===` to strictly compare against the `FALSE` that `strpos` returns on failure. – Lightness Races in Orbit Mar 14 '11 at 23:54
Ah yes, not got my head screwed on today! Thanks, have updated my answer. – Sam Starling Mar 14 '11 at 23:57

score 2 · Accepted Answer · answered Mar 14 '11 at 23:50

2

You want to scan through a webpage, not an URL! You get to the webpage through an URL. :)

<?php
$contents = file_get_contents("http://some.site/page.html");
$search   = <<<EOF
<script type="text/javascript">
alert('They must have this!');
</script>
EOF;

if (strpos($contents, $search) === FALSE) {
    echo "Naughty webpage!";
}
?>

Note, though, that programmatically skimming pages like this is generally considered bad form.

answered Mar 14 '11 at 23:50

Lightness Races in Orbit

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Won't whitespace throw this off? – drudge Mar 15 '11 at 00:13
@jnpcl: How so? If you're looking at whitespace at the end of the `$search = <<` line, then [no](http://codepad.org/lyzkAs8O). – Lightness Races in Orbit Mar 15 '11 at 00:17
@Tomalak: A few spaces before `alert()` or the closing `` tag? – drudge Mar 15 '11 at 00:18
1

This is easily thrown of by html indentation or CRLF variations. Better to strip all whitespace from the $subject and $search text beforehand. – mario Mar 15 '11 at 00:22
@jnpcl: The OP wanted to search for some text on a webpage. If there are spaces on the webpage that aren't in the search string then, sure, it'll fail. It's not a match. If the requirements are more complex than stated and some dynamic searching needs to be performed, then that's a different question entirely. – Lightness Races in Orbit Mar 15 '11 at 00:22
Works perfect for me. Thanks bud ! – ItsJhonny Apr 13 '21 at 07:44

score -1 · Answer 4 · answered Mar 15 '11 at 00:06

-1

there are great libraries for crawling websites like cURL but in your case it seems to be an overkill to use it. If you want to use the cURL library I recommend the Snoopy-class to you which is very simple to use.

Felix

answered Mar 15 '11 at 00:06

Felix Geenen

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Doesn't really answer the question, and _php_ has `file_get_contents` built-in so no need for a library. – Lightness Races in Orbit Mar 15 '11 at 00:23

PHP Check if page contains

4 Answers4