php file_get_contents and &

Question

Hello all,

I'm trying to use php's file_get_content('a url');

The thing is if the url has '&' in it, for example

file_get_contents('http://www.google.com/?var1=1&var2=2')

it automatically make a requests to www.google.com/?var1=1&amp<no space here>;var2=2

How do I prevent that from happening?

Answer 1

You should try looking at the CURL libraries in PHP that would allow you to do something like:

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "http://mysite.com/file.php?blah=yar&test=blah");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$data = curl_exec($ch);
curl_close($ch);

You can then get the results from $data.

Answer 2

It looks like you in fact have a string with "&amp ;". You probably can't see it because you just show the output in the browser. You should use the browsers source view to make html elements visible.

Answer 3

The problem is most likely part of your PHP code. I suspect that what you think is happening is not actually happening.

I suspect that rather than the code you posted, you are probably grabbing part of that URL from a variable, such as:

$data = file_get_contents("http://example.com/?$myvariable");

Echoing that variable to the browser may be hiding the fact that you've inadvertently encoded special characters in a previous step, because in the browser an "&" is going to look like "&".

It's also possible that your file_get_contents() request is working correctly, and what you think is a problem with encoding the & sign may be a problem somewhere else - posting actual source code might help determining the problem.

Answer 4

Actually, there's nothing wrong with using & as field separator in query string. It is perfectly valid and even recommended by w3c. The problem with using & is that it interacts with character entity references (which has form &xxx;).

Also, see the note in PHP manual for url_encode() function:

Be careful about variables that may match HTML entities. Things like &amp, &copy and &pound are parsed by the browser and the actual entity is used instead of the desired variable name. This is an obvious hassle that the W3C has been telling people about for years. PHP supports changing the argument separator to the W3C-suggested semi-colon through the arg_separator .ini directive. Unfortunately most user agents do not send form data in this semi-colon separated format. A more portable way around this is to use & instead of & as the separator.

If you really don't like the & in your URLs, I'd suggest to check the setting of arg_separator directive in your php.ini file, although I'm not 100% sure it influences the way how file_get_contents modifies the URLs