Is there a way to pass --compressed into PHP's curl_setopt()?

Question

When using curl, I'm seeing a difference in behaviors on the server I'm hitting depending on if I passed --compressed as an argument or not.

I'm already setting the Accept-Encoding header to gzip,deflate,sdch:

    curl_setopt( $ch, CURLOPT_ENCODING, 'gzip,deflate,sdch' );

I've also tried setting the encoding to empty string: '' since that supposedly means any type compression is supported.

However, if I've pass --compressed via the command line, the content type I get back is: gzip. If I don't pass in --compressed, the content type I get back is text/html;charset=UTF-8

Using PHP's curl_exec(), I can't ever seem to get it to return a content-type: gzip.

=====

Let me clarify what I'm trying to accomplish. When I run the following command: curl -I http://someserver.com --compressed gets me content-type: gzip

Running the same command curl -I http://someserver.com without --compressed gets me content-type: text/html;charset=UTF-8

Trying to do this in PHP:

$ch = curl_init();
curl_setopt( $ch, CURLOPT_URL, "http://someserver.com" );
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, 1 );

// I've tried excluding this line, setting it to gzip, and empty string
curl_setopt( $ch, CURLOPT_ENCODING, '' ); 
curl_setopt( $ch, CURLOPT_HEADER, 1);

curl_exec( $ch ) );
$content_type = curl_getinfo( $ch, CURLINFO_CONTENT_TYPE );

No matter what I try, I'm getting $content-type = text/html;charset=UTF-8 and not gzip

Answer 1

Removing the CURLOPT_ENCODING option (so curl doesn't auto-decode) and putting the accept-encoding option in the header manually should do the trick :

curl_setopt($ch, CURLOPT_HTTPHEADER, array(
    'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
    'Accept-Encoding: gzip, deflate',
    'Connection: Close'
));

Answer 2

Not all serves around the world provide the compressed content as a response. Through the option CURLOPT_ENCODING you can only ask for compressed content from the server. But server will return you plain html if it has not implemented the mechanism. You can try with other random websites which provides compress content. For example youtube.com(probably).