Uncompress gzip compressed http response

Question

I'm using php's file_get_contents() function to do a HTTP request. To save bandwidth I decided to add the "Accept-Encoding: gzip" header using stream_context_create().

Obviously, file_get_contents() outputs a gzip encoded string so I'm using gzuncompress() to decode the encoded string but I get an error with data passed as argument.

[...] PHP Warning: gzuncompress(): data error in /path/to/phpscript.php on line 26

I know there is another function able to decompress gzipped data gzdecode() but it isn't included in my PHP version (maybe it is only available on SVN).

I know that cUrl decodes gzip stream on the fly (without any problem) but someone suggested me to use file_get_contents() instead of cUrl.

Do you know any other way to decompress gzipped data in PHP or why gzuncompress() outputs a Warning? It is absurd that gzuncompress() doesn't work as expected.

Notes: The problem is certainly about PHP: the HTTP request is made to Tumblr API that give a well-encoded response.

Answer 1

Found this working for me: http://www.php.net/manual/en/function.gzdecode.php#106397

Optionally try: http://digitalpbk.com/php/file_get_contents-garbled-gzip-encoding-website-scraping

if ( ! function_exists('gzdecode'))
{
    /**
     * Decode gz coded data
     * 
     * http://php.net/manual/en/function.gzdecode.php
     * 
     * Alternative: http://digitalpbk.com/php/file_get_contents-garbled-gzip-encoding-website-scraping
     * 
     * @param string $data gzencoded data
     * @return string inflated data
     */
    function gzdecode($data) 
    {
        // strip header and footer and inflate

        return gzinflate(substr($data, 10, -8));
    }
}

Answer 2

gzuncompress won't work for the gzip encoding. It's the decompression function for the .Z archives.

The manual lists a few workarounds for the missing gzdecode()#82930, or just use the one from upgradephp, or the gzopen temp file workaround.

Another option would be forcing the deflate encoding with the Accept-Encoding: header and then using gzinflate() for decompression.