Uncompress a gzip file from CURL, on php

Question

Does anyone know how to uncompress the contents of a gzip file that i got with curl?

for example: http://torcache.com/torrent/63ABC1435AA5CD48DCD866C6F7D5E80766034391.torrent

responded

HTTP/1.1 200 OK
Server: nginx
Date: Wed, 09 Jun 2010 01:11:26 GMT
Content-Type: application/x-bittorrent
Content-Length: 52712
Last-Modified: Tue, 08 Jun 2010 15:09:58 GMT
Connection: keep-alive
Expires: Fri, 09 Jul 2010 01:11:26 GMT
Cache-Control: max-age=2592000
Content-Encoding: gzip
Accept-Ranges: bytes

then the compressed gzip,

i tried gzdecode but doesn't work , gzeflate as well doesn't they simply don't get any response, and the contents of the files are no more than 2k

score 87 · Answer 1 · edited May 22 '13 at 04:47

87

Just tell cURL to decode the response automatically whenever it's gzipped

curl_setopt($ch,CURLOPT_ENCODING, '');

edited May 22 '13 at 04:47

Alix Axel

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answered Jul 18 '10 at 20:55

mixdev

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Value should be empty string or encoding type. not int – redben Jul 12 '12 at 10:32
1

Thanks! Wouldn't this be a sensible default CURL setting? – Tom Carnell Jul 24 '13 at 19:21
1

@redben [My proposal](http://stackoverflow.com/review/suggested-edits/340974) was declined in 2011 and now AlixAxel's was approved. :( – mgutt Apr 02 '15 at 09:09
use 'curl_setopt($ch , CURLOPT_ENCODING, 'identity');' if you want to avoid encoding, per [link](https://curl.se/libcurl/c/CURLOPT_ACCEPT_ENCODING.html) – Bryan Sullivan Sep 30 '22 at 17:29

score 18 · Accepted Answer · answered Jun 09 '10 at 02:05

18

Use gzdecode:

<?php
    $c = file_get_contents("http://torcache.com/" .
        "torrent/63ABC1435AA5CD48DCD866C6F7D5E80766034391.torrent");
    echo gzdecode($c);

gives

d8:announce42:http://tracker.openbittorrent.com/announce13:announce-listll42
...

answered Jun 09 '10 at 02:05

Artefacto

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yes true, but I have php 5.2, and they say that gzdecode is available since 6.0 only I have a gentoo with php and zlib configured , and i can't seem to have available those gz functions. Any ideeas? :) – PartySoft Jun 09 '10 at 15:13
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Ok, i have a solution , no pretty because i had to write to a file the contents, and not only use a string : function gzdecode($data){ $g=tempnam('/tmp','ff'); @file_put_contents($g,$data); ob_start(); readgzfile($g); $d=ob_get_clean(); unlink($g); return $d; } and it works :) – PartySoft Jun 09 '10 at 15:27
@PartySoft That function is great! – barfoon Oct 21 '11 at 20:48
@PartySoft Thanks for that! Worked like a charm. Running 5.3.X and had no luck with [gzuncompress()](http://www.php.net/manual/en/function.gzuncompress.php). – donut Mar 17 '14 at 22:09
I suggest to use the $length parameter as it guards your script of insufficient memory errors. For example `$contents = gzdecode($contents, 10485760);` will stop decompression if the result will be more than 10 MB. I had several websites that were < 1 MB in gzipped size and after `gzdecode()` they raised to 30 MB! If you prefer CURLOPT_ENCODING you should try CURLOPT_WRITEFUNCTION if you are able stop the decompression result by that as well. I did not test it. – mgutt Apr 14 '15 at 11:37
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what the heck, no, just set CURLOPT_ENCODING to "gzip" and curl will automatically decompress gzip-encoded responses – hanshenrik Jun 25 '19 at 09:58

score 13 · Answer 3 · edited Dec 09 '19 at 22:45

13

libcurl offers a feature that makes it decompress the contents automatically (if built with zlib).

See the CURLOPT_ACCEPT_ENCODING option: https://curl.haxx.se/libcurl/c/CURLOPT_ACCEPT_ENCODING.html

edited Dec 09 '19 at 22:45

mbomb007

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answered Jun 15 '10 at 22:19

Daniel Stenberg

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score 1 · Answer 4 · answered Jun 09 '10 at 01:56

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Have you tried setting the header stating that you accept gzip encoding as follows?:

curl_setopt($rCurl, CURLOPT_HTTPHEADER, array('Accept-Encoding: gzip,deflate'));

answered Jun 09 '10 at 01:56

Oren Hizkiya

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he's already receiving it encoded, so I don't think declaring that he accepts it encoded would do any difference. I tried sending the server Accept-encoding: none and the server did not comply. – Artefacto Jun 09 '10 at 01:59

score 1 · Answer 5 · answered Jul 22 '11 at 21:03

1

With a zlib Stream Wrapper:

file_get_contents("compress.zlib://http://torcache.com/" .
    "torrent/63ABC1435AA5CD48DCD866C6F7D5E80766034391.torrent");

answered Jul 22 '11 at 21:03

Gordon

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score 0 · Answer 6 · answered Jun 09 '10 at 02:00

Have you tried gzuncompress or gzinflate?

gzdeflate compresses, the opposite of what you want. To be honest, I can't figure out how gzdecode differs from normal uncompressing.

There's also the cURL option CURLOPT_ENCODING:

The contents of the "Accept-Encoding: " header. This enables decoding of the response. Supported encodings are "identity", "deflate", and "gzip". If an empty string, "", is set, a header containing all supported encoding types is sent.

It seems to mean it'll automatically decompress the response, but I haven't tested that.

score 0 · Answer 7 · answered Aug 30 '11 at 12:35

You can do it with gzinflate (pretending that $headers contains all your HTTP headers, and $buffer contains your data):

if (isset($headers['Content-Encoding']) && ($headers['Content-Encoding'] === 'gzip' || $headers['Content-Encoding'] === 'deflate'))
    {
        if ($headers['Content-Encoding'] === 'gzip')
        {
            $buffer = substr($buffer, 10);
        }
        $contents = @gzinflate($buffer);
        if ($contents === false)
        {
            return false;
        }
    }

Uncompress a gzip file from CURL, on php

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