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Questions tagged [gzip]

Gzip is any of several software applications used for file compression and decompression. The term usually refers to the GNU Project's implementation, "gzip" standing for GNU zip. It is based on the DEFLATE algorithm, which is a combination of Lempel-Ziv (LZ77) and Huffman coding.

Gzip is any of several software applications used for file compression and decompression. The term usually refers to the GNU Project's implementation, "gzip" standing for GNU zip. It is based on the DEFLATE algorithm, which is a combination of Lempel-Ziv (LZ77) and Huffman coding.

Gzip is based on the DEFLATE algorithm, which is a combination of LZ77 and Huffman coding. DEFLATE was intended as a replacement for LZW and other patent-encumbered data compression algorithms, which, at the time, limited the usability of compress and other popular archivers.

"Gzip" is often also used to refer to the gzip file format, which is:

  • a 10-byte header, containing a magic number, a version number and a time stamp
  • optional extra headers, such as the original file name
  • a body, containing a DEFLATE-compressed payload
  • an 8-byte footer, containing a CRC-32 checksum and the length of the original uncompressed data

source: wikipedia

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Grep-ing gzipped files

I have a set of 100 log files, compressed using gzip. I need to find all lines matching a given expression. I'd use grep, but of course, that's a bit of a nightmare because I'll have to unzip all files, one by one, grep them and delete the unzipped…
Julien Genestoux
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IIS 7.5 ignoring HttpCompression settings in web.config

I'm trying to enable dynamic compression for the mime type application/json. In applicationHost.config, I've made the following change:
I also tried…
Ben
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How do I turn on gzip in Apache2?

I simply did : sudo aptitude install apache2 And that's how my server is set up. No extra modules, no nothing. I'm on ubuntu jaunty.
Alex
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Enable both brotli and gzip on NGINX?

Is it possible to enable both gzip and brotli compression in NGINX? If the client supports both then return brotli, if only gzip / brotli then return the specicfied, and else if no support for gzip / brotli return plain text
otong
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nginx gzip Vary header together with existing Vary headers

I'm trying to active gzip compression and I have set the option gzip_vary on; to include the Vary: Accept-Encoding header. The problem is, my application is already seting a Vary: header. So the response is now having two Vary: headers, one from my…
Dennis C.
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Force Nginx to send Content-Length header for static files with gzip?

We're running Nginx 0.7.65[-1ubuntu2.3]. I've just noticed that when serving local static files using an alias directive and gzip on, the Content-Length header is not getting sent. Since it's serving files from the local filesystem, it shouldn't…
David Eyk
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How to tell if mod_deflate is actually working?

I have put the following in my http.conf file: # mod_deflate configuration # Restrict compression to these MIME types AddOutputFilterByType DEFLATE text/plain AddOutputFilterByType DEFLATE text/html AddOutputFilterByType…
Jay
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Apache deflates .xml.gz files

I noticed an error in google webmaster tools regarding a gzipped version of a sitemap. Turns out the sitemap.xml.gz file is gzipped twice: one upon creation (as it should be) and another time when being served. The .htaccess file has this…
Matteo Riva
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gzip not working on nginx for JSON responses

I'm trying to figure out why my JSON responses are not being gzip'ed. In my main ngninx.conf, I have: gzip on; gzip_vary on; gzip_proxied any; gzip_comp_level 6; gzip_buffers 16 8k; gzip_http_version 1.1; gzip_min_length 256; gzip_types …
Andrew Newby
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Error with gunzip during logrotate

I'm using logrotate to rotate my Symfony2 logs on my webserver. Everything works fine, but I wanted the old logs to be sent to me by emails. So, I added some line in my logrotate conf file as you can see below Logrotate…
Gary Olsson
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Verify if the files can be unzipped successfully from 7Zip archive

We want to 7zip many database files (mysql, Oracle, and SQL Server dumps), various standard files (excel, word, etc), but we are afraid that once we 7Zip them and delete the originals it can happen that archive is corrupted or it has some error and…
I don't know.
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Faster zlib alternatives

I wonder, if there are any faster builds of zlib around with more advanced optimizations? If it's possible to optimize it using SSE instructions or Intel C++ compiller, or some trick which were patented earlier (I know patents were a serious…
BarsMonster
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How does a web server/the http protocol handle version control and compression?

When a client browser requests a file from the web server, I know that some kind of check is performed, because the files needed to serve the web page may already be cached by the web browser. So, if a file exists in the cache, no files are sent.…
Sune Rasmussen
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Incorrect gzipping of http requests, can't find who's doing it

We're seeing some very strange mangling of HTTP responses, and we can't figure out what is doing it. We have an app server handling JSON requests. Occasionally, the response is returned gzipped, but with incorrect headers that prevent the browser…
Ned Batchelder
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nginx : enabling gzip compression based on hostname

I have a single machine running nginx serving http traffic for multiple domains(using same Lua codebase). For some of the domains I would like to enable gzip compression. Is it possible to enable gzip compression for specific set of domains? How?
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