DZone Snippets: gzip code

Decompress several filetypes with a single script

zdenton (Zach Denton) — Fri, 18 Jul 2008 02:07:02 GMT

// Decompresses Z, gz, bz2, zip, rar, tar, and 7z with a single 'decompress' command



#!/bin/bash



# decompress - will decompress a file, regardless of compression type.



Z="compress -d"

gz="gunzip"

bz="bunzip2"

zip="unzip -qo"

rar="unrar x -id -y"

tar="tar xf"

7z="p7zip -d"



if [ $# -eq 0 ]; then

    echo "Usage: decompress file or files to decompress">&2

    exit 1

fi



for name

do

	if [ ! -f "$name" ] ; then

		echo "$0: file $name not found. Skipped." >&2

		continue

	fi



	if [ "$(echo $name | egrep '(\.Z$|\.gz$|\.bz2$|\.zip$|\.rar$|\.tar$|\.tgz$|\.7z$)')" = "" ] ; then

		echo "Skipped file ${name}: it's already decompressed." 

      		continue

	fi



	extension=${name##*.}



	case "$extension" in

		Z ) echo "Filetype is Z. Decompressing..."

		    $Z "$name"

		    ;;

		gz ) echo "Filetype is gz. Decompressing..."

		     $gz "$name"

		     ;;

		bz2 ) echo "Filetype is bz2. Decompressing..."

 		     $bz "$name"

		     ;;

		zip ) echo "Filetype is zip. Decompressing..."

		      $zip "$name"

		      ;;

		rar ) echo "Filetype is rar. Decompressing..."

		      $rar "$name"

		      ;;

		tar ) echo "Filetype is tar. Decompressing..."

              	      $tar "$name"

              	      ;;

		tgz ) echo "Filetype is tgz. Decompressing..."

              	      $tar "$name"

                     ;;

               7z ) echo "Filetype is 7z. Decompressing..."

                     $7z "$name"

	esac



done



exit 0

gzip pipe

cdvddt (Raphael Jolivet) — Sun, 15 Jun 2008 08:50:59 GMT

#! /usr/bin/python

from gzip import GzipFile
from StringIO import StringIO

class GZipPipe(StringIO) :
"""This class implements a compression pipe suitable for asynchronous
process.

Only one buffer of data is read/compressed at a time.
The process doesn't read the whole file at once : This improves performance
and prevent hight memory consumption for big files."""

# Size of the internal buffer
CHUNCK_SIZE = 1024

def __init__(self, source = None, name = "data") :
"""Constructor

@param source Source data to compress (as a stream/File/Buffer - anything with a read() method)
@param name Name of the data within the zip file"""

# Source file
self.source = source

# OEF reached for source ?
self.source_eof = False

# Buffer
self.buffer = ""

StringIO.__init__(self)

# Inherited constructor

# Init ZipFile that writes to us (the StringIO buffer)
self.zipfile = GzipFile(name, 'wb', 9, self)

def write(self, data) :
"""The write mzthod shouldn't be called from outside.
A GZipFile was created with this current object as a output buffer anbd it
fills it whenever we write to it (calling the read method of this object will do it for you)
"""

self.buffer += data

def read(self, size = -1) :
"""Calling read() on a zip pipe will suck data from the source stream.

@param size Maximum size to read - Read whole compressed file if not specified.
@return Compressed data"""

# Feed the zipped buffer by writing source data to the zip stream
while ((len(self.buffer) < size) or (size == -1)) and not self.source_eof :

# No source given in input
if self.source == None: break

# Get a chunk of source data
chunk = self.source.read(GZipPipe.CHUNCK_SIZE)

# Feed the source zip file (that fills the compressed buffer)
self.zipfile.write(chunk)

# End of source file ?
if (len(chunk) < GZipPipe.CHUNCK_SIZE) :
self.source_eof = True
self.zipfile.flush()
self.zipfile.close()
break

# We have enough data in the buffer (or source file is EOF): Give it to the output
if size == 0:
result = ""
if size >= 1 :
result = self.buffer[0:size]
self.buffer = self.buffer[size:]
else : # size < 0 : All requested
result = self.buffer
self.buffer = ""

return result

nginx gzip config

indiehead (John) — Fri, 18 Apr 2008 14:09:29 GMT



  # output compression saves bandwidth 

  gzip              on;

  gzip_proxied      any;

  gzip_http_version 1.1;

  #gzip_min_length   1100;

  gzip_comp_level   5;

  #gzip_buffers      4 8k;

  gzip_types        text/plain text/html text/xml text/css application/x-javascript text/xml application/xml application/xml+rss text/javascript application/atom+xml;

  #gzip_vary        on;

  #gzip_disable     "MSIE [1-6]\.";

unix, pack folder and contents with tar gz

assbach (assbach) — Mon, 04 Dec 2006 16:28:02 GMT



tar -zcvf packagename.tar.gz folder/

Enabling Zip compression with PHP

alex.bosworth () — Tue, 03 Jan 2006 19:52:22 GMT

// if you want to reduce the bandwidth bill and increase page load time for long pages - this PHP snippet will turn on gzip compression for those that support it.



function compress_handler($in_output)

{

  return gzencode($in_output);

}

if (strpos($_SERVER['HTTP_ACCEPT_ENCODING'],'gzip') !== FALSE)

{

  ob_start('compress_handler');

  header('Content-Encoding: gzip');

}

else

{

  ob_start();

}

Using gzip module

korakot (Korakot Chaovavanich) — Fri, 02 Sep 2005 22:22:44 GMT

Modified from this funny thread in c.l.p
http://groups.google.co.uk/group/comp.lang.python/msg/e53361331c23fd76



import gzip



zfile = gzip.GzipFile('somefile.gz')

content = zfile.read()

zfile.close()