Linux_ Compressed files and directories

Compression Decompression Command:

compression format: gz,bz2,xz,zip,z

Compression algorithm: Different algorithms, compression ratios will also be different:

Compress::filename. Z

Uncompress

Currently the most popular compression tools:

gzip:. GZ only files can be compressed

gzip/path/to/somefile/ Delete source files after compression

- D also means decompression

-# : [1-9], Specify the compression ratio, which is the default 6

Gunzip

gunzip/path/to/somefile.gz The source file is deleted when the extract is finished

zcat/path/to/somefile.gz without pressure, view the contents of the text file

bzip2:. bz2 than gzip compression tool with a greater compression ratio, using a format approximation

Bzip2/path/to/somefile source files are also deleted after compression

- D Unzip

      -# : [1-9], default 6

- k Keep Source Files

[Email protected]]# bzip2-d-K fstab.bz2

[Email protected]]# ls

ABC B2 fstab fstab.bz2

Bunzip2/path/to/somefile Unzip

Bzcat , in the case of uncompressed, view bzip2 the text class compressed file

XZ:. XZ

Xz/path/to/somefile source files are also deleted after compression

–d Unzip

-# [1-9], Specify compression ratio, default 6

- k source files can also be preserved when compressing

Unxz Unzip

Xzdec

Xzcat in the case of uncompressed, view XZ the text class compressed file

Zip: compression tool, compression ratio is not small. You can compress a directory , You can compress multiple files together, and compress the source files without deleting them

Zipfilename.zip FILE1 FILE2 ...

Unzip Filename.zip do not delete source files after decompression

Archive: Archive, the archive itself does not imply a compression

Tar: Archive-only No compression (do not delete source files after archiving)

- C Create an archive file

- F File.tar archived files for operations ( archive name must be established )

[Email protected]]# tar-cf Skel.tar Skel

[[Email protected]]# LS-LH

Total Dosage 40K

-rw-r--r--. 1 rootroot 10K 6 Month 15:28skel.tar

- x Restore archive, do not delete archive file

[Email protected]]# tar-xf Skel.tar

[Email protected]]# ls

Fstab.xz Skel Skel.tar

--xattrs preserves extended attribute information for files while archiving

- T do not expand archive See which files are archived

[Email protected]]# tar-cf V.tar a b c D

[Email protected]]# tar-tf V.tar

A/

b/

c/

d/

[email protected]]# xz V.tar (both archived and compressed)

[[Email protected]]# LS-LH

Total Dosage 48K

-rw-r--r--. 1 rootroot 184 6 Month 15:38v.tar.xz

-ZCF: Archive and Invoke gzip Compression

[Email protected]]# tar-zcf abcd.tar.gz a b c D

[Email protected]]# ls

A abcd.tar.gz b c D

-XCF called gzip Unzip and expand the archive

-JCF called bzip2

[Email protected]]# tar-jcf abcd.tar.bz2 a b c D

[Email protected]]# ls

A abcd.tar.bz2 b c D

-JXF Unzip

-JCF called XZ

[Email protected]]# tar-jxf abcd.tar.xz a b c D

[Email protected]]# ls

A ABCD.TAR.XZ b c D

-JXF Unzip

It's a lot of time when you unzip. -j or -j or - Z can not write

tar-ztfabcd.tar.gz do not expand directly look inside the content, the same here Z or J or J can omit

Cpio : Archive Tool

[Email protected]]# file/boot/initramfs-2.6.32-504.el6.i686.img/boot/initramfs-2.6.32-504.el6.i686.img: gzipcompressed data, from Unix, last Modified:mon June 6 17:35:04, Max compression

[[Email protected]]# cp/boot/initramfs-2.6.32-504.el6.i686.img/tmp Copy this compressed file to / tmp under

[[Email protected]]# mv Initramfs-2.6.32-504.el6.i686.img initramfs-2.6.32-504.el6.i686.img.gz

[email protected]]# gzip-d initramfs-2.6.32-504.el6.i686.img.gz Unzip

[Email protected]]# ls

A abcd.tar.gz b c D initramfs-2.6.32-504.el6.i686.img

[[Email protected]]# file initramfs-2.6.32-504.el6.i686.img View File Types to be Cpio Archived Files

Initramfs-2.6.32-504.el6.i686.img:ascii Cpio Archive (SVR4 with no CRC)

Exercise: Write a script

Let the user enter several file names from the keyboard, and the script can archive and compress the files into a single file:

#!/bin/bash

Read-p "Threefiles:" FILE1 FILE2 FILE3

Read-p "Destination:" DEST

Read-p "Compress[gzip|bzip2|xz]:" COMP

Case $COMP in

Xz

TAR-JCF${DEST}.TAR.XZ $FILE 1 $FILE 2 $FILE 3

;;

Gzip

tar-zcf${dest}.tar.gz $FILE 1 $FILE 2 $FILE 3

;;

BZIP2)

TAR-JCF${DEST}.TAR.BZ2 $FILE 1 $FILE 2 $FILE 3

;;

*)

echo "Unknown."

Exit 2

;;

Esac

This article from "Linux operation and Maintenance" blog, declined reprint!

Linux_ Compressed files and directories