Linux compression and archiving

I. Linux compression and archiving

1. Compression format: GZ, bz2, XZ, zip, Z

2. Compression algorithm: Different algorithm, compression ratio will also be different

3.Linux early compression command: Compress decompression uncompress

4.gzip:. GZ (Cannot compress the directory can only compress files, compressed will delete the original file)

Gzip/path/to/somefile

-D: The same function as the Gunzip command

-#:1-9, specify the compression ratio, the default is 6, compression ratio smaller compression speed faster

Gunzip

Gunzip/path/to/somefile.gz: The original file will be deleted when the decompression is complete

Zcat/path/to/somefile.gz: To view the contents of a text file without being pressed

5.BZIP2:. bz2 (cannot compress the directory can only compress the file, compressed will delete the original file)

Compression tool with a greater compression ratio than gzip, using a format approximation

Bzip2/path/to/somefile

-D: the same function as the bunzip2 command

-#: 1-9, default is 6

-K: Keep the original file when compressing

bunzip2/path/to/somefile.bz2

Bzcat to see the contents of a text file without being pressed

6.XZ:. XZ (default may not be installed, cannot compress the directory can only compress files, compressed will delete the original file )

Xz/path/to/somefile

-D: the same function as the unxz command

-#: 1-9, default is 6

-K: Keep the original file when compressing

UNXZ: Decompression

Xzdec: Unzip-unzip to screen

Xzcat: To view the contents of a text file without being pressed

7.zip: Both archived and compressed tools (can compress the directory)

Zip Filename.zip FILE1 FILE2 ...: Do not delete the original file after compression

Unzip Filename.zip

Archive: Archiving, archiving by itself does not imply compression

8.tar: Archive tool. Tar

-C: Create an archive file

-F File.tar: Archived files for operations

-X: Expand Archive

--xattrs: Preserves extended attribute information for files when archiving

-T: Do not expand the archive to directly see which files are archived

-ZCF: Archive and invoke gzip compression

-ZXF: Call gzip to unzip and expand Archive,-Z option to omit

-JCF: archive and call bzip2 compression

-JXF: bzip2 Extract and expand archive

-JCF: Archive and invoke XZ compression

-jxf: Tune Unzip and expand the archive with XZ

Cpio: Archive Tool

The 9.read command saves the user input values from the keyboard into a variable.

Read

-P "PROMPT" gives a hint

Exercise: Write a script

1. From the keyboard let the user enter two integers, the script can be and output

#!/bin/bash

#

Echo-n "Inpute-intergers:"

Read a B

echo "$a plus $b is: $[$a + $b]"

2. Calculates the and of all positive integers within 100

#!/bin/bash

Declare-i I=1

Declare-i sum=0

While [$I-le 100]; Do

Let sum+= $I

Let i++

Done

Echo $SUM

3. Convert user input characters to uppercase, except for quit:

#!/bin/bash

#

Read-p "Input Something:" STRING

while [$STRING! = ' quit ']; Do

echo $STRING | Tr ' A-Z ' A-Z

Read-p "Input Something:" STRING

Done

4. See if the Hadoop user is logged in every 5 seconds, sign in and sign in and exit; otherwise, the current time is displayed and the Hadoop is not logged in

#!/bin/bash

W.H.O. | grep "Hadoop" &>/dev/null

Retval=$?

While [$RETVAL-ne 0]; Do

echo "' Date ', Hadoop is not log."

Sleep 5

W.H.O. | grep "Hadoop" &>/dev/null

Retval=$?

Done

echo "Hadoop is logged in."

This article is from "Luo Chen's blog" blog, please be sure to keep this source http://luochen2015.blog.51cto.com/9772274/1638617

Linux compression and archiving