Cat commands in Linux; decompression command __linux

Learned after really very useful, very fast.

Cat has three main functions: 1. Displays the entire file at once.
$ cat FileName


2. Create a file from the keyboard.
$ cat > FileName
You can only create new files, and you cannot edit existing files.


3. Merging several files into one file.
$cat file1 file2 > file


Cat specific command format: Cat [-ABEENSTTUV] [--help] [--version] FileName
Description: Connect the file string to the basic output (screen or add > FileName to another file)
Parameters:
-N or –number the number of rows for all outputs starting with 1
-B or –number-nonblank and-n are similar, except for blank lines not numbered
-S or –squeeze-blank is substituted for a line of blank lines when a blank line with two consecutive lines is encountered
-V or –show-nonprinting


Example:
Cat-n linuxfile1 > Linuxfile2 the linuxfile1 file with the line number and enter linuxfile2 this file.
Cat-b linuxfile1 linuxfile2 >> Linuxfile3 appends the contents of Linuxfile1 and Linuxfile2 files to Linuxfile3 after the line number (blank lines are not added).

Cat/dev/null >/etc/test.txt This is for emptying/etc/test.txt archive content

. tar
Unpack: Tar xvf Filename.tar
Packing: Tar cvf filename.tar dirname
(Note: Tar is packed, not compressed.) ）
———————————————
. gz
Decompression 1:gunzip filename.gz
Decompression 2:gzip-d filename.gz
Compression: gzip FileName


. tar.gz and. tgz
Decompression: Tar zxvf FileName.tar.gz
Compression: Tar zcvf FileName.tar.gz dirname
———————————————
. bz2
Decompression 1:bzip2-d filename.bz2
Decompression 2:BUNZIP2 filename.bz2
Compression: Bzip2-z FileName


. tar.bz2
Decompression: Tar jxvf FileName.tar.bz2
Compression: Tar jcvf FileName.tar.bz2 dirname
———————————————
. BZ
Decompression 1:bzip2-d filename.bz
Decompression 2:BUNZIP2 filename.bz
Compression: Unknown


. tar.bz
Decompression: Tar jxvf FileName.tar.bz
Compression: Unknown
———————————————
. Z
Decompression: uncompress filename.z
Compression: Compress FileName
. Tar. Z


Decompression: Tar zxvf filename.tar.z
Compression: Tar zcvf filename.tar.z dirname
———————————————
. zip
Decompression: Unzip Filename.zip
Compression: Zip Filename.zip dirname
———————————————
. rar
Decompression: rar x Filename.rar
Compression: rar a filename.rar dirname
———————————————
. Lha
Decompression: Lha-e Filename.lha
Compression: Lha-a Filename.lha FileName
———————————————
. rpm
Unpack: Rpm2cpio filename.rpm | Cpio-div
———————————————
. deb
Unpack: ar p filename.deb data.tar.gz | Tar zxf-
———————————————
. Tar. tgz. tar.gz. Tar. Z. tar.bz. tar.bz2. Cpio. rpm. Arj. Lha. Lzh. Lzx. Lzs. SDA. cab SFX. Lnx. P. SLP. Zoo. it. Sit. Sea
Decompression: sEx x filename.*
Compression: SEx a filename.* FileName


Sex just call the relevant program, itself and no compression, decompression function, please note.


gzip command
Reducing file size has two obvious benefits, one is to reduce storage space, and the other is to transfer files over the network, you can reduce the transmission time. Gzip is a regular use of Linux in the file compression and decompression of the command, both convenient and useful.


Syntax: gzip [option] Compress (uncompress) file name the options for this command have the following meanings:


-C writes the output to the standard output and retains the original file. -D Unzip the compressed file. -L Displays the following fields for each compressed file: The size of the compressed file, the size of the uncompressed file, the compression ratio, the name of the uncompressed file-R recursively finds the specified directory and compresses all of its files or is uncompressed. -T test to check that the compressed file is complete. -V displays filename and compression ratio for each compressed and decompressed file. -num adjusts the speed of the compression with the specified number num,-1 or--fast represents the fastest compression method (low compression ratio),-9 or--best represents the slowest compression method (high compression ratio). The default value for the system is 6. Instruction instance:


Gzip *% compresses each file in the current directory into a. gz file. GZIP-DV *% extracts each compressed file in the current directory and lists detailed information. Gzip-l *% details the information for each compressed file in Example 1 and does not understand the pressure. GZIP usr.tar% Compressed tar backup file Usr.tar, at which time the compressed file extension is. tar.gz.