Shulou(Shulou.com)06/01 Report--

I. View the contents of the file

View file contents cat command

Cat command

Purpose: display the contents of the file

Cat [option] file name...

Cat-n file name

Display the contents of the file and display the line number

More command

Purpose: full-screen paged display of file contents

Interactive operation method

Press Enter to scroll down line by line

Press the spacebar to flip down one screen

Press Q key to exit

More [option] file name...

Less command

Purpose: same as more command, but with more extended functions

Interactive operation method

Page Up page up, Page Down page down

Press the "/" key to find the content, "n" next content, "N" last content

Other functions are basically similar to the more command

Less [option] file name...

Tail command

Purpose: view a small portion of the end of the file (10 lines by default)

Tail-n file name...

Displays the specified number of rows at the end

Tail-f file name: orbit file changes

Wc command

Purpose: information such as the number of words in the statistics file (Word Count)

Common command options

-l: count the number of rows

-w: count the number of words

-c: count the number of bytes

Wc [options]... Target file.

Wc-l / etc/passwd to see how many users there are in the system

How much information does wc-l / var/log/secure have related to user operations?

The grep command (regular expressions are supported) and sed,awk

Purpose: find and display the line containing the specified string in the file

Common command options

-I: ignore case when looking up

-v: reverses the lookup and outputs lines that do not match the lookup criteria

Find condition settin

The string to be found is enclosed in double quotation marks

"^." Denote with. At the beginning, ". $" means with. End

"^ $" represents a blank line

Grep [options]... Find condition object file

2. Compress commands gzip and bzip2

Gzip command, bzip2 command

Purpose: make compressed files and unzip compressed files

Common command options

-9,-d

Gzip [- 9] filename...

Bzip2 [- 9] filename...

Compressed file in gzip-d. GZ format

Compressed file in bzip2-d .bz2 format

Please note:

Gzip/bzip2 compresses the object name, generates a compressed package and deletes the original file, which can only compress the file, not the compressed directory.

For example:

Bzip2 anaconda-ks.cfg

Gzip anaconda-ks.cfg

The gzip and bzip2 commands use different compression algorithms

Generally speaking, the compression efficiency of bzip2 is better.

Generate a large file

Dd if=/dev/zero of=big.txt bs=1M count=50

Gunzip command

Gunzip is equivalent to gzip-d

Gzip-d mkfile.gz

Or

Gunzip mkfile.gz

Bunzip2 command

The usage of bzip2 and bunzip2 commands is basically the same as that of gzip and gunzip commands.

Tar command (package directories and files and compress them)

Purpose: making and releasing archival documents

Common command options

-c,-x,-v,-f,-p,-t,-C,-z,-j

-c means packing

-x means unpacking

-v display details

-f specify the file name

-p keep permissions

-t test

-C specifies the decompression directory

-z calls compression algorithm gzip

-j calls the reduction algorithm bzip2

Tar [options]... Archive file name source file or directory

Tar [options]... Archive file name [- C target directory]

Tar czvf yasuob35.tar.gz / root/b35

Tar cjvf yasuob35.tar.bzip2 / root/b35/

Tar xzvf yasuob35.tar.gz-C dd36

Note: the relative path is used to compress the data, and the decompression will appear in the current working directory, so the operation is safer.

Assignment:

1. Count the number of users in the system; display the lines at the end of bash in the user configuration

2. Create a new directory yasuo in / root, and use two compression methods to compress the files of / etc/*.conf type into packages, package names peizhi.tar.gz and peizhi.bz2.

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