Dahne-linux Foundation-day02

Linux commands:

An instruction or program used to implement a certain type of function.

The execution of the command depends on the interpreter

Shell (interpreter) system default interpreter for/bin/bash

Execution process:
User Send command-interpreter-kernel-hardware

Mount Command:

Mount is to install/CD/DVD/partition/NAS/u disk and other network devices installed under a Linux directory, the various command tools to access the Linux directory to operate these devices.

Format: Mount device path mount point directory

Example: Mount/dev/cdrom/opt to mount the optical drive device to the/OPT

Ls/opt viewing content as CD-ROM contents

Uninstall command:

Format: Umount mount point Directory

Example: umount/opt

Ls/opt no content after viewing because the optical drive device has been uninstalled.

Common tips:

[Email protected] opt]# umount/opt
Umount:/opt: Target busy.
(In some cases, by lsof (8) or fuser (1), you can
Find useful information about processes that use this device)

Reason: Because you are now in a position under the/OPT, the system will think that someone is using. So the uninstallation is unsuccessful.

Output of the redirect command:

Overwrite redirects >

Append redirect >>

For example:

[[email protected]/]# hostname >/opt/1.txt output host name to 1.txt
[Email protected]/]#
[[email protected]/]# cat/opt/1.txt view 1.txt content

Localhost.localdomain

[Email protected]/]# ifconfig >>/opt/1.txt

Outputs the contents of the ifconfig to 1.txt, but does not overwrite the original content in 1.txt

Use wildcard characters:

For indeterminate document names, represented by special symbols

* Any number of characters

？ Single character

[A-z] multiple characters or one in a continuous range, if none is omitted,

{x, y, Z} multiple sets of different strings, full match

For example:

ls/etc/*.conf etc under the document ending with. conf

Documents starting with TTY under ls/dev/tty* Dev

Ls/dev/tty? A document that starts with a TTY and has only one character behind the TTY.

Ls/dev/tty[0-7] Dev starts with a TTY and the next character is a number within 0-7

ls/dev/tty{3,7,14} dev under Tty3, Tty7, TTY14

Case:

List/dev/tty20 to/dev/tty30

[[email protected] opt]# ls/dev/tty{2[0-9],30}
/dev/tty20/dev/tty22/dev/tty24/dev/tty26/dev/tty28/dev/tty30
/dev/tty21/dev/tty23/dev/tty25/dev/tty27/dev/tty29

To create a directory:

Format: mkdir-p/path/directory Name

For example

[[email protected]/]# mkdir-p/opt/a/b/c/d-p is created together with the parent directory

[[email protected]/]# ls-r/opt-r means recursive display
/OPT:
A

/OPT/A:
B

/opt/a/b:
C

/OPT/A/B/C:
D

/OPT/A/B/C/D:

To create an empty file:

Touch/opt/1.txt create 1.txt under opt

echo Command: Echo content

For example:

[[email protected]/]# echo Daskjfkjsad output the content directly on the command line

Daskjfkjsad

[[email protected]/]# echo 123 >/opt/2.txt 123 output to 2.txt and create 2.txt
[Email protected]/]#
[Email protected]/]#
[Email protected]/]# ls/opt/
1.txt 2.txt A
[[email protected]/]# Cat/opt/2.txt View the contents of/opt under 2.txt
123

Home directory:

~ Indicates home directory

~user represents the user's home directory

/root Administrator's Home directory

/Home Store user's house directory

For example

[Email protected]/]# Ls/home

Lisi Zhangsan
[[email protected]/]# useradd WANGWU Create Wangwu user
[[Email protected]/]# CD ~wangwu go to Wangwu home directory
[Email protected] wangwu]# Ls/home
Lisi Wangwu Zhangsan

cp-replication

Format: CP [option] source file destination Path

Common Command options:

-R Recursive replication directory must have this option

-P Keep the permissions modification time of source files and other properties unchanged

For example:

[[email protected]/]# cp-r/boot//opt/copy/boot to/opt
[Email protected]/]# ls/opt/
1.txt 2.txt a Boot

rm-Delete

Format: RM [options] File or directory

-R Recursive Delete

-F Force Delete

[Email protected]/]# ls/opt/
1.txt 2.txt a Boot
[[email protected]/]# rm-rf/opt/boot Force Delete/opt/boot
[Email protected]/]# ls/opt/
1.txt 2.txt A

mv-Move/Rename

Format MV source file destination Path

For example:

[Email protected]/]# ls/opt/
1.txt 2.txt A

[[email protected]/]# mv/opt/1.txt/opt/a move 1.txt to opt/a
[Email protected]/]# ls/opt/
2.txt A
[Email protected]st/]# ls/opt/a
1.txt

Renaming

For example:

[[email protected]/]# mv/opt/a/opt/c renamed a C to opt
[Email protected]/]#
[Email protected]/]# ls/opt/
2.txt C

Dahne-linux Foundation-day02