Linux learning (3) - Help command

table of Contents

Help command in Linux

Help command: man

Options Help command

Internal Shell Command Help

Detailed command help: info

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Video tutorial lesson but learning Mu: https://www.imooc.com/video/4306

This section summarizes the study and made notes.

Help command in Linux

Help command: man

grammar:

man 命令
	获取指定命令的帮助。如[man ls]查看ls命令的帮助。

man's level:

• 1: View command help

• 2: View function can be called to help the kernel

• 3: View help functions and libraries

• 4: View the help of a special file (mainly the files in the / dev directory)

• 5: View the profile help

• 6: View game help

• 7: View help other miscellaneous items

• Help system administrators to view the available commands: 8

• 9: Help Viewer and kernel-related documents

View command has that level of help:

man -f命令
    相当于
whatis命令
    例如：[man -5 passwd]、[man -4 null]、[man -8 ifconfig]等

See all the help and commands related to:

man -k命令
	相当于
apropos命令
	例如apropos passwd

Example 1: man ls command to view the help ls command.

Example 2: man -f ls command to view the ls command has what level of help

Example 3: apropos passwd command , all commands and passwd command to view the relevant help.

Options Help command

选项帮助：
命令	--help
	获取指定命令选项的帮助，如[ls --help]。

Example 1: ls --help command to see options to help the ls command, ls command to see what options there are.

 

Internal Shell Command Help

Shell内部命令帮助：
help shell内部命令
	获取shell内部命令的帮助，如[whereis cd]确定是否是shell内部命令；如[help cd]获取内部命令帮助。

Example 1: help cd command , see the help cd command.

 

Detailed command help: info

详细命令帮助info：
info 命令
	- 回车：进入子帮助页面（带有*号标记）
	- u：进入上层页面
	- n：进入下一个帮助小节
	- p：进入上一个帮助小节
	- q：推出

Example 1: info ls command to view the document ls command.