Linux Foundation-linux Command help Rollup

Get internal command help?

Help COMMAND

Get External command help?

COMMAND--help

PS: According to the type command, you can tell that command is internal/external

eg: [[email protected] ~]# type history

History is a shell builtin #则表示history为一个shell内部命令

We can use the help history to get assistance for this command

Plays----man command----

Man is manual, the manual means

Man has 1-9 chapters and invokes commands as follows:

Man [#] COMMAND

When no [#] is specified, the available chapters are called by default

The contents of the 8 chapters are as follows:

1. User commands

2. System calls

3. Library calls

4. Device files

5. Configuration Files

6. Games

7. Miscellaneous

8. Management commands

Whatis command--

Query command has several man chapters

[Email protected] ~]# Whatis ifconfig

Ifconfig (8)-Configure a network interface #显示ifconfig命令只有8章节

# #whatis命令根绝数据库执行查找操作, this library is updated periodically for the system; can be updated manually using Makewhatis

The paragraph of the Man Handbook:

Name: Command names

DESCRIPTION: A detailed description of the command function

Options: All option

Synopsis: Using formats

EXAMPLES: Using the example

Files: Configuration files related to the current command

See ALSO: Other manuals available

The Man Handbook format character:

[]: can be omitted

<>: not omitted

|: TWO Select one

...: homogeneous content can appear multiple

Man's use mechanism:

SPACEBAR: Flip a screen like a file tail

B: a screen like a file header page

Enter: Turn back one line

K: turn forward one line

String Search:

/keyword: Searching backwards from the file head

Keyword: Search forward from the end of the file

N: Shows the next found

N: Displays the last found

Man's exit

Q

The addition of the man command--

Use info only when man can't get enough information or wants to know the program's development history

Info command: Get online documentation

Many applications come with help documentation:/usr/share/doc

ChangeLog: Changes in program version upgrades

Install: Installation Method description

README: Instructions for use of the program

Official documents for mainstream distribution

Redhat, SuSE, Debian

Redhat:http://www.redhat.com/docs

Exercise: Get how to use the following command

Shutdown, date, Hwclock, Ntpdate, reboot, Halt, who, WhoAmI, which, hash

How to shut down, how to restart, such as restart at a specified time

Shutdown-h

-R

-C

Time format

Now

+m

hh:mm

Tips:type View the file type, use the corresponding Help method to view (or--help or man), such as with man, you can use Whatis to view the man chapters supported by the command, read the command format, determine the required parameters and optional parameters

This article is from the "Richier" blog, make sure to keep this source http://richier.blog.51cto.com/1447532/1650405

Linux Foundation-linux Command help Rollup