The first chapter, the help of Linux get

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The first chapter, the help of Linux get

One, command line plus options

Built-in commands:

Help COMMAND

Example:

Help CD

External command:

COMMAND--help

command-h

To determine the command type:

type COMMAND

The results shown are:

[[Email protected] ~]# type CDCD is a shell builtin# built-in command [[email protected] ~]# type susu is/bin/su# external command [email protecte D] ~]# type Lsls is aliased to ' ls--color=auto ' # alias

Ii. use of the Command Manual (manual)

Format:

Mans COMMAND

Man number COMMAND

Example:

Man kill

Man 2 Kill

Note: If you do not add a number , the default starting from 1 , the number of numbers to open the first chapter

Numbers generally have the following categories:

1 Commands (Programs)

User commands

instructions or executables that the consumer can manipulate in the shell environment (/bin,/usr/bin,/usr/local/bin)

2 System calls

System calls

As the name implies, the system core can call functions and tools, etc.

3 Library calls

Library files

Some of the commonly used functions (function) with library files (library) , most of C 's

4 special files (devices)

Special Files ( device file )

device files, usually located in /dev

5 File formats and conventions

Document formats and specifications

specification formats for some profiles, such as /etc/passwd

6 Games

Game

7 Conventions and miscellaneous

Miscellaneous

8 System Management Commands

Manage Commands

instructions available to system administrators (/sbin,/usr/sbin,/usr/local/sbin)

9 Kernel routines [Non standard]

with Kernel ( kernel ) related files

The contents of the man page are roughly divided into the following sections:

<> : Required []: Optional ... : Multiple times can occur | : Choose one More {}: Grouping

NAME Brief instruction, information name Description

Synopsis Brief Introduction to instruction release syntax (syntax)

DESCRIPTION A more complete description of the important

OPTIONS for the Synopsis section, there is an enumeration of all the available option descriptions

COMMANDS When this program is executed, the instructions that can be issued in this program

FILES The configuration file associated with this command

See ALSO refer to the additional instructions

EXAMPLE Some examples that can be consulted

Man-related actions

SPACEBAR to turn down one page

[PageDown] turn down one page

b turn up one page Memory skills:b key above the SPACEBAR

[PageUp] turn up one page

Enter line down

K- up line memory tip: In front of the Enter key

[Home] to the first page

[End] to the last one

/string search string down

string Up Search

N,n continues the search for the next string,n forward,n Reverse

Q Exit

Man-related instructions

Man-f Mans find out in the system documentation that the chapters related to man are listed

Man-k Mans find the system documentation that contains the man keyword will be listed

Whatis [ instruction or material ] equivalent to man–f

Apropos   [ instruction or information ] equivalent to Man–k

Note : These two special instructions must be established Whatis database.

Use the following directives to establish:

Man db

(centos7 Use this command later, previously using makewhatis)

( in particular, minimal installation needs to be performed once )

third, online documentation Info

use similar to man, but more detailed than the man command, generally used less

Iv./usr/share/doc

v.Baidu,Google, and official documents

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The first chapter, the help of Linux get