Linux help Information Retrieval

Linux Commands include built-in commands and external commands. The following describes how to get help from these commands.

I. built-in commands

Usage:

Help COMMAND

Determine built-in commands:

Type COMMAND

Obtain all built-in commands of the system:

Compgen-B

Man builtin

Ii. External commands

1. manual

The manuals for different types of commands or configurations are located in different chapters:

1) user commands

2) system call

3) database call

4) special files and Device Files

5) File Format configuration file)

6) games

7) miscellaneous)

8) management commands

Usage:

Man COMMAND

Man-k KEYWORD: displays a list Of all keywords-related manuals

Whatis COMMAND

Makewhatis immediately retrieves the whatis Database

2. info page

Use (? Info help information ):

Info COMMAND

3. Brief help

Usage:

COMMAND -- help

COMMAND-h

4. Official documents

Http://www.redhat.com/docs/

5. Other Related Documents

For example: ReadMe, Install, ChangLog,/user/share/doc/ls-VERSION

6. www.google.com

This article from the "Linux/Unix O & M Technology" blog, please be sure to keep this source http://wangyc.blog.51cto.com/31193/1304891