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
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