Linux Common Commands (second edition)--HELP commands

Help commands

1,man[manual]:/usr/bin/man

Get help for a command or profile , prioritize help for commands

Format: Man [ command or Profile ] #会同时调用 more

e.g.

Man ls# See Help for LS command

Help information for Man services #查看配置文件Services

Attached-the Help files in the Linux system are divided into nine types :

Example: Man 5 passwd// Help to view configuration files

Default: Man 1 passwd

2,info[information]: /usr/bin/info

Description: There is no big difference between the man and the man , except that the information is presented in a different way, and there is no such command in the UNIX System.

3, get the relevant documents short information:

1) Whatis[search The Whatis database for complete words.]

Format: whatis [ any keyword ]

# Get a short description of the index to find the most basic use of this command

such as: Whatis apropos

2) Apropos[search the Whatis database for strings.]

Format :apropos [ any keyword ]

# used to get configuration information for a file similar to:man-k [ file ]

Attached-but these two sets of commands must be executed correctly, the whatis database has to be created , and the command needs to be rooted . Identity Run

/usr/sbin/makewhatis

# When an error occurs using these two commands , the whatis database is not established

With the-[ command ] --help# is primarily used to get the option information for a command

Apropos [ file ]

4. Help #查看 The shell's built-in command files

For example: Man CD differs from Help CD

Attached-man bash# can be used to see What built-in commands the Shell contains

Also-for other shell explanations, please refer to the other blogs-"Four days of shell Programming" series:

http://blog.csdn.net/zjf280441589/article/details/17455515

http://blog.csdn.net/zjf280441589/article/details/17467069

http://blog.csdn.net/zjf280441589/article/details/17487351

http://blog.csdn.net/zjf280441589/article/details/17503985

Linux Common Commands (second edition)--Help commands