Linux study notes _ 3_common Linux commands _ 4 _ help commands

1. man [manual]: usrbinman gets help documents from commands or configuration files, view the help man [command or configuration file] of the command first. the moreegmanls command is called to view the help information of the ls command. manservices: view the help information of the configuration file services.

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

Obtain the command orConfiguration fileTo view the help documentation of the command first.

Man [command or configuration file] // call more

E.g. manls

Manservices

Appendix: There are nine types of help files in Linux

For example, man5 passwd // view the help of the configuration file

Default value: man1 passwd

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

Note: There is no big difference with man, except that the information is not presented in the same way, and this command is not available in UNIX systems.

3. get brief information about the relevant file:

Whatis [searchthe whatis database for strings]

/Usr/bin/whatisapropos

/Usr/sbin/makewhatis

Obtain the brief description of the index and find the basic purpose of this command.

Whatis [any keyword]

Appendix: [command]--help

It is mainly used to obtain command option information.

Apropos [file]

Used to obtain file configuration information, similar to: man-k [file]

Makewhatis

Create a database for whatis and apropos search. when the two commands are incorrect, whatisdatabase is not created.

4. help

View the file help of Shell built-in commands

For example, mancd and helpcd are different.

For more details about Shell, refer to other blogs.

Four days proficient in 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