Linux help Command--help,man,whereis introduction

As a novice, when you start using Linux, it's hard to remember many commands, and the Linux help commands come in handy.

1.help command

First of all, the Linux internal commands and external commands, internal commands are encapsulated in the shell, external commands on the Linux system can find the corresponding location. Use type to learn that a command is an internal command, an external command, or a keyword, such as:

> type CDCD is a shell builtinlsls hashed (/bin/ls)

You can view all internal commands by typing the help command in the shell. When you use Help to view internal commands, simply type "help command", and if you need to view external commands, type "command--help".

// enumerate the commands in the shell > Help // describes the use of the internal command pwd command pwd // description of the use of the external command LS > ls --help

2. Man command

Shorthand for the manual manual, which provides an online Help manual for commands, can be replaced by the info command, as info provides an online Help manual with the latest updated system information.

// List The complete description of the LS command, including features, options, examples, and so on, as detailed in the online manual . Mans ls

3. Whereis command

// View the location of a command Whereis pwd/bin/pwd

Linux help Command--help,man,whereis introduction