In the Bash shell, the help command is used to display the built-in help documentation for a specific command or shell feature. Here’s how to use the help command:
You can type help followed by the name of the command or feature that you want help with. For example, to get help for the cd command, type:
help cd
Man
In Linux, the man command is used to display the manual pages (or documentation) for a specific command or program. Here’s how to use the man command:
Open a terminal window and start the Bash shell.
You can type man followed by the name of the command or program that you want to get help with. For example, to get help for the ls command, type:
man ls
This will display the manual page for the ls command, including a description of the command, a list of available options and arguments, and other useful information.
Use the up and down arrow keys to scroll through the manual page, or press the spacebar to move down one page at a time. Press q to exit the manual page and return to the shell prompt.
Apropos
If you’re not sure of the exact name of the command or program you need help with, you can use the apropos command to search for relevant manual pages. For example:
apropos file management
This will search the system’s manual pages for any commands or programs related to file management and display a list of matching manual pages.