Bash Help Command

Let’s take a look at what bash is, and you can see it through whatis bash, apropos bash or man -k bash commands:

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bash is GNU's Bourne-Again SHell

The builtins is actually a soft link to bash-builtins:

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builtins is a soft link to bash-builtins

So we can use man builtins, info builtins, man bash-builtins or info bash-builtins commands to view bash’s built-in commands:

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after running man builtins command

help is bash’s built-in documentation command to see how built-in functions are used, for example help cd command:

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after running help cd command

We can use the help command to see how it works:

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help help command result

Info and Man Commands

The two commands, man and info, are not too different. They are both used to see how system commands are used and complement the help command.

We can view the purpose of the man command by executing the man man command or the info man command:

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man man and info man commands result

We can view the purpose of the info command by executing the man info command or the man info command:

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man man and info man commands result

When you use info or man to view the manual of bash built-in command cd, you don’t see it:

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after running info cd and man cd commands

We can take a look at which commands the info command provides a manual:

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after running info command

Summary

At the end, we can find out where info and man commands are and what they are, but we can’t find where help command is and what it is:

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don't see any info about help, but it's a bash built-in command

References Bash Reference Manual, WHEREIS, WHATIS, MAN, INFO

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