Getting Help in Linux

Linux has many commands, and nobody needs to memorize every option. A more useful skill is knowing how to quickly find a command's description, syntax, options, and examples. Three common approaches are man, a command's own --help option, and Bash's help command for shell built-ins.

Use man to read manual pages

man is short for manual. Running man ls opens the manual page for ls. Manual pages commonly describe the command's purpose, syntax, options, and related information. In a real terminal, the page is usually displayed through a pager and you can press q to leave it.

$ man ls
$ ls --help
$ help cd

Use --help for a quick summary

Many commands support --help, such as ls --help and cp --help. It usually prints a compact reference directly in the terminal, which is useful when you only need to confirm an option. Not every program must use exactly the same help format, but --help is very common among GNU/Linux tools.

Use help for shell built-ins

Some commands are provided by Bash itself rather than by separate programs. cd is a common example of a shell built-in. For these commands, you can run help cd. To check whether a name is a built-in, executable, or alias, you can also use type, for example type cd.

man command A fuller manual page for deeper reference.

command --help A quick view of usage and common options.

help builtin Help for commands built into Bash.

Useful habit: Try command --help for a quick option lookup, use man command when you want fuller documentation, and use help for Bash built-ins such as cd.

Simulated terminal ready. Run commands and watch the filesystem on the right.