whatis

The "whatis" command line tool is a utility that provides a brief description of a given command. It is primarily used in Unix-based systems and helps users quickly understand the purpose and function of various commands available.

When executed, "whatis" searches through a pre-built database known as the "whatis database" or "man pages." These man pages contain concise information about commands, including their usage and syntax.

The tool typically displays a single-line summary of the specified command, making it useful for quickly looking up commands without having to navigate lengthy documentation.

"whatis" is often paired with another command called "man," which stands for "manual pages." Once a user identifies a command using "whatis," they can then use "man" to access a more comprehensive documentation of that command.

Additionally, "whatis" can be used in conjunction with wildcards to search for commands with similar names or functions, providing users with a way to explore related commands or options they may not be aware of.

This command line tool is a handy resource for both beginners and experienced users who want to quickly get a high-level understanding of a command's purpose before delving deeper into its usage.