whereis ls : Find the path of the ls command.whereis -b ls : Only search for binary files, ignoring other file types.whereis -m ls : Only search for documentation files, ignoring other file types.whereis -S ls : Only search for source code files, ignoring other file types.whereis -u ls : Only search for uninstalled files, ignoring other file types.whereis -a ls : Display all locations, including binary files, source code, and help manuals, etc.