Describes what function a command performs.
whatis [ -M PathName ] Command ...
The whatis command looks up a given command, system call, library function, or special file name, as specified by the Command parameter, from a database you create using the catman -w command. The whatis command displays the header line from the manual section. You can then issue the man command to obtain additional information.
The whatis command is equivalent to using the man -f command.
Note: When the /usr/share/man/whatis database is built from the HTML library using the catman -w command, section 3 is equivalent to section 2 or 3. See the man command for further explanation of sections.
To find out what the ls command does, enter:
whatis ls
This produces the following output:
ls(1) -Displays the contents of a directory.
| /usr/share/man/whatis | Contains the whatis database. |
The apropos command, catman command, ls command, man command.