whatis, apropos - give single line descriptions for manual pages
whatis [-a] title
Whatis lists the one line description from the whatis(5) database
describing the title given. It displays all the lines with the title
from the first whatis file that has those titles. It uses the same
search path as man(1).
Apropos searches through all whatis files for the given keywords. It
lists any line that has the keyword anywhere on the line.
-a Search all whatis files.
man(1), grep(1), whatis(5).
Kees J. Bot (firstname.lastname@example.org)