Whereis

Find the man page for a command

 * whereis -m genisoimage

genisoimage: /usr/share/man/man1/genisoimage.1.gz

List all binaries in /usr/bin which do 𝑛𝑜𝑡 have a man page

 * find /usr/bin -exec basename {} \; | xargs whereis -m | grep -v \/