How do I get brief description of command on linux?

[hoodedvul]

Also see: Man page for whatis.

Using the whatis command.

$ whatis uuidgen
uuidgen (1)          - create a new UUID value
$ whatis unshare
unshare (1)          - run program with some namespaces unshared from parent
unshare (2)          - disassociate parts of the process execution context