Synopsis:
   $key([<channel>|* [<channel> ...]])

Technical:
   This function displays the channel key for each channel specified (if
   any have a key assigned).  If a "*", or no channel, is specified, the
   current is assumed.  It has no effect for channels that you aren't
   currently on.

Practical:
   This function is used to fetch a channel's key.  Any number of channels
   may be specified, though the output could be confusing if only some
   actually have a key.  You must be on the channel(s) specified for the
   function to have any effect.

Returns:
   list of channel keys for given channels, or empty string if none or error

See Also:
   chanmode(6)