Synopsis:
   who [<switch> [<arg>] [<switch> [<arg>] ...]] [<glob pattern>]

Description:
   The WHO command is used to retrieve detailed information about every
   user on irc.  For each user, it returns a single line containing
   their nickname, address (user@hostname), realname (IRCNAME), what
   their current channel is (and whether they have +o or +v there),
   whether they are marked away, and whether they are an irc operator.

   The data returned can be filtered by the client in a number of ways.
   It can be set to return only users who are marked away, people with a
   certain username, or users on a specific server.  For large queries,
   the data can also be conveniently dumped to a file for later viewing.
   
   The parameters to -end are as follows:
      $0   name of server queried
      $1   body of the query

Options:
   -operators            returns irc operators
   -lusers               returns non-irc operators
   -chops                returns channel operators
   -nick <nickname>      returns info for the given nickname only
   -name <username>      returns info for the given username only
   -host <hostname>      returns info for the given hostname only
   -server <servername>  returns info for the given servername only
   -diagnose             shows contents of the who queue for the server
                         of the current window
   -flush                removes all entries of the who queue for the server
                         of the current window
   -here                 returns users who are not away
   -away                 returns users who are away
   -line {...}           executes {...} for each line of output
   -end {...}            executes {...} at the end of the query
   -file <filename>      compare file contents to each line of output
   -u-i                  show invisible users (opers only, required
                         on the undernet)

Examples:
   To list all irc operators on servers from foo.com:
      /who -o -s *.foo.com

   To list the channel operators on channel #blah, which you are on:
      /who -c #blah

   To list all users from Russia, saving it to a file:
      /who -h *.ru -f ru.users

   To list all non-opers and say something at the end:
      /who -lusers -end { echo sheesh. that's alot of lusers! }

See Also:
   on(5) who; whois(2)

Restrictions:
   There are some limitations to the data returned by WHO.  For instance,
   it will not show users who have user mode +i set, unless that user's
   nickname is explicitly and unambiguously specified.  Similarly, it
   will mask channels with mode +p set, and will not show +s channels at
   all.  These limits do now apply, however, if the user in question is
   on a like channel with the querying client, or if the client is on a
   channel for which data is queried.

Other Notes:
   The various command line switches detailed above may be abbreviated,
   as shown in the examples, so line as the abbreviations are unambiguous.
   For instance, -n may not be used, since it matches -nick and -name.

   Use of the -file switch is not recommended, unless you know that the WHO
   output will be minimal.  This is because the client reads the entire file
   specified for each line of output, which is obviously quite inefficient,
   to say nothing of being rather abusing to your filesystem.

   The arguments from -line are identical to the arguments to on(5) who.
   In fact, -line works exactly like on(5) who. except it ALWAYS overrides
   on(5) who and disappears when the query is done. The -end is similar in
   that it overrides hooks to the 315 numeric.

   The -flush switch should *never* be used while a WHO request is still
   pending. The results are unpredictable. This is not a bug.