utility uses a simple protocol based on
that provides an interface to
at several network sites.
It is supposed to return a friendly,
human-oriented status report on either the system at the moment
or a particular person in depth.
There is no required format and the
protocol consists mostly of specifying a single
can also be used to implement other protocols in conjunction with the
utility is started by
which listens for
requests at port 79.
Once connected it reads a single command line
terminated by a
which is passed to
utility closes its connections as soon as the output is finished.
If the line is null (i.e., just a
is sent) then
report that lists all people logged into
the system at that moment.
If a user name is specified (e.g.
response lists more extended information for only that particular user,
whether logged in or not.
in the command line include both
If a name is ambiguous, all possible derivations are returned.
The following options may be passed to
as server program arguments in
Enable debugging mode.
In debugging mode,
will not attempt any network-related operations on
and it will print the full
before executing it.
Suppress login information.
See the description of the
Enable secure mode.
Queries without a user name are rejected and
forwarding of queries to other remote hosts is denied.
The name of the host originating the query is reported via
at LOG_NOTICE priority.
Use an alternate program as the local information provider.
The default local program
By specifying a customized local server,
this option allows a system manager
to have more control over what information is
provided to remote sites.
will also set the environment variable
to the name of the host making the request.