.TH LISTEN 8
.SH NAME
listen, dkcpu, dkcpunote, dkdiscard, dkecho, dkexportfs, dkrexexec, dkticket, dkwhoami, dksmtp, dkdcon, dklogin, dkguard, il7, il9, il565, il566, il17005, il17006, il17007, il17009, tcp2, tcp7, tcp9, tcp21, tcp23, tcp80, tcp25, tcp513, tcp515, tcp564, tcp565, tcp566, tcp17007, tcp6000 \- listen for calls on a network device
.SH SYNOPSIS
.B aux/listen
.RB [ -q ]
.RB [ -d
.IR srvdir ]
.RB [ -t
.IR trustsrvdir ]
.RI[ net
.RI [ name ]]
.SH DESCRIPTION
.I listen
announces itself to a network as
.I name
(by default the contents of
.BR /env/sysname )
and listens for inbound calls to local services.
.I Net
is the network device on which to listen, by default
.BR /net/dk .
The services available are executable files in
.I srvdir
or
.IR trustsrvdir .
If neither
.I srvdir
nor
.I trustsrvdir
is given,
.I listen
looks for executable files in
.BR /bin/service .
Services found in
.I srvdir
are executed as user
.BR none ;
services found in
.I trustsrvdir
as executed as the user who started
.IR listen .
Option
.B -q
suppresses affirmative log information.
.PP
Service names are made by concatenating the name of
the network with the name of the service or port.
For example,
an inbound call on the TCP network for port 565 executes service
.BR tcp565 ,
while a call on the Datakit network for service whoami executes service
.BR dkwhoami .
.PP
The following services are available in
.BR /bin/service .
.TF dkwhoami\ il565\ tcp565
.TP
.B "dkcpu il17005"
server for
.IR cpu (1)
command.
.TP
.B "dkcpunote il17006"
.BI  /proc/ pid /notify
forwarding for
.IR cpu (1).
.TP
.B dkexportfs il17007 tcp17007
serve a piece of the name space using the Plan 9 file system protocol,
with authentication (typically used by
.IR cpu (1)).
.TP
.B tcp564
like 17007, without authentication (used by Unix
systems to see Plan 9 files).
.TP
.B dkrexexec il17009
remote execution.
.TP
.B dkwhoami il565 tcp565
report the address of the incoming call.
.TP
.B tcp21
FTP daemon
.TP
.B tcp80
HTTP daemon; see
.IR httpd (8).
.TP
.B tcp515
LP daemon; see
.IR lp (8).
.TP
.B tcp6000
X-window callback
.TP
.B dksmtp tcp25
mail delivery.
.TP
.B dkdcon
research Unix terminal connection.
.TP
.B dklogin
generic terminal connection.
.TP
.B tcp23
.B telnet
terminal connection.
.TP
.B tcp513
.B rlogin
terminal connection.
.TP
.B tcp2
hold the connection open; sleep for a long time
.TP
.B dkecho il7 tcp7
echo any bytes received (bit mirror)
.TP
.B dkdiscard il9 tcp9
consume any bytes received (bit bucket)

.PP
The following services are available in
.BR /bin/service.auth .
.TF dkwhoami\ il565\ tcp565
.TP
.B dkguard tcp566
check a SecureNet box.
.TP
.B dkticket il566
authentication requests.
.SH FILES
.TF /env/sysname
.TP
.B /net/dk
by convention, Datakit device bind point
.TP
.B /net/il
by convention, IL device bind point
.TP
.B /net/tcp
by convention, TCP device bind point
.TP
.B /env/sysname
default announced name
.SH SOURCE
The source to
.I listen
is in
.BR /sys/src/cmd/aux/listen.c .
The other commands are
.IR rc (1)
scripts in
.BR /rc/bin/service .
.SH "SEE ALSO"
.IR dkconfig (8),
.IR auth (6),
.IR dk (3),
.IR dial (2)
