listen, listen1, tcp7, tcp9, tcp19, tcp21, tcp22, tcp23, tcp25, tcp53,
tcp110, tcp113, tcp143, tcp513, tcp515, tcp564, tcp565, tcp566, tcp567,
tcp993, tcp995, tcp1723, tcp17007, tcp17008, tcp17009, tcp17010,
tcp17013 - listen for calls on a network device
aux/listen [-iq] [-d srvdir] [-t trustsrvdir] [-n namespace] [net]
aux/listen1 [ -tv ] addr cmd [ args... ]
DESCRIPTIONlisten listens on a network for inbound calls to local services. Net
is the network protocol on which to listen, by default /net/tcp. The
services available are executable, non-empty files in srvdir or trust‐
srvdir. If neither srvdir nor trustsrvdir is given, listen looks for
executable files in /bin/service. Services found in srvdir are exe‐
cuted as user none; services found in trustsrvdir are executed as the
user who started listen. When changing user to none, a new namespace
is created, usually by executing /lib/namespace, but -n selects an
alternate namespace. Option -q suppresses affirmative log information.
Option -i suppresses the periodic scan of the service directories for
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 tcp565. These programs are
execed with arguments consisting of service (e.g., protocol (e.g., and
the directory of this network connection, with the network connection's
data file bound to /dev/cons and opened read/write as file descriptors
0, 1 and 2.
At least the following services are available in /bin/service.
tcp564 serve a piece of the name space using the Plan 9 file system
protocol, with authentication via Tauth (in attach(5)), no
encryption, and multiplex multiple users on a single connection
(used by srv(4), and also by Unix systems to see Plan 9 files).
serve a piece of the name space using the Plan 9 file system
protocol, with authentication at the start, optional SSL encryp‐
tion, and no multiplexing of users (typically used by cpu(1) and
import(4)). Not usable by user none.
like tcp17007, but serves the root of the tree, forgoing the
negotiation for which subtree to serve.
rx remote execution.
server for cpu(1) command.
server for old cpu(1) command for compatibility with old
tcp7 echo any bytes received (bit mirror)
tcp9 consume any bytes received (bit bucket)
tcp19 chargen service.
tcp21 FTP daemon
tcp22 ssh(1) `secure shell' encrypted terminal connection or file
tcp23 telnet terminal connection.
tcp25 mail delivery.
tcp53 TCP port for DNS.
tcp110 POP3 port.
tcp113 Ident port (always reports none).
tcp143 IMAP4rev1 port.
tcp513 rlogin terminal connection.
tcp515 LP daemon; see lp(8).
tcp565 report the address of the incoming call.
tcp993 Secure IMAP4rev1 port.
tcp995 Secure POP3 port.
PPTP (point-to-point tunnelling protocol) service.
At least the following services are available in /bin/service.auth, the
tcp566 validate a SecureNet box.
tcp567 Plan 9 authentication-ticket service.
Listen1 is a lightweight listener intended for personal use, modeled
from Inferno's listen(1). Listen1 announces on address, running cmd
args... for each incoming connection; the network directory is passed
in the environment as $net. Option -t causes listen1 to run as the
invoking user; the default is to become none before listening. Option
-v causes verbose logging on standard output. See /rc/bin/tlssrvtunnel
for an example.
by convention, TCP device bind point
SEE ALSOauthsrv(6), dial(2)BUGS
Srvdir, trustsrvdir and namespace must all be absolute path names.