NLSADMIN(8) System Manager's Manual NLSADMIN(8)
listen, nlsadmin - network listener service administration for RFS
nlsadmin [ -mx ] [ -edr service_code net_spec ] [ -ikqsv net_spec ] [
-lt addr net_spec ] [ -a service_code [ -p modules ] -c command -y com-
ment net_spec ] [ -qz code net_spec ] [ -z code net_spec ] [ net_spec ]
This program is available with the RFS software installation option.
Refer to for information on how to install optional software.
nlsadmin configures, initiates and terminates network listener (listen)
servers for the local host. Each network (transport provider) has an
associated listen daemon to service it locally. The listen daemon for
each is configured separately. A listen daemon accepts network service
requests when they arrive, and spawns servers in response to those
requests. It can be used on any network (transport provider) that con-
forms to the transport provider specification.
nlsadmin can also report on the listener processes on a machine, either
individually (per network) or collectively.
Changing the list of services provided by the listener produces immedi-
ate changes, while changing an address on which the listener listens
has no effect until the listener is restarted.
nlsadmin without any options gives a brief usage message.
The net_spec argument to nlsadmin refers to a particular listen
daemon. Specifically, net_spec is the relative path name of the
entry under /dev for a given network.
-x Report the status of all of the listener processes
installed on this machine.
-e service_code net_spec
-d service_code net_spec
Enable or disable, respectively, the service indicated
by service_code for the specified network. The service
must have previously been added to the listener for that
network (see the -a option). When a listener is dis-
abled, processes serving prior requests continue until
-r service_code net_spec
Remove the entry for the service_code from that lis-
tener's list of services.
-i net_spec Initialize or change a listener process for the network
specified by net_spec. That is, create and initialize
the files required by the listener. Initializing a lis-
tener with this option does not start it running. The
listener must be initialized before assigning addressing
or services. Note: the listener should only be initial-
ized once for a given network.
-q net_spec Query the status of the listener process for the speci-
fied network. If the listener process is active, nlsad-
min exits with a status of 0. If no such process is
active, the exit code is 1. The exit code will be
greater than 1 if there is an error.
Start or kill, respectively, the listener process for
the indicated network. When a listener is killed, pro-
cesses that are still running as a result of prior ser-
vice requests will continue unaffected. The listener
runs under its own ID of listen with group ID (GID) adm.
This GID appear in the system password file /etc/passwd;
the HOME directory listed for the GID is concatenated
with net_spec to determine the location of the listener
configuration information for each network.
nlsadmin may be invoked by any user to generate reports,
but all operations that affect a listener's status or
configuration are restricted to the super-user.
-v net_spec Verbose. Report on the servers associated with
net_spec, giving the service code, status, command, and
comment for each.
-l addr net_spec Change or set the address for the general listener
service. This is the address generally used by remote
processes to access the servers available through the
listener (see the -a option). addr is the transport
address on which to listen, and is interpreted using a
syntax that allows for a variety of address formats. By
default addr is interpreted as the symbolic ASCII repre-
sentation of the transport address. An addr preceded by
a `\x' (BACKSLASH-X) lets you enter an address in hexa-
decimal notation. Note: addr must be quoted if it con-
tains any blanks. If addr is just a dash (`--'), nlsad-
min merely reports the currently configured address.
A change of address does not take effect until the next
time the listener for that network is started.
-t addr net_spec
Change or set the address on which the listener listens
for requests for terminal service. Otherwise, this is
similar to -l. A terminal service address should not be
defined unless the appropriate remote login software is
available; if such software is available, it must be
configured as service code 1 (see the -a option).
[-m] -a service_code -c cmd -y comment net_spec
Add a new service to the list of services available
through the indicated listener. service_code is the
code for the service, cmd is the command to be invoked
in response to that service code, comprised of the full
path name of the server and its arguments, and comment
is a brief (free-form) description of the service for
use in various reports. Note: cmd must be quoted if it
contains arguments for the server. Similarly, comment
must also be quoted, so as to appear to be a single word
to the shell. When a service is added, it is initially
enabled (see the -e and -d options).
If the -m option is specified, the entry is marked as an
administrative entry. Service codes 1 through 100 are
reserved for administrative entries, which are those
that require special handling internally. In particu-
lar, code 1 is assigned to the remote login service,
which is the service automatically invoked for connec-
tions to the terminal login address.
A service must explicitly be added to the listener for
each network on which that service is to be available.
This operation is normally performed only when the ser-
vice is installed on a machine, or when populating the
list of services for a new network.
-qz code net_spec
Query the status of the service with service code code
on network net_spec, Exit with a status of 0 if the ser-
vice is enabled, 1 if the service is disabled, or
greater than 1 on error.
-z code net_spec
Print a report on the server associated with net_spec
that has service code code, giving the same information
as in the -v option.
net_spec Print the status of the listener process for net_spec.
If the command is not run under the proper ID, an error message is sent
to the standard error, and the command terminates.
1 November 1988 NLSADMIN(8)