The Service Access Facility

The port monitor administrative file

Each port monitor has its own administrative file, /etc/saf/pmtag/_pmtab, that you maintain using pmadm(1M). Whenever you make changes to a port monitor on your system, pmadm records those changes by adding, deleting or modifying the relevant entries. Each type of port monitor has separate administrative files. Changes to a file are made only by the appropriate port monitor (ttymon, listen, or one you created) which immediately rereads the file whenever a change is made.

Each entry in /etc/saf/pmtag/_pmtab indicates:

Each entry within the file is uniquely identified by a service tag. The combination of a service tag and a port monitor tag (pmtag) is a unique string that defines an instance of a service.

NOTE: A single service tag may be used in more than one file to identify the same service under multiple port monitors. In other words, for consistency and recognition, the same service tag may be used in more than one port monitor administrative file.

The entry must also contain port monitor-specific information that is meaningful for a particular port monitor. For example, entries for ttymon port monitors may include prompt strings.

To add information to a port monitor administrative file, execute the command for the appropriate port monitor type:

used in conjunction with sacadm for a ttymon port monitor

used in conjunction with pmadm for a listen port monitor

If you are installing new software for a network service or application, it may include an installation procedure that automatically adds the appropriate entries to the port monitor administrative file.

Also note that additions to both the SAC and port monitor administrative files are made cooperatively, since there must be an entry in /etc/saf/_sacadm for each pmtag associated with a port monitor administrative file. See ``Adding a port monitor'' for details.

CAUTION: To maintain the integrity of the system, we strongly recommend that changes in the SAC and port monitor administrative files be made with sacadm and pmadm, and not by editing the files directly. The SAC daemon does not recognize changes in some of the fields in these files unless they are made using the appropriate administrative command. Editing the file directly can lead to unexpected results.

Each line in the port monitor administrative file contains five fields delimited by colons in the following format:


These fields have the following meanings:

A unique tag that identifies a service. This tag is unique only for the port monitor through which the service is available. Other port monitors may offer the same or other services with the same tag. A service requires both a port monitor tag and a service tag to identify it uniquely.

svctag may consist of up to 14 alphanumeric characters.

Flags with the following meanings may currently be included in this field:

Do not enable this port. By default the port is enabled.

Create an entry for this service in /var/adm/utmp. By default no utmp entry is created for the service.

The utmp file is used by the who(1) command, which reports a list of users currently logged in, and the ports on which they are working. Note that port monitors may ignore the ``u'' flag if creating a utmp entry for the service is not appropriate to the manner in which the service is to be invoked. Some services may not start properly unless utmp entries have been created for them. For example, services using the login scheme require a utmp entry.

The identity under which the service is to be started. The identity has the form of a login name as it appears in /etc/passwd. If this field is empty, the identity is supplied by the authentication scheme. When an ID and an authentication scheme are both specified, the port monitor performs the authentication under the scheme-supplied identity and invokes the service under the identity specified in the ID field. If neither ID nor authentication scheme is supplied, an error is returned when the service is executed.

The authentication scheme for the service. If the scheme field is empty, no authentication is done by the port monitor.

Examples of port monitor-specific information are addresses, the name of a process to execute, or the name of a STREAMS pipe to pass a connection through.
An optional comment, beginning with a hash sign (#), may be present at the end of each line in the file.
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 22 April 2004