The services file contains the assignment of services and protocols to port numbers.
The services file is known from the Unix/LINUX world as /etc/services. With the help of this file an application can determine the server port for a service under a particular protocol. Consequently the application does not need to be assigned a permanent port for a required service when generation takes place. In addition, it is possible to offer a service which is generally known locally on a port other than the default port.
Previously a static services table with the "well-known" port numbers from1-1023 was contained in SOCKETS(BS2000). It was not possible to extend or modify this table. The external table enables assignments to be specified over the entire port number range from 1-65535.
In the delivery status the services file is predefined under BCAM administration with the services currently registered by IANA in the port number range 1-1023.
Instead of an internal table, SOCKETS(BS2000) uses the services file managed by BCAM.
Name and content of the services file
The name of the services file is defined using the SERVICES-TABLE parameter in the DCOPT, DCSTART und BCMOD commands.
(Default name: $TSOS.SYSDAT.BCAM.ETC.SERVICES).
The following syntax rules apply for the file entries:
Comment lines:
1st character = * or #
Format of all other lines (from left to right):
Entry in the case of function 1:
service-name
At least 1 blank
port-number
separated by /
protocol
At least 1 blank
Optionally up to 4 further (secondary) service-names
(separated by at least 1 blank)
From # the rest of the line is interpreted as a comment.
Example
Examples can be found in the services file supplied.