SERVICES(5) File Formats Manual SERVICES(5)

services
service name data base

The services file contains information regarding the known services available in the DARPA Internet. For each service a single line should be present with the following information:
official service name
port number
protocol name
aliases

Items are separated by any number of blanks and/or tab characters. The port number and protocol name are considered a single item; a slash (“/”) is used to separate the port and protocol (e.g. “512/tcp”). A hash (“#”) indicates the beginning of a comment; subsequent characters up to the end of the line are not interpreted by the routines which search the file.

Service names may contain any printable character other than a field delimiter, newline, or comment character.

The database in /var/db/services.db needs to be updated with services_mkdb(8) after changes to the services file have been applied.

/etc/services
The services file resides in /etc.

getservent(3), services_mkdb(8)

The services file format appeared in 4.2BSD.

A name server should be used instead of a static file.
June 19, 2007 NetBSD 9.4