The /etc/services file associates Internet service names and aliases with the port number and protocol used by the service. Each service is listed in this file on a single line of the form: ServiceName PortNumber/ProtocolName Aliases
The fields contain the following information: The official Internet service name. The socket port number used for the service and the transport protocol used for the service. A list of unofficial service names.
Items on a line are separated by spaces or tabs. Comments begin with a # (number sign) and continue to the end of the line.
Entries in the /etc/services file for the inetd internal services might look like this: echo 7/tcp echo 7/udp discard 9/tcp sink null discard 9/udp sink null daytime 13/tcp daytime 13/udp chargen 19/tcp ttytst source chargen 19/tcp ttytst source ftp 21/tcp time 37/tcp timeserver time 37/udp timeserver
Functions: endservent(3), getservbyname(3), getservbyport(3), getservent(3), setservent(3)
The RFC923 specification. delim off