services File Format for TCP/IP
Purpose
Defines the sockets and protocols used for Internet services.
Description
The /etc/services file contains information about the known services used in the DARPA Internet network. Each service is listed on a single line corresponding to the form:
ServiceName PortNumber/ProtocolName Aliases
These fields contain the following information:
| Item | Description |
|---|---|
| ServiceName | Specifies an official Internet service name. |
| PortNumber | Specifies the socket port number used for the service. |
| ProtocolName | Specifies the transport protocol used for the service. |
| Aliases | Specifies a list of unofficial service names. |
Items on a line are separated by spaces or tabs. Comments begin with a # (pound sign) and continue until the end of the line.
The service and alias names are case sensitive.
If you edit the /etc/services file, run the refresh -s inetd or kill -1 InetdPID command to inform the inetd daemon of the changes.
Examples
Entries in the services file for the inetd internal services may 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/udp ttytst source
ftp 21/tcp
time 37/tcp timeserver
time 37/udp timeserver