The file consists of a series of single-line entries, each entry corresponding to a service to be invoked by inetd. These services are connection-based, datagram, or ``internal.''
Internal services are those supported by the inetd program: these services are echo, discard, chargen (character generator), daytime (human readable time), and time (machine readable time, in the form of the number of seconds since midnight, January 1, 1900). All of these services are both TCP and UDP based. (For details of these services, consult the appropriate RFC from the Network Information Center: RFC 862, RFC 863, RFC 864, RFC 867, RFC 868, respectively.)
There are two types of services that inetd can start: standard and TCPMUX. A standard service has a well-known port assigned to it; it may be a service that implements an official Internet standard or it may be a UNIX-specific service. As described in RFC 1078, TCPMUX services are non-standard services that do not have a well-known port assigned to them. They are invoked from inetd when a program connects to the ``tcpmux'' well-known port and specifies the service name. This feature is useful for adding locally-developed servers.
For TCPMUX services, the value of the ``service-name'' field consists of the string tcpmux followed by a slash and the locally-chosen service name. The service names listed in /etc/services and the name ``help'' are reserved. Try to choose unique names for your TCPMUX services by prefixing them with your organization's name and suffixing them with a version number.
NOTE: If TCPMUX services are to be specified in this file, an entry with the service name ``tcpmux'' must exist in this file to turn on the TCPMUX service in the inetd server. See line 8 in the ``Example'' section. This line is in /etc/inetd.conf by default.
Each service, excluding TCPMUX services but including internal services and the ``tcpmux'' service by itself, must have a valid entry in /etc/services. In the case of an internal service, its name must correspond to the official name of the service: that is, the first field of the service entry in /etc/services. The entry for the ``tcpmux'' service itself is in /etc/services by default.
Each entry has a series of space- or tab-separated fields. (No field, except for the last one, may be omitted.) The fields are as follows:
The distribution inetd.conf file contains
prototype entries; refer to these entries when editing the
. . . ftp stream tcp nowait NOLUID /etc/ftpd ftpd telnet stream tcp nowait NOLUID /etc/telnetd telnetd login stream tcp nowait NOLUID /etc/rlogind rlogind exec stream tcp nowait NOLUID /etc/rexecd rexecd finger stream tcp nowait nouser /etc/fingerd fingerd tcpmux/+date stream tcp nowait sync /bin/date tcpmux/phone stream tcp nowait sync /usr/local/bin/pbook pbook tcpmux stream tcp nowait root internal echo stream tcp nowait root internal discard stream tcp nowait root internal chargen stream tcp nowait root internal daytime stream tcp nowait root internal time stream tcp nowait root internal echo dgram udp wait root internal discard dgram udp wait root internal chargen dgram udp wait root internal daytime dgram udp wait root internal time dgram udp wait root internal . . .