`inetd`

Internet super-server

Syntax:

inetd [-d] [configuration_file]

Options:

-d: Turn on debugging.
configuration_file: Read the configuration information from this file. If this file isn't specified, the configuration information is read from /etc/inetd.conf.

The inetd daemon, which is typically started by /etc/netstart, listens for connections on certain well-known ports. When it finds a connection on one of its sockets, the daemon decides what service the socket corresponds to, and invokes a program to service the request. After that program is finished, inetd continues to listen on the socket (except in some cases, which are described below). Essentially, inetd lets you run one daemon to invoke several others, reducing load on the system.

When it starts, inetd reads its configuration information from a configuration file; by default, this is /etc/inetd.conf. The file must have an entry in each of its fields, with each field separated by a tab or a space. Comments are denoted by a pound sign (#) at the beginning of a line.

Internal services

The inetd daemon provides several ``trivial'' services internally by using routines within itself. These services are:

echo: (echoes data received)
discard: (discards data received)
chargen: (generates characters)
daytime: (human-readable time)
time: (machine-readable time, in the form of the number of seconds since midnight, January 1, 1900)

All of these services are UDP- or TCP-based.

Effects of SIGHUP

When it receives SIGHUP, inetd rereads its configuration file, which may cause services to be added, deleted, or modified.

Files:

/etc/inetd.conf: Super-server configuration file.