The
hosts
file contains information regarding
the known hosts on the network.
It can be used in conjunction with DNS, and the NIS
maps `hosts.byaddr' and `hosts.byname', as controlled by
nsswitch.conf(5).
For each host a single line should be present
with the following information:
Internet address
official host name
aliases
Items are separated by any number of blanks and/or
tab characters.
A ``#'' indicates the beginning of
a comment; characters up to the end of the line are
not interpreted by routines which search the file.
This file provides a backup used when the name server
is not running.
For the name server, it is suggested that only a few addresses
be included in this file.
These include addresses for the local interfaces that
ifconfig(8)
needs at boot time and a few machines on the local network.
Network addresses are specified in either the conventional
``.'' (dot) notation for IPv4 or colon hexadecimal notation for IPv6,
as understood by the
inet_pton(3)
routine
from the Internet address manipulation library,
inet(3).
Host names may contain any printable
character other than a field delimiter, newline,
or comment character.
