hosts - host name database
The hosts file contains information regarding the known
hosts on the network.
For each host, a single line should be present with
Official host name
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.
The system configuration file resolv.conf(5) controls where
host name information
will be searched for. The mechanism provided permits the administrator
to describe the databases to search; the
known include yp(8), DNS and the hosts database.
When using the name server named(8), this file provides a
backup 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.
This file may be created from the official host database
the Network Information Control Center (NIC), though local
changes may be
required to bring it up to date regarding unofficial aliases
hosts. As the database maintained at NIC is incomplete, use of the
name server is recommended for sites on the DARPA Internet.
Network addresses are specified in the conventional Internet
notation using the inet_addr(3) routine from the Internet
library, inet(3). Host names may contain any printable character
other than a field delimiter, newline, or comment character.
getaddrinfo(3), gethostbyname(3), getnameinfo(3), resolv.conf(5),
Name Server Operations Guide for BIND.
The hosts file format appeared in 4.2BSD.
A name server should be used instead of a static file.
Lines in /etc/hosts are limited to BUFSIZ characters (currently 1024).
Longer lines will be ignored.
OpenBSD 3.6 December 11, 1993
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