.\" Copyright (c) 1997 Martin Schulze (joey@infodrom.north.de)
.\" Much of the text is copied from the manpage of resolv+(8).
.\"
-.\" %%%LICENSE_START(GPLv2+_DOC_FULL)
-.\" This is free documentation; you can redistribute it and/or
-.\" modify it under the terms of the GNU General Public License as
-.\" published by the Free Software Foundation; either version 2 of
-.\" the License, or (at your option) any later version.
-.\"
-.\" The GNU General Public License's references to "object code"
-.\" and "executables" are to be interpreted as the output of any
-.\" document formatting or typesetting system, including
-.\" intermediate and printed output.
-.\"
-.\" This manual is distributed in the hope that it will be useful,
-.\" but WITHOUT ANY WARRANTY; without even the implied warranty of
-.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-.\" GNU General Public License for more details.
-.\"
-.\" You should have received a copy of the GNU General Public
-.\" License along with this manual; if not, see
-.\" <http://www.gnu.org/licenses/>.
-.\" %%%LICENSE_END
+.\" SPDX-License-Identifier: GPL-2.0-or-later
.\"
.\" 2003-08-23 Martin Schulze <joey@infodrom.org> Updated according to glibc 2.3.2
-.TH HOST.CONF 5 2015-02-21 "Linux" "Linux System Administration"
+.TH host.conf 5 (date) "Linux man-pages (unreleased)"
.SH NAME
host.conf \- resolver configuration file
.SH DESCRIPTION
.I trim
This keyword may be listed more than once.
Each time it should be
-followed by a list of domains, separated by colons (\(aq:\(aq), semicolons
-(\(aq;\(aq) or commas (\(aq,\(aq), with the leading dot.
+followed by a list of domains, separated by colons (\[aq]:\[aq]), semicolons
+(\[aq];\[aq]) or commas (\[aq],\[aq]), with the leading dot.
When set, the
-resolv+ library will automatically trim the given domain name from the
+resolver library will automatically trim the given domain name from the
end of any hostname resolved via DNS.
This is intended for use with
local hosts and domains.
-(Related note: trim will not affect hostnames
-gathered via NIS or the hosts file.
+(Related note:
+.I trim
+will not affect hostnames gathered via NIS or the
+.BR hosts (5)
+file.
Care should be taken to
ensure that the first hostname for each entry in the hosts file is
fully qualified or unqualified, as appropriate for the local
.IR on " and " off .
If set to
.IR on ,
-the resolv+ library will return all valid addresses for a host that
+the resolver library will return all valid addresses for a host that
appears in the
.I /etc/hosts
file,
.IR on " and " off .
If set to
.IR on ,
-resolv+ will attempt to reorder host addresses so that local addresses
+the resolver library
+will attempt to reorder host addresses so that local addresses
(i.e., on the same subnet) are listed first when a
.BR gethostbyname (3)
is performed.
command.
.TP
.B RESOLV_ADD_TRIM_DOMAINS
-A list of domains, separated by colons (\(aq:\(aq), semicolons (\(aq;\(aq) or
-commas (\(aq,\(aq), with the leading dot, which will be added to the list of
-domains that should be trimmed.
+A list of domains,
+separated by
+colons (\[aq]:\[aq]), semicolons (\[aq];\[aq]), or commas (\[aq],\[aq]),
+with the leading dot,
+which will be added to the list of domains that should be trimmed.
.TP
.B RESOLV_OVERRIDE_TRIM_DOMAINS
-A list of domains, separated by colons (\(aq:\(aq), semicolons (\(aq;\(aq) or
-commas (\(aq,\(aq), with the leading dot, which will replace the list of
-domains that should be trimmed.
+A list of domains,
+separated by
+colons (\[aq]:\[aq]), semicolons (\[aq];\[aq]), or commas (\[aq],\[aq]),
+with the leading dot,
+which will replace the list of domains that should be trimmed.
Overrides the
.I trim
command.
and a new environment variable
.B RESOLV_SPOOF_CHECK
can take arguments like
-.IR off ", " nowarn " and " warn .
+.IR off ", " nowarn ", and " warn .
Line comments can appear anywhere and not only at the beginning of a line.
.SS Historical
The
.BR nsswitch.conf (5)
file is the modern way of controlling the order of host lookups.
-.PP
+.P
In glibc 2.4 and earlier, the following keyword is recognized:
.TP
.I order
.IR bind ", " hosts ", and " nis .
.TP
.B RESOLV_SERV_ORDER
-Overrides the order command.
-.PP
-Since glibc 2.0.7, the following keywords and environment variable have
-been recognized but never implemented:
+Overrides the
+.I order
+command.
+.P
+.\" commit 7d68cdaa4f748e87ee921f587ee2d483db624b3d
+Since glibc 2.0.7, and up through glibc 2.24,
+the following keywords and environment variable
+have been recognized but never implemented:
.TP
.I nospoof
Valid values are
.IR on " and " off .
If set to
.IR on ,
-the resolv+ library will attempt to prevent hostname spoofing to
+the resolver library will attempt to prevent hostname spoofing to
enhance the security of
.BR rlogin " and " rsh .
-It works as follows: after performing a host address lookup, resolv+
-will perform a hostname lookup for that address.
+It works as follows: after performing a host address lookup,
+the resolver library will perform a hostname lookup for that address.
If the two hostnames
-do not match, the query will fail.
+do not match, the query fails.
The default value is
.IR off .
.TP
.I on
and the
.I nospoof
-option is also set, resolv+ will log a warning of the error via the
+option is also set,
+the resolver library will log a warning of the error via the
syslog facility.
The default value is
.IR off .
via the syslog facility.
If this option is set to
.IR warn ,
-resolv+ will attempt to prevent hostname spoofing to
+the resolver library will attempt to prevent hostname spoofing to
enhance the security and log a warning of the error via the syslog
facility.
If this option is set to
.IR nowarn ,
-the resolv+ library will attempt to prevent hostname spoofing to
+the resolver library will attempt to prevent hostname spoofing to
enhance the security but not emit warnings via the syslog facility.
Setting this option to anything else is equal to setting it to
.IR nowarn .
.TP
.B RESOLV_SPOOF_CHECK
Overrides the
-.IR nospoof ", " spoofalert, " and " spoof
+.IR nospoof ", " spoofalert ", and " spoof
commands in the same way as the
.I spoof
command is parsed.
Valid values are
-.IR off ", " nowarn, " and " warn .
+.IR off ", " nowarn ", and " warn .
.SH SEE ALSO
.BR gethostbyname (3),
.BR hosts (5),
projects / thirdparty / man-pages.git / blobdiff