Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files. =================================================================== RCS file: /ftp/cvs/cvsroot/src/share/man/man7/hostname.7,v retrieving revision 1.10 retrieving revision 1.11 diff -u -p -r1.10 -r1.11 --- src/share/man/man7/hostname.7 2010/09/29 13:44:33 1.10 +++ src/share/man/man7/hostname.7 2010/09/29 14:34:07 1.11 @@ -1,3 +1,5 @@ +.\" $NetBSD: hostname.7,v 1.11 2010/09/29 14:34:07 wiz Exp $ +.\" .\" Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") .\" .\" Permission to use, copy, modify, and distribute this software for any @@ -31,17 +33,18 @@ .\" .Dd February 16, 1994 .Dt HOSTNAME 7 -.Os BSD 4 +.Os .Sh NAME -.Nm hostname +.Nm hostname .Nd host name resolution description .Sh DESCRIPTION -Hostnames are domains. A domain is a hierarchical, dot-separated list -of subdomains. For example, the machine -.Dq Li monet , -in the +Hostnames are domains. +A domain is a hierarchical, dot-separated list of subdomains. +For example, the machine +.Dq Li monet , +in the .Dq Li Berkeley -subdomain of the +subdomain of the .Dq Li EDU subdomain of the Internet Domain Name System would be represented as .Pp @@ -54,80 +57,85 @@ which must generally translate the name (This task is usually performed by the library routine .Xr gethostbyname 3 . ) The default method for resolving hostnames by the Internet name resolver is -to follow RFC 1535's security recommendations. Actions can be taken -by the administrator to override these recommendations and to have the -resolver behave the same as earlier, non-RFC 1535 -resolvers. +to follow RFC 1535's security recommendations. +Actions can be taken by the administrator to override these +recommendations and to have the resolver behave the same as earlier, +non-RFC 1535 resolvers. .Pp The default method (using RFC 1535 guidelines) follows: .Pp If the name consists of a single component, i.e. contains no dot, and if the -environment variable -.Dq Ev HOSTALIASES +environment variable +.Dq Ev HOSTALIASES is set to the name of a file, -that file is searched for a string matching the input hostname. The file +that file is searched for a string matching the input hostname. +The file should consist of lines made up of two strings separated by white-space, the first of which is the hostname alias, and the second of which is the complete -hostname to be substituted for that alias. If a case-insensitive match is +hostname to be substituted for that alias. +If a case-insensitive match is found between the hostname to be resolved and the first field of a line in the file, the substituted name is looked up with no further processing. .Pp -If there is at least one dot in the name, then the name is first tried -.Dq as-is . +If there is at least one dot in the name, then the name is first tried +.Dq as-is . The number of dots to cause this action is configurable by setting the -threshold using the +threshold using the .Dq Li ndots -option in +option in .Pa /etc/resolv.conf -(default: 1). If the name ends with a dot, the trailing dot is +(default: 1). +If the name ends with a dot, the trailing dot is removed, and the remaining name is looked up (regardless of the setting of -the -.Li ndots -option), without further processing. +the +.Li ndots +option), without further processing. .Pp If the input name does not end with a trailing dot, it is looked up by -searching through a list of domains until a match is found. If neither the -search option in the +searching through a list of domains until a match is found. +If neither the search option in the .Pa /etc/resolv.conf -file or the -.Dq Ev LOCALDOMAIN +file or the +.Dq Ev LOCALDOMAIN environment variable is used, then the -search list of domains contains only the full domain specified by the +search list of domains contains only the full domain specified by the .Li domain option (in .Pa /etc/resolv.conf ) -or the domain used in the local hostname. For example, if the -.Dq Li domain -option is set to +or the domain used in the local hostname. +For example, if the +.Dq Li domain +option is set to .Li CS.Berkeley.EDU , -then only -.Li CS.Berkeley.EDU +then only +.Li CS.Berkeley.EDU will be in the search list, and this will be the only -domain appended to the partial hostname. For example, if -.Dq Li lithium +domain appended to the partial hostname. +For example, if +.Dq Li lithium is the name to be resolved, this would make -.Li lithium.CS.Berkeley.EDU +.Li lithium.CS.Berkeley.EDU the only name to be tried using the search list. .Pp -If the -.Li search +If the +.Li search option is used in .Pa /etc/resolv.conf -or the environment variable -.Dq Ev LOCALDOMAIN +or the environment variable +.Dq Ev LOCALDOMAIN is set by the user, then -the search list will include what is set by these methods. For -example, if the -.Dq Li search +the search list will include what is set by these methods. +For example, if the +.Dq Li search option contained .Pp .Dl CS.Berkeley.EDU CChem.Berkeley.EDU Berkeley.EDU .Pp -then the partial hostname (e.g., -.Dq Li lithium ) -will be tried with +then the partial hostname (e.g., +.Dq Li lithium ) +will be tried with .Em each -domain name appended (in the same order specified); the resulting hostnames +domain name appended (in the same order specified); the resulting hostnames that would be tried are: .Bd -literal -offset indent lithium.CS.Berkeley.EDU @@ -135,30 +143,30 @@ lithium.CChem.Berkeley.EDU lithium.Berkeley.EDU .Ed .Pp -The environment variable -.Dq Ev LOCALDOMAIN +The environment variable +.Dq Ev LOCALDOMAIN overrides the -.Dq Li search -and -.Dq Li domain -options, and if both -.Li search -and +.Dq Li search +and +.Dq Li domain +options, and if both +.Li search +and .Li domain -options are present in the resolver configuration file, then only the +options are present in the resolver configuration file, then only the .Em last one listed is used (see .Xr resolver 5 ) . .Pp -If the name was not previously tried -.Dq as-is +If the name was not previously tried +.Dq as-is (i.e., it fell below the -.Dq Li ndots +.Dq Li ndots threshold or did not contain a dot), then the name as originally provided is attempted. .Sh ENVIRONMENT .Bl -tag -width "/etc/resolv.conf " -.It Ev LOCALDOMAIN +.It Ev LOCALDOMAIN Affects domains appended to partial hostnames. .It Ev HOSTALIASES Name of file containing @@ -169,9 +177,9 @@ pairs. .Bl -tag -width "/etc/resolv.conf " -compact .It Pa /etc/resolv.conf See -.Xr resolve 5 . +.Xr resolver 5 . .El .Sh SEE ALSO .Xr gethostbyname 3 , .Xr resolver 5 , -.Xr mailaddr 7 , +.Xr mailaddr 7