1HOSTNAME(1) Linux Programmer's Manual HOSTNAME(1)
2
6 hostname - show or set the system's host name
7 domainname - show or set the system's NIS/YP domain name
8 dnsdomainname - show the system's DNS domain name
9 nisdomainname - show or set system's NIS/YP domain name
10 ypdomainname - show or set the system's NIS/YP domain name
11
14 hostname [-v] [-a] [--alias] [-d] [--domain] [-f] [--fqdn] [-A] [--all-
15 fqdns] [-i] [--ip-address] [-I] [--all-ip-addresses] [--long] [-s]
16 [--short] [-y] [--yp] [--nis]
17 hostname [-v] [-F filename] [--file filename] [hostname]
20 domainname [-v] [-F filename] [--file filename] [name]
23 nodename [-v] [-F filename] [--file filename] [name]
26 hostname [-v] [-h] [--help] [-V] [--version]
29 dnsdomainname [-v]
32 nisdomainname [-v]
33 ypdomainname [-v]
34
37 Hostname is the program that is used to either set or display the cur‐
38 rent host, domain or node name of the system. These names are used by
39 many of the networking programs to identify the machine. The domain
40 name is also used by NIS/YP.
41 GET NAME
44 When called without any arguments, the program displays the current
45 names:
46 hostname will print the name of the system as returned by the gethost‐
49 name(2) function.
50 domainname, nisdomainname, ypdomainname will print the name of the sys‐
53 tem as returned by the getdomainname(2) function. This is also known as
54 the YP/NIS domain name of the system.
55 dnsdomainname will print the domain part of the FQDN (Fully Qualified
58 Domain Name). The complete FQDN of the system is returned with hostname
59 --fqdn.
60 The function gethostname(2) is used to get the hostname. When the
63 hostname -a, -d, -f or -i is called will gethostbyname(3) be called.
64 The difference in gethostname(2) and gethostbyname(3) is that gethost‐
65 byname(3) is network aware, so it consults /etc/nsswitch.conf and
66 /etc/host.conf to decide whether to read information in /etc/syscon‐
67 fig/network or /etc/hosts
68 To add another dimension to this, the hostname is also set when the
70 network interface is brought up.
71 SET NAME
74 When called with one argument or with the --file option, the commands
75 set the host name, the NIS/YP domain name or the node name.
76 Note, that only the super-user can change the names.
79 It is not possible to set the FQDN or the DNS domain name with the dns‐
82 domainname command (see THE FQDN below).
83 The host name is usually set once at system startup in
86 /etc/rc.d/rc.inet1 or /etc/init.d/boot (normally by reading the con‐
87 tents of a file which contains the host name, e.g. /etc/hostname).
88 THE FQDN
91 You can't change the FQDN (as returned by hostname --fqdn) or the DNS
92 domain name (as returned by dnsdomainname) with this command. The FQDN
93 of the system is the name that the resolver(3) returns for the host
94 name.
95 Technically: The FQDN is the name gethostbyname(2) returns for the host
98 name returned by gethostname(2). The DNS domain name is the part after
99 the first dot.
100 Therefore it depends on the configuration (usually in /etc/host.conf)
102 how you can change it. Usually (if the hosts file is parsed before DNS
103 or NIS) you can change it in /etc/hosts.
104 If a machine has multiple network interfaces/addresses or is used in a
106 mobile environment, then it may either have multiple FQDNs/domain names
107 or none at all. Therefore avoid using hostname --fqdn, hostname
108 --domain and dnsdomainname. hostname --ip-address is subject to the
109 same limitations so it should be avoided as well.
110
113 -a, --alias
114 Display the alias name of the host (if used).
115 -d, --domain
117 Display the name of the DNS domain. Don't use the command
118 domainname to get the DNS domain name because it will show the
119 NIS domain name and not the DNS domain name. Use dnsdomainname
120 instead.
121 -F, --file filename
123 Read the host name from the specified file. Comments (lines
124 starting with a `#') are ignored.
125 -f, --fqdn, --long
127 Display the FQDN (Fully Qualified Domain Name). A FQDN consists
128 of a short host name and the DNS domain name. Unless you are
129 using bind or NIS for host lookups you can change the FQDN and
130 the DNS domain name (which is part of the FQDN) in the
131 /etc/hosts file. See the warnings in section THE FQDN above, and
132 avoid using this option; use hostname --all-fqdns instead.
133 -A, --all-fqdns
135 Displays all FQDNs of the machine. This option enumerates all
136 configured network addresses on all configured network inter‐
137 faces, and translates them to DNS domain names. Addresses that
138 cannot be translated (i.e. because they do not have an appropri‐
139 ate reverse DNS entry) are skipped. Note that different
140 addresses may resolve to the same name, therefore the output may
141 contain duplicate entries. Do not make any assumptions about the
142 order of the output.
143 -h, --help
145 Print a usage message and exit.
146 -i, --ip-address
148 Display the IP address(es) of the host. Note that this works
149 only if the host name can be resolved. Avoid using this option;
150 use hostname --all-ip-addresses instead.
151 -I, --all-ip-addresses
153 Display all network addresses of the host. This option enumer‐
154 ates all configured addresses on all network interfaces. The
155 loopback interface and IPv6 link-local addresses are omitted.
156 Contrary to option -i, this option does not depend on name reso‐
157 lution. Do not make any assumptions about the order of the out‐
158 put.
159 -s, --short
161 Display the short host name. This is the host name cut at the
162 first dot.
163 -V, --version
165 Print version information on standard output and exit success‐
166 fully.
167 -v, --verbose
169 Be verbose and tell what's going on.
170 -y, --yp, --nis
172 Display the NIS domain name. If a parameter is given (or --file
173 name ) then root can also set a new NIS domain.
174
176 /etc/hosts /etc/sysconfig/network
177
179 Note that hostname doesn't change anything permanently. After reboot
180 original names from /etc/hosts are used again.
181
183 Peter Tobias, <tobias@et-inf.fho-emden.de>
184 Bernd Eckenfels, <net-tools@lina.inka.de> (NIS and manpage).
185 Steve Whitehouse, <SteveW@ACM.org> (DECnet support and manpage).
186net-tools 28 Jan 1996 HOSTNAME(1)