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 ypdomainname - show or set the system's NIS/YP domain name
9 nisdomainname - show or set the system's NIS/YP domain name
10 dnsdomainname - show the system's DNS 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] [-b] [--boot] [-F filename] [--file filename] [hostname]
18 hostname [-v] [-h] [--help] [-V] [--version]
19 domainname [nisdomain] [-F file]
21 ypdomainname [nisdomain] [-F file]
22 nisdomainname [nisdomain] [-F file]
23 dnsdomainname [-v]
25
28 Hostname is used to display the system's DNS name, and to display or
29 set its hostname or NIS domain name.
30 GET NAME
33 When called without any arguments, the program displays the current
34 names:
35 hostname will print the name of the system as returned by the gethost‐
37 name(2) function.
38 domainname will print the NIS domainname of the system. domainname
40 uses the gethostname(2) function, while ypdomainname and nisdomainname
41 use the yp_get_default_domain(3).
42 dnsdomainname will print the domain part of the FQDN (Fully Qualified
44 Domain Name). The complete FQDN of the system is returned with hostname
45 --fqdn (but see the warnings in section THE FQDN below).
46 The function gethostname(2) is used to get the hostname. When the
49 hostname -a, -d, -f or -i is called will gethostbyname(3) be called.
50 The difference in gethostname(2) and gethostbyname(3) is that gethost‐
51 byname(3) is network aware, so it consults /etc/nsswitch.conf and
52 /etc/host.conf to decide whether to read information in /etc/syscon‐
53 fig/network or /etc/hosts
54 To add another dimension to this, the hostname is also set when the
56 network interface is brought up.
57 SET NAME
60 When called with one argument or with the --file option, the commands
61 set the host name or the NIS/YP domain name. hostname uses the
62 sethostname(2) function, while all of the three domainname, ypdomain‐
63 name and nisdomainname use setdomainname(2). Note, that this is effec‐
64 tive only until the next reboot. After reboot original names from
65 /etc/hosts are used again.
66 Note, that only the super-user can change the names.
68 It is not possible to set the FQDN or the DNS domain name with the dns‐
70 domainname command (see THE FQDN below).
71 The host name is usually set once at system startup in
73 /etc/rc.d/rc.sysinit (normally by reading the contents of a file which
74 contains the host name, e.g. /etc/sysconfig/network).
75 THE FQDN
78 You can't change the FQDN (as returned by hostname --fqdn) or the DNS
79 domain name (as returned by dnsdomainname) with this command. The FQDN
80 of the system is the name that the resolver(3) returns for the host
81 name.
82 Technically: The FQDN is the name getaddrinfo(3) returns for the host
84 name returned by gethostname(2). The DNS domain name is the part after
85 the first dot.
86 Therefore it depends on the configuration (usually in /etc/host.conf)
88 how you can change it. Usually (if the hosts file is parsed before DNS
89 or NIS) you can change it in /etc/hosts.
90 If a machine has multiple network interfaces/addresses or is used in a
92 mobile environment, then it may either have multiple FQDNs/domain names
93 or none at all. Therefore avoid using hostname --fqdn, hostname
94 --domain and dnsdomainname. hostname --ip-address is subject to the
95 same limitations so it should be avoided as well.
96
99 -a, --alias
100 Display the alias name of the host (if used). This option is
101 deprecated and should not be used anymore.
102 -b, --boot
104 Always set a hostname; this allows the file specified by -F to
105 be non-existant or empty, in which case the default hostname
106 localhost will be used if none is yet set.
107 -d, --domain
109 Display the name of the DNS domain. Don't use the command
110 domainname to get the DNS domain name because it will show the
111 NIS domain name and not the DNS domain name. Use dnsdomainname
112 instead. Ssee the warnings in section THE FQDN above, and avoid
113 using this option.
114 -F, --file filename
116 Read the host name from the specified file. Comments (lines
117 starting with a `#') are ignored.
118 -f, --fqdn, --long
120 Display the FQDN (Fully Qualified Domain Name). A FQDN consists
121 of a short host name and the DNS domain name. Unless you are
122 using bind or NIS for host lookups you can change the FQDN and
123 the DNS domain name (which is part of the FQDN) in the
124 /etc/hosts file. See the warnings in section THE FQDN above, and
125 avoid using this option; use hostname --all-fqdns instead.
126 -A, --all-fqdns
128 Displays all FQDNs of the machine. This option enumerates all
129 configured network addresses on all configured network inter‐
130 faces, and translates them to DNS domain names. Addresses that
131 cannot be translated (i.e. because they do not have an appropri‐
132 ate reverse DNS entry) are skipped. Note that different
133 addresses may resolve to the same name, therefore the output may
134 contain duplicate entries. Do not make any assumptions about the
135 order of the output.
136 -h, --help
138 Print a usage message and exit.
139 -i, --ip-address
141 Display the network address(es) of the host name. Note that this
142 works only if the host name can be resolved. Avoid using this
143 option; use hostname --all-ip-addresses instead.
144 -I, --all-ip-addresses
146 Display all network addresses of the host. This option enumer‐
147 ates all configured addresses on all network interfaces. The
148 loopback interface and IPv6 link-local addresses are omitted.
149 Contrary to option -i, this option does not depend on name reso‐
150 lution. Do not make any assumptions about the order of the out‐
151 put.
152 -s, --short
154 Display the short host name. This is the host name cut at the
155 first dot.
156 -V, --version
158 Print version information on standard output and exit success‐
159 fully.
160 -v, --verbose
162 Verbose output was removed.
163 -y, --yp, --nis
165 Display the NIS domain name. If a parameter is given (or --file
166 name ) then root can also set a new NIS domain.
167
169 The address families hostname tries when looking up the FQDN, aliases
170 and network addresses of the host are determined by the configuration
171 of your resolver. For instance, on GNU Libc systems, the resolver can
172 be instructed to try IPv6 lookups first by using the inet6 option in
173 /etc/resolv.conf.
174
176 /etc/hosts
177 /etc/sysconfig/network
179
181 Peter Tobias, <tobias@et-inf.fho-emden.de>
182 Bernd Eckenfels, <net-tools@lina.inka.de> (NIS and manpage).
183 Michael Meskes, <meskes@debian.org>
184net-tools 2009-09-16 HOSTNAME(1)