1、Ubuntu 20.04查看主机名的几种方法如下。
root@hanyw1618-9999:~# hostnamehanyw1618-9999root@hanyw1618-9999:~# uname -aLinux hanyw1618-9999 5.15.0-33-generic #34-Ubuntu SMP Wed May 18 13:34:26 UTC 2022 x86_64 x86_64 x86_64 GNU/Linuxroot@hanyw1618-9999:~# cat /etc/hosts127.0.0.1 localhost127.0.1.1 hanyw hanyw666127.0.0.1 hanyw-ubuntu ubuntu.demo01.hanyw.com bj.ubuntu01.hanyw.com test01.hanyw.com# The following lines are desirable for IPv6 capable hosts::1 ip6-localhost ip6-loopbackfe00::0 ip6-localnetff00::0 ip6-mcastprefixff02::1 ip6-allnodesff02::2 ip6-allroutersroot@hanyw1618-9999:~# uname -nhanyw1618-9999
2、hostname的man帮助手册如下。
HOSTNAME(1) Linux Programmer's Manual HOSTNAME(1)NAMEhostname - show or set the system's host namedomainname - show or set the system's NIS/YP domain nameypdomainname - show or set the system's NIS/YP domain namenisdomainname - show or set the system's NIS/YP domain namednsdomainname - show the system's DNS domain nameSYNOPSIShostname [-a|--alias] [-d|--domain] [-f|--fqdn|--long] [-A|--all-fqdns] [-i|--ip-address] [-I|--all-ip-ad‐dresses] [-s|--short] [-y|--yp|--nis]hostname [-b|--boot] [-F|--file filename] [hostname]hostname [-h|--help] [-V|--version]domainname [nisdomain] [-F file]ypdomainname [nisdomain] [-F file]nisdomainname [nisdomain] [-F file]dnsdomainnameDESCRIPTIONHostname is used to display the system's DNS name, and to display or set its hostname or NIS domain name.GET NAMEWhen called without any arguments, the program displays the current names:hostname will print the name of the system as returned by the gethostname(2) function.domainname will print the NIS domainname of the system. domainname uses the gethostname(2) function, while yp‐domainname and nisdomainname use the getdomainname(2).dnsdomainname will print the domain part of the FQDN (Fully Qualified Domain Name). The complete FQDN of thesystem is returned with hostname --fqdn (but see the warnings in section THE FQDN below).SET NAMEWhen called with one argument or with the --file option, the commands set the host name or the NIS/YP domainname. hostname uses the sethostname(2) function, while all of the three domainname, ypdomainname and nisdo‐mainname use setdomainname(2). Note, that this is effective only until the next reboot. Edit /etc/hostnamefor permanent change.Note, that only the super-user can change the names.It is not possible to set the FQDN or the DNS domain name with the dnsdomainname command (see THE FQDN below).The host name is usually set once at system startup in /etc/init.d/hostname.sh (normally by reading the con‐tents of a file which contains the host name, e.g. /etc/hostname).THE FQDNThe FQDN (Fully Qualified Domain Name) of the system is the name that the resolver(3) returns for the hostname, such as, ursula.example.com. It is usually the hostname followed by the DNS domain name (the part afterthe first dot). You can check the FQDN using hostname --fqdn or the domain name using dnsdomainname.You cannot change the FQDN with hostname or dnsdomainname.The recommended method of setting the FQDN is to make the hostname be an alias for the fully qualified name us‐ing /etc/hosts, DNS, or NIS. For example, if the hostname was "ursula", one might have a line in /etc/hostswhich reads127.0.1.1 ursula.example.com ursulaTechnically: The FQDN is the name getaddrinfo(3) returns for the host name returned by gethostname(2). The DNSdomain name is the part after the first dot.Therefore it depends on the configuration of the resolver (usually in /etc/host.conf) how you can change it.Usually the hosts file is parsed before DNS or NIS, so it is most common to change the FQDN in /etc/hosts.If a machine has multiple network interfaces/addresses or is used in a mobile environment, then it may eitherhave multiple FQDNs/domain names or none at all. Therefore avoid using hostname --fqdn, hostname --domain anddnsdomainname. hostname --ip-address is subject to the same limitations so it should be avoided as well.OPTIONS-a, --aliasDisplay the alias name of the host (if used). This option is deprecated and should not be used anymore.-A, --all-fqdnsDisplays all FQDNs of the machine. This option enumerates all configured network addresses on all con‐figured network interfaces, and translates them to DNS domain names. Addresses that cannot be translated(i.e. because they do not have an appropriate reverse IP entry) are skipped. Note that different ad‐dresses may resolve to the same name, therefore the output may contain duplicate entries. Do not makeany assumptions about the order of the output.-b, --bootAlways set a hostname; this allows the file specified by -F to be non-existent or empty, in which casethe default hostname localhost will be used if none is yet set.-d, --domainDisplay the name of the DNS domain. Don't use the command domainname to get the DNS domain name becauseit will show the NIS domain name and not the DNS domain name. Use dnsdomainname instead. See the warn‐ings in section THE FQDN above, and avoid using this option.-f, --fqdn, --longDisplay the FQDN (Fully Qualified Domain Name). A FQDN consists of a short host name and the DNS domainname. Unless you are using bind or NIS for host lookups you can change the FQDN and the DNS domain name(which is part of the FQDN) in the /etc/hosts file. See the warnings in section THE FQDN above und usehostname --all-fqdns instead wherever possible.-F, --file filenameRead the host name from the specified file. Comments (lines starting with a `#') are ignored.-i, --ip-addressDisplay the network address(es) of the host name. Note that this works only if the host name can be re‐solved. Avoid using this option; use hostname --all-ip-addresses instead.-I, --all-ip-addressesDisplay all network addresses of the host. This option enumerates all configured addresses on all net‐work interfaces. The loopback interface and IPv6 link-local addresses are omitted. Contrary to option-i, this option does not depend on name resolution. Do not make any assumptions about the order of theoutput.-s, --shortDisplay the short host name. This is the host name cut at the first dot.-V, --versionPrint version information on standard output and exit successfully.-y, --yp, --nisDisplay the NIS domain name. If a parameter is given (or --file name ) then root can also set a new NISdomain.-h, --helpPrint a usage message and exit.NOTESThe address families hostname tries when looking up the FQDN, aliases and network addresses of the host are de‐termined by the configuration of your resolver. For instance, on GNU Libc systems, the resolver can be in‐structed to try IPv6 lookups first by using the inet6 option in /etc/resolv.conf.FILES/etc/hostname Historically this file was supposed to only contain the hostname and not the full canonical FQDN.Nowadays most software is able to cope with a full FQDN here. This file is read at boot time by the system ini‐tialization scripts to set the hostname./etc/hosts Usually, this is where one sets the domain name by aliasing the host name to the FQDN.AUTHORSPeter Tobias, <tobias@et-inf.fho-emden.de>Bernd Eckenfels, <net-tools@lina.inka.de> (NIS and manpage).Michael Meskes, <meskes@debian.org>net-tools 2009-09-16 HOSTNAME(1)
