host Command

Purpose

Resolves a host name into an Internet address or an Internet address into a host name.

Syntax

host [-n [ -a ] [ -c Class ] [ -d ] [ -r ] [ -t Type ] [ -v ] [ -w ]] Hostname | Address [ Server ]

hostnew [ -a ] [ -c Class ] [ -d ] [ -r ] [ -t Type ] [ -v ] [ -w ] Hostname | Address [ Server ]

Description

The /usr/bin/host command returns the Internet address of a host machine when the HostName parameter is specified and the name of the host when the Address parameter is specified. Depending on the configuration of name resolution service, the host command may also display any aliases associated with the HostName parameter. Examples of name resolution services include local, nis, and bind.

If the local host is using the Domain Name Protocol, the local or remote name server database is queried before searching the local /etc/hosts file.

Flags

Item Description
-a Equivalent to using "-v -t *"
-c Class Specifies the class to look in when searching non-Internet data. Valid classes are:
IN
Internet class
CHAOS
Chaos class
HESIOD
MIT Althena Hesiod class
ANY
Wildcard (any of the above)
-d Turns on debugging mode.
-n Equivalent to issuing the /usr/bin/hostnew command. The hostnew command is the 5.2 version of the host command. The hostnew command performs bind resolution service.
-r Disables recursive processing.
-t Type Specifies the type of record to query for. Valid types are:
A
Host's Internet address
CNAME
Canonical name for an alias
HINFO
Host CPU and operating system type
KEY
Security Key Record
MINFO
Mailbox or mail list information
MX
Mail exchanger
NS
Nameserver for the named zone
PTR
Host name if the query is an Internet address; otherwise, the pointer to other information
SIG
Signature Record
SOA
Domain's "start-of-authority" information
TXT
Text information
UINFO
User information
WKS
Supported well-known services
-v Verbose mode.
-w Waits forever for a reply from the DNS server.

Parameters

Item Description
Address Specifies the Internet address of the host machine to use in resolving the host name. The Address parameter must be a valid Internet address in dotted decimal format.
HostName Specifies the name of the host machine to use in resolving the Internet address. The HostName parameter can be either a unique host name or a well-known host name (such as nameserver, printserver, or timeserver, if these exist).
Server Specifies the nameserver to query.

Examples

  1. To display the address of a host machine named mephisto, enter: 
    host mephisto
    Information similar to the following is displayed: 
    mephisto is 192.100.13.5, Aliases: engr, sarah
  2. To display the host whose address is 192.100.13.1, enter: 
    host 192.100.13.1
    Information similar to the following is displayed: 
    mercutio is 192.100.13.1
  3. To display the MX records for the domain named test.ibm.com, enter: 
    host -n -t mx test.ibm.com
    or 
    hostnew -t mx test.ibm.com
    Information similar to the following is displayed: 
    test.ibm.com mail is handled (pri=10) by test1.tt.ibm.com
test.ibm.com mail is handled (pri=10) by test2.aix.ibm.com

Files

Item Description
/etc/hosts Contains the Internet Protocol (IP) name and addresses of hosts on the local network.