Mac OS X Terminal Equivalent for Host Name Info

command linehostnameosx

In Linux, using a Bash Terminal, I can do:

hostname -d to display the name of the DNS domain, and
hostname -i to display the network address(es) of the hostname .

How can I retrieve the same information–preferably using a single command (with option, if needed), and without having to elevate privileges–from a Bash terminal in Mac OS X?

For reference, here's the Bash Version I'm using in Mac OS X:

GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin15) .

Best Answer

For the hostname -d, use hostname -f:

hostname -f | sed -e 's/^[^.]*\.//'

For IP-addresses, use ifconfig -a (look for the inet data). Your machine may have only one network device, en0, so you could do just

ifconfig en0 |awk '/inet / {print $2; }'

If you are interested in all of the network devices, keep in mind that ifconfig -l lists the devices. This lists the devices and their correspond addresses:

#!/bin/sh
for name in $(ifconfig -l)
do
    ifconfig $name |awk -v name=$name '/inet / {printf "%s: %s\n", name, $2; }'
done

Related Solutions

The difference between hostname, hostname –fqdn, and hostname -A

hostname returns the configured hostname or nodename. In practice, it can either be a short name (in most configurations) or a long name (normally the FQDN in this case). The short name is given by hostname --short.

hostname --fqdn returns the FQDN, which is gethostbyname on the nodename (as returned by the uname system call, see uname(2) man page).

hostname -A is something obscure and non-intuitive. In particular, despite its name and description ("all FQDNs"), it doesn't give the standard FQDN, by design. Thus I would say: do not use it. One reason is that it misses valid IP addresses of the machine, such as 127.0.1.1, with which the FQDN may be associated in the /etc/hosts file (this is currently the default under Debian and Ubuntu, for instance). Another issue with the hostname -A method is that the reverse resolution of an IP address doesn't necessarily give a FQDN; it can just be a short name.

Concerning your problem with python, it may be a bug there. I don't know. I suggest that you try the following Perl script:

#!/usr/bin/env perl

use strict;
use POSIX;

my $nodename = (POSIX::uname)[1];
print "Nodename: $nodename\n";

my @ghbn = gethostbyname $nodename;
print "FQDN: $ghbn[0]\n";

$ghbn[0] !~ /\./ && $ghbn[1] =~ /(\S+\.\S+)/
  and print "Fixed FQDN from aliases: $1\n";

bash – Strange Characters in GIT Completion

These strange escape sequences are color-changing commands.

The completion code runs the following command to list available commands:

git help -a|egrep '^  [a-zA-Z0-9]'

The output of git help -a looks like this:

add grep remote add--interactive hash-object remote-ext am help remote-fd … fsck-objects receive-pack write-tree gc reflog get-tar-commit-id relink

If grep is configured to print the matching part of the line in color, then command names that are in the first column will have their first letter highlighted:

$ git help -a|egrep --color=always '^  [a-zA-Z0-9]' | cat -v | head -n 1
^[[01;31m^[[K  a^[[m^[[Kdd                      grep                     remote

When bash sees this output, it thinks that ^[[01;31m^[[K, a^[[m^[[Kdd, grep and remote are possible commands. The first one won't turn up, the last two are correct, the second one is mangled.

You need to configure grep not to use colors when its output is not on a terminal. If you've aliased egrep to egrep --color=always (and ditto for grep and fgrep), change that to --color=auto. If you've set the GREP_OPTIONS variable somewhere, change --color=always to --color=auto there.

Best Answer

Related Solutions

The difference between hostname, hostname –fqdn, and hostname -A

bash – Strange Characters in GIT Completion

Related Question