Getting and setting the Mac OS X hostname

Periodically my Mac hostname appears to go walkabout. I've yet to resolve why, and have lost the will look very carefully (I think it's a DNS/DHCP issue). Changing it via System Settings does not always work.

In the meantime, re-setting the hostname can easily be achieved from the command line.

There are three potential hostnames that can be set or retrieved:

• HostName … which is the primary hostname and should be fully qualified e.g. MyMac.local (if not accessible over the internet) or swarms.theapiarist.org.
• LocalHostName … which is the name used on the local network, the Bonjour hostname, for file sharing e.g. MyMac.local, when setting this omit the domain and the system automagically appends .local.
• ComputerName … the computer name, which lacks any domain information, and is the name used by the Finder e.g. MyMac

The current names can be retrieved using:

sudo scutil --get <Name> where <Name> is one of the words in bold in the list above e.g. sudo scutil --get LocalHostName

And can be changed using:

sudo scutil --set <Name> <new host name> e.g. sudo scutil --set ComputerName MyMac

After setting a new hostname flush the DNS cache using:

dscacheutil -flushcache

The hostname appears to be set in at least two separate locations, and echo $HOSTNAME only returns one of them. Being OS X, there's no /etc/hostname of course 😞.

Further information:

• An old discussion on StackExchange on setting the hostname from the command line
• More than you'd ever want to know about scutil is available by typing man scutil at the command prompt

#apple
#osx