There has been a fair amount of confusion over the difference between the
host file and
hosts (plural) file. Both files should be in the
>system>stcp directory but there the similarity ends.
hosts file is used for IP address to name resolution. Depending on your configuration you may or may not need a
hosts file. If all your names can be resolved via your Domain Name Server (DNS) then the
hosts file is optional, although most sites still have one with a “
127.0.0.1 localhost” entry.
host file holds a string containing the name of the system. Ideally, the name is resolvable to an IP address. The
host file is read by the “
gethostname” function. Many applications call this function to get the host name and fault with a “
Bad file number” error when it cannot be found. For example:
gethostname: Bad file number.
The applications that come to mind are SSH, SSL, and Samba. There are probably others and I guarantee that there will be more in future as we port more applications.
To create the
host file just run the
hostname command with the system name as an argument. The command will echo the name on the next line:
You will need write access to the
>system>stcp directory to create the file. If you run the command without arguments it will display the system name, which you can also do by displaying the file:
%azvos#m17_mas>system>stcp>host 12-11-07 16:14:44 mst
You can change the name stored in the file just by running the
hostname command with a new name:
However, be careful of specifying names with special characters (like % and #) as some applications use the name to create a temporary file and the special characters may prevent that:
gpg: failed to create temporary file `/SysAdmin/Noah_Davids/.gnupg/._lk40009dd0.#m17.286361238': File name too long or contains invalid characters.