how to strip domain from hostname in bash

Question

How do I strip domain from hostname in pure Bash?

Example:

hostname = myserver.site.mydomain.com
output=${hostname#*.*}

will give

site.mydomain.com

while

hostname = myserver.site.mydomain.com
output=${hostname%*.*}

will give

myserver.site.mydomain

I want only "myserver"

Any ideas?

I wish to use pure Bash, not sed, awk, cut, etc.

Answer 1

What about:

hostname=myserver.site.mydomain.com
output=${hostname%%.*}

%% should remove longest match from tail.