assign command output to variable [duplicate]

Question

I'm cloning lots of virtual machines, and I need to edit /etc/hostname and replace old hostname with a new one.

then I would have to run

hostname new-server-name

and log out of the ssd session and login again.

I'm trying to make my job easier by doing this

echo "new-server-name" > /etc/hostname

if there is a way to assign the value to /etc/hostname to host command? Something like

cat /etc/hostname | hostname

but it doesn't work.

Answer 1

You probably want this:

hostname $(cat /etc/hostname)

And don't forget to edit /etc/hosts to reflect the correct host name as well.