When I run a Linux system I tend to have at least 30 terminal windows open. Some of these are logged into the other machines in my house. As of this writing I am logged into laptop1, laptop4, and gabi1 (my girlfriend's laptop running Fedora 20). I found a while back that if the prompt were different on these terminals it was harder for me to get mixed up and type the right command but on the wrong computer. Needless to say that could be a disaster. For a while I would change the prompt manually but that got old very quickly. One day I found almost by accident a really cool solution to this problem. I have used this technique on Red Hat Enterprise Linux, Fedora, and CentOS and so it should work on your system as well (with maybe a little bit of tweaking).

These lines are in the $HOME/.bashrc file on all my systems:

# Modified 1/17/2014
set | grep XAUTHORITY
rc=$?
if [ $rc -eq 0 ] ; then
 PS1="\h \w # "
else
 PS1="\h \h \h \h \w # "
fi

So what this does is use the set command to grep for the string XAUTHORITY. That string is only in the environment on the local machine. So when you open a terminal locally on big1 it uses the normal prompt. However, if you ssh to another system the string is not there and so it uses the long expanded prompt.

Here is a screenshot of my system showing how this looks: