I want to detect from a shell script (more specifically .zshrc) if it is controlled through SSH. I tried the HOST variable but it's always the name of the computer which is running the shell. Can I access the hostname where the SSH session is coming from? Comparing the two would solve my problem.
Every time I log in there is a message stating the last login time and host:
Last login: Fri Mar 18 23:07:28 CET 2011 from max on pts/1 Last login: Fri Mar 18 23:11:56 2011 from max
This means the server has this information.