Add symbol to the end of every other line
I'm sure that this is extremely simple, but don't understand the sed command enough to do it myself.
Basically, if I have a list such as that below, I want to add a ; symbol to the end of every other line:
So I want to alter the above to give the following:
Thanks to anyone that can help. I have managed to add a symbol to the end of EVERY line, but not every OTHER line.