replacing hard brake lines
 

I was bleeding the front brakes on my '82 today and noticed a puddle of fluid on the floor on the other side.
I noticed the steel line had a hole in it. Should I replace the entire line to the back or could I use a compression fitting to fix it?
The rest of the line looks good so I don't really want to replace the whole length unless I must.
What size are those lines anyway and how much is a flaring tool?
I never made this kind of repair before so I need as much advise as possible.