Maybe I am missing the point...
I had already considered attempting to 'install' a copy of a compiler in a directory which I can access. What I didn't know is where the existing compiler might be located so when bliako suggested using cp I followed his idea knowing that ~/bin already existed, I didn't try the mkdir command. I also think that there are only two outcomes from cp - it makes a copy of the file or it complains that it is not possible.

Given that I was pretty sure I couldn't do any harm with cp I thought I'd give it a go. But, had it worked, I would have consulted either the Great God Google or the Monastery or both before going further as I am not sure I fully understand what export does.

Have I got the point or am I missing it?