Copy and Rename

I want to create a oneclick button to make a backup copy of a file.

So basically it copies from [filename] to [filename].bak.

I know this should be simple, but I can't figure out the combination of command to string together.


Thanks. I knew it would be simple.

If I wanted to make it smarter and automatically add a integer if a bak file with the same already exists, how would I do that.

You don't have to go too much trouble, if you know the name of the command I can look up how to use it.

Add WHENEXISTS=rename to the command and it will renumber automatically when a filename clashes.