u = undo r = replace
Is there one key shortcut for redo ?
ctrl + r is a two key stroke (in my thinking),
and I often hit the wrong combination (I just recently switch to Mac)
Or is it possibile to map my own key stroke?
But I strongly recommend against you using "r" as your mapped key.
You could map one of the F-keys for redo by putting the following in your .vimrc
You can enter those special characters ( and ^R) by pressing ^V (ctrl-v) first.
For more details on entering special characters, :help i_CTRL-V