I just would like to see a p4 branch -i example, so that it reads the branch mapping from standard input without invoking an editor
Do you mean something like:
C:\Users\Bryan>type foo.br
Branch: foo
Owner: Bryan
Options: unlocked
View:
//depot/main/... //depot/bryan/...
C:\Users\Bryan>type foo.br | p4 branch -i
Branch foo saved.