what is the switch to let sed edit and save file

Shell Programming and Scripting
1

I remember there is a sed switch i can use to edit and save the file at the same time, but i cannot recall it at all.

so instead of

-> sed 's/A/B/' file > file-tmp
-> mv file-tmp file

what can i do to just let sed edit and save the "file"

2 
sed -i

?

3

yappppp!:D:D:D:D:D:D:D:D that is what i am looking for, interesting the manpage does not have it!

4

Yea, that's weird. Anyway you can remember it as "in place" editing.

5

As far as I know, only GNU sed supports editing in place.