Redirecting STDIN

[James Board]

I'm trying to encode a file in a shell script on a linux machine.  The script is getting stuck on an interactive question for which the answer is always 'y' (yes).  I tried redirecting stdin from a file, and with 'echo "y" | ....", but that doesn't work for some reason (it works with other programs that take interactive input from the user).  I also tried the --yes option, but this doesn't work either.

How can I redirect STDIN to pgp so that questions are always answered 'y' and my script won't have to wait on user inputs?