deleting keys in batch

[John Kane]

We're able to force 'Yes' responses with this:
  gpg --command-fd 0 --delete-secret-and-public-key KEYNAME <YY

where YY is a text file containing:
Y
Y
(with linebreak / carriage-return after each "Y")
We found out the hard way that "y" doesn't work; use "Y"s.  This
should be portable across all systems which support stdin, pipes,
and redirection.
In general, you can use " --status-fd 2 --command-fd 0 " to make
GnuPG prompt you explicitly for confirmation, which you can type
interactively from the keyboard.  Once you determine the exact
sequence of responses, you can record them in a text file.