decrypt stdin with passphrase in

[Robert]

"darren chamberlain dlc-at-users.sourceforge.net |gpg|"
<dbdthgsjph0t@sneakemail.com> writes:
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>* Robert <qg7l80202 at sneakemail.com> [2003-06-25 10:50]:
>> Now, what I'd REALLY like to find is a way to do this without writing
>> either the passphrase OR the encrypted block of text to disk...  My
>> problem seems to be that I can't pipe anything FROM any stream except
>> stdout and I can't pipe TO any stream except stdin.
>
>The example showed you how to use fd 3 as input -- that's the
>"3<passfile" bit...
>
>(darren)
>
But using that syntax means I have to have the passphrase written to disk,
right?
And I've got to avoid doing that.
Is there some way to sent things to file descriptor 3 other than
"3<filename"? 
I guess what I'm looking for is something like "echo 'passphrase' 3| gpg
...", but there is no "3|" in ksh or sh as far as I can tell...