can't get passphrase-fd option to work with GnuPG on HPUX when running a scheduled batch

[poney]

Hi, I'm new to the list. Sorry to join just when I need help with a problem, 
but goes.

We're trying to use the --passphrase-fd option with GnuPG from a shell script 
running through a batch run by scheduling software (ESP) on HPUX11.0 (not a 
good idea, I know, but it's what we need). We're using gpg version 1.0.7. 
Even though we can get the script to work when run interactively, regardless 
of how we use the option (using standard in or with a real file descriptor), 
the gpg command is failing when run through the scheduling software with the 
following error:

gpp: cannot open /dev/tty: No such device or address

I was assuming this had something to do with the process running the script 
not having access to standard in in the same way that the script has when we 
run it interactively. I've had the scheduling software su to the correct user 
to help set the environment correctly, but it still doesn't work. I'm looking 
for suggestions with trouble-shooting the problem.

Not sure if it's related, but I've never been able to successfuly use a real 
file descriptor with the --passphrase-fd option on this platform. This works 
in a shell script:

gpg --passphrase-fd 0 --decrypt myfile.txt.pgp <<!
mypassphrase
!

But this just prompts me for the passphrase:

gpg --passphrase-fd secretinfo.txt --decrypt myfile.txt.pgp

I've specified the path to the file in a number of ways, to try to ensure it 
can find the file, but it still won't work. I've also tried using the option 
in with a number of other options (--output, --yes, etc) since I've noticed 
that using some options together seems to change the behavior of the gpg 
command in unexpexted ways, but I still can't make it work. 

Any thoughts on what could be causing the problem, or suggestions about how 
to get around it?

Poney Carpenter