passphrase and windows

[V+]

Hi all,
I'm using GNUPG 1-0-1a for Windows. In particular I'm invoking gpg from
inside a C++ code and I need to read the passphrase from a file (I had no
choice) in order to sign a file, but I don't know how to do it. I tried with
'--passphrase-fd' option but I don't understand how it works under Windows.
May anybody help me, please?

Thanks in advance.

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_/ Vicente Mas                   _/                       _/
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