Passphrase as parameter in the command line

[ritter, horst (EDS CH)]

Dear Linux community,

I have been looking for weeks for a solution to the following problem.

How can I give gpg the passphrase as parameter in the commandline to decrypt
files, instead to type it in after GPG's request? 
I need this to automaticaly process a lot of files under UNIX, managed by
self written program.

I would be greatful for any hints, or any ideas, which may lead to a
solution.

Should you have any questions, or require further information, please do not
hesitate to contact me. 

Best regards,

Horst Ritter