Passing in a Passphrase to GPG via Bash

[Rick Funderburg]

I am trying to make a bash backup script that will encrypt the output 
using symmetric encryption through GPG.  How do I pass in the passphrase 
securely?  Right now, I have the passphrase hard coded as a variable in 
the script.  GPG can read the passphrase from a specified file 
descriptor.  How do I hook up the two in a secure way?  If i just use 
the environment variable as an argument to a program (like echo), my 
passphrase could show up in process lists.

-- Rick

--
KPLUG-List@kernel-panic.org
http://www.kernel-panic.org/cgi-bin/mailman/listinfo/kplug-list