Clarifying the GnuPG License

[Navin]

Hi,

Since GnuPG comes under the GPL, I would like to clarify if a person's 
proprietary software makes use of GnuPG purely by invocation of the 
commandline commands, and the GnuPG exe's and DLL's are bundled 
unmodified with the person's proprietary software, can the person use 
GnuPG commercially in this manner without having to publish his/her 
source code?

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Nav