How to start gnupg?

[Ángel]

On 2018-12-01 at 22:33 +0000, John Broyles wrote:
> I just installed gnupg software from source.  (...) I typed sudo apt
> install gnupg

When you say that you are installing a software from source, it usually
means that you downloaded the source code (usually a tgz) and compiled
it yourself.

As you then mention that what you did was a sudo apt install gnupg, you
were installing gnupg from Ubuntu 16.04 package manager.




> when I typed sudo apt install gnupg, the response was that the current
> version was the latest.  So, I assume that that means that the program
> is installed.  

Yes. That means that you (already) have installed the latest version of
gnupg package that is packaged in Ubuntu 16.04


> However, how do I start and use the program?  I have a large file that
> was encrypted with PGP and I want to decrypt it.  Am I missing
> something simple?  I am using Ubuntu 16.04 operating system.  I can
> not find this program in the installed program list.

If you want a visual program to use for this, I would recommend you to
install kleopatra


If you are fine using the command line, run in a terminal
 gpg --decrypt-files <file encrypted with PGP>


Note that if it was encrypted to your public key, you would need to
first import it with gpg --import, otherwise the above command will
complain it doesn't have the needed key (the error message should point
you in the right direction, though).

The requirement to have is 
Graphical frontends like kleopatra will also allow you to decrypt files
(File -> Decrypt/Verify files), but nevertheless you will need to have
your key imported in order to do that (it allows you to do that
graphically, though).

Best regards