decrypt aes256 encrypted file without gpg-agent

[Fourhundred Thecat]

 > On 2020-06-30 08:55, Ralph Seichter via Gnupg-users wrote:
> * Fourhundred Thecat:
>>
> What insight do you have in the design and development of GnuPG; in its
> goals and restrictions? There is a difference between you not liking
> something for a personal reason, and objectively "bad design". You are
> entitled to your opinion of course, but unless you can demonstrate the
> skills to come up with a better design for free software that offers the
> same functionality as GnuPG, that opinion does not mean so much.

I am basing my judgment on universal principles, that apply not only to
gpg or other software, but design of any systems in general.

One such principle is a having distinct modes of operation for:

1) maintenance (read/write operations)
2) general use (read-only operations)

In case of gpg, there is one mode where you generate your key pair,
change configuration files, or any other read-write operation.

But for general usage, there is no reason for the key pair to need to be
writable.

Take a car, as an analogy:

Imagine what a mess it would be, if you tried to design a car where the
engine can be replaced while you are driving. I have no experience
designing cars, but that does not prevent me from seeing this would be
bad design specification. Maintenance and usage are two different modes,
and should not be mixed.