encrypt file in batch mode

[Fourhundred Thecat]

On 02/11/2019 16.51, Tony Lane via Gnupg-users wrote:
> On 11/2/19 10:35 AM, Fourhundred Thecat wrote:
>
>> how can I simply encrypt a file in "batch mode", ie in a script, without
>> user interaction, without need for the user to type password, without
>> gpg agent?
>
> gpg --batch --yes --passphrase="pw" --pinentry-mode loopback -o zz -esr user at domain.com zz.gpg

Unfortunately, this does not work. I get same error as before (pasted
below).

Also, what is the purpose of --passphrase="pw", when I want to encrypt
using public key ?


$ gpg --batch --yes --passphrase="pw" --pinentry-mode loopback -o zz.gpg
-esr user at domain.com zz

gpg: starting migration from earlier GnuPG versions
gpg: failed to start agent '/usr/bin/gpg-agent': No such file or directory
gpg: can't connect to the agent: No such file or directory
gpg: error: GnuPG agent unusable. Please check that a GnuPG agent can be
started.
gpg: migration aborted
gpg: failed to start agent '/usr/bin/gpg-agent': No such file or directory
gpg: can't connect to the agent: No such file or directory
gpg: failed to start agent '/usr/bin/gpg-agent': No such file or directory
gpg: can't connect to the agent: No such file or directory
gpg: keydb_search failed: No agent running
gpg: no default secret key: No agent running
gpg: zz: sign+encrypt failed: No agent running