gnupg: Agent GET_CONFIRMATION
2.6.10 Ask for confirmation
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This command may be used to ask for a simple confirmation by presenting
a text and 2 buttons: Okay and Cancel.
GET_CONFIRMATION DESCRIPTION
DESCRIPTIONis displayed along with a Okay and Cancel button. Blanks
must be percent escaped or replaced by '+'. A 'X' may be used to
display confirmation dialog with a default text.
The agent either returns with an error or with a OK. Note, that the
length of DESCRIPTION is implicitly limited by the maximum length of a
command.