Commands are not distinguished from options except for the fact that only one command is allowed.
--version--help-h--dump-options--serverstdin. The
default mode is to create a socket and listen for commands there.
--daemon [command line]eval $(gpg-agent --daemon) to setup the
environment variables. The option --write-env-file is
another way commonly used to do this. Yet another way is creating
a new process as a child of gpg-agent: gpg-agent --daemon
/bin/sh. This way you get a new shell with the environment setup
properly; if you exit from this shell, gpg-agent terminates as well.