: ${GNUPGHOME=$HOME/.gnupg}

GPGAGENT=/usr/bin/gpg-agent

if grep -qs '^[[:space:]]*use-agent' "$GNUPGHOME/gpg.conf" "$GNUPGHOME/options" &&
   test -x $GPGAGENT; then

   # Invoking gpg-agent with no arguments exits successfully if the agent
   # is already running on the standard socket
   if ! $GPGAGENT 2>/dev/null; then
       "$GPGAGENT" --daemon
   fi
   GPG_AGENT_INFO="${GNUPGHOME}/S.gpg-agent:0:1"
   export GPG_AGENT_INFO
   if grep -qs '^[[:space:]]*enable-ssh-support' "${GNUPGHOME}/gpg-agent.conf"; then
       SSH_AUTH_SOCK="${GNUPGHOME}/S.gpg-agent.ssh"
       export SSH_AUTH_SOCK
   fi
fi