#autoload

local giveup='Cannot check validity of gpg-agent settings; assuming OK.'

if ( ! true ); then
  echo 'zsh has ( ! true ) negated subshell bug!'
# Have rewritten the below so this doesn't matter.  Still
# nice to be alerted to it now and again though.
#   echo $giveup
#   return 0
fi

if [[ -z "$GPG_AGENT_INFO" ]]; then
  echo '$GPG_AGENT_INFO not set.'
  return 1
fi

if ! [[ -e /proc ]]; then
  echo "/proc didn't exist!"
  echo $giveup
  return 0
fi

GPG_AGENT_SOCK="${GPG_AGENT_INFO%:1}"
GPG_AGENT_PID="${GPG_AGENT_SOCK##*:}"
GPG_AGENT_SOCK="${GPG_AGENT_SOCK%:$GPG_AGENT_PID}"

if [[ ! -e /proc/$GPG_AGENT_PID ]]; then
  echo "\$GPG_AGENT_PID set to non-existent pid ($GPG_AGENT_PID)."
  return 1
fi

if [[ ! -e /proc/$GPG_AGENT_PID/cmdline ]]; then
  echo "/proc/$GPG_AGENT_PID/cmdline doesn't exist!"
  return 1
fi

if ! grep -q gpg-agent /proc/$GPG_AGENT_PID/cmdline; then
  echo "/proc/$GPG_AGENT_PID/cmdline wrong"
  return 1
fi

[[ -S "$GPG_AGENT_SOCK" ]]