}

  #
  # NOTE: This procedure returns a string argument value, which may contain
  #       spaces, for use with the [exec] command.  The value argument is
  #       the string value to format as an [exec] argument.
  #
  # <internal>
  proc formatExecArgument { value } {
    if {[isEagle]} then {
      return [appendArgs \" $value \"]
    } else {
      return $value
    }
  }

      if {[catch {
        eval exec -success Success $openPgpInstalledCommand
      } result]} then {
        error "cannot use OpenPGP: may not be installed and/or configured"
      }
    } else {
      if {[catch {
        eval exec [subst $openPgpInstalledCommand]
        eval exec $openPgpInstalledCommand
      } result]} then {
        error "cannot use OpenPGP: may not be installed and/or configured"
      }
    }

    if {![info exists result] || \
        ![regexp -- $openPgpInstalledPattern $result]} then {