A mpv script for turn off dpms while playing video automatically

turn-off-dpms.lua

-- save this file to $XDG_CONFIG_HOME/mpv/scripts/

local dpms_mod = nil

-- local function dpms_mod_start(event)
--    print("RUN dpms mod start", dpms_mod)
--    if dpms_mod == nil then
--       -- This code was checked on xset 1.2.3
--       if os.execute("[ `xset q | sed -n '/^DPMS/,${/^  DPMS/s/^  DPMS is //p}'` == Enabled ]") == 0 then
--          dpms_mod = true
--       else
--          dpms_mod = false
--       end
--    end
-- end

-- mp.register_event("video-reconfig", dpms_mod_start)

local function on_property_change(name, value)
   print('RUN on property change', value, dpms_mod)
   if dpms_mod == nil and value then
      -- This code was checked on xset 1.2.3
      if os.execute("[ `xset q | sed -n '/^DPMS/,${/^  DPMS/s/^  DPMS is //p}'` == Enabled ]") == 0 then
         dpms_mod = true
      else
         dpms_mod = false
      end
   end
end

mp.observe_property("vo-configured", "bool", on_property_change)

local function dpms_mod_stop(event)
   if dpms_mod then
      os.execute("xset +dpms")
   end
end

mp.register_event("shutdown", dpms_mod_stop)

local function dpms_on_play(event)
   if dpms_mod then
      os.execute("xset -dpms")
   end
end

mp.register_event("playback-restart", dpms_on_play)

local function dpms_on_pause(name, value)
   if dpms_mod then
      if value then
         os.execute("xset +dpms")
      else
         os.execute("xset -dpms")
      end
   end
end

mp.observe_property("pause", "bool", dpms_on_pause)

Wouldn't checking the return value of grep(1) also work? For example

if xset q|grep -q 'DPMS.*Enabled'; then
    echo DPMS is enabled
else
    echo DPMS is disabled
fi