How to check if Linux console screensaver has blanked screen

Okay, checked the xset source code. The relevant code parts are

#include <X11/extensions/dpms.h>...Display* dpy = XOpenDisplay(NULL);...int dummy;CARD16 standby, suspend, off;BOOL onoff;CARD16 state;printf("DPMS (Energy Star):\n");if (DPMSQueryExtension(dpy, &dummy, &dummy)) {    if (DPMSCapable(dpy))     {        DPMSGetTimeouts(dpy, &standby, &suspend, &off);        printf ("  Standby: %d    Suspend: %d    Off: %d\n",                standby, suspend, off);        DPMSInfo(dpy, &state, &onoff);        if (onoff)         {            printf("  DPMS is Enabled\n");            switch (state)             {            case DPMSModeOn:                printf("  Monitor is On\n");                break;            case DPMSModeStandby:                printf("  Monitor is in Standby\n");                break;            case DPMSModeSuspend:                printf("  Monitor is in Suspend\n");                break;            case DPMSModeOff:                printf("  Monitor is Off\n");                break;            default:                printf("  Unrecognized response from server\n");            }        }    }}

Just in case anyone else needs this ;-)

You can parse the output of xset q with DISPLAY set, but it's not pretty.

$ xset qKeyboard Control:  auto repeat:  on    key click percent:  0    LED mask:  00000000  XKB indicators:    00: Caps Lock:   off    01: Num Lock:    off    02: Scroll Lock: off    03: Compose:     off    04: Kana:        off    05: Sleep:       off    06: Suspend:     off    07: Mute:        off    08: Misc:        off    09: Mail:        off    10: Charging:    off    11: Shift Lock:  off    12: Group 2:     off    13: Mouse Keys:  off  auto repeat delay:  250    repeat rate:  30  auto repeating keys:  00ffffffdffffbbf                        fadfffefffedffff                        9fffffffffffffff                        fff7ffffffffffff  bell percent:  50    bell pitch:  400    bell duration:  100Pointer Control:  acceleration:  20/10    threshold:  4Screen Saver:  prefer blanking:  yes    allow exposures:  yes  timeout:  0    cycle:  600Colors:  default colormap:  0x20    BlackPixel:  0    WhitePixel:  16777215Font Path:  /usr/share/fonts/misc,/usr/share/fonts/100dpi:unscaled,/usr/share/fonts/75dpi:unscaled,/usr/share/fonts/TTF,/usr/share/fonts/Type1,/usr/share/fonts/misc/,/usr/share/fonts/TTF/,/usr/share/fonts/Type1/,/usr/share/fonts/100dpi/,/usr/share/fonts/75dpi/,built-insDPMS (Energy Star):  Standby: 1200    Suspend: 1800    Off: 0  DPMS is Enabled  Monitor is OnFont cache:  Server does not have the FontCache Extension

I made an equivalent implementation of Günter's code in Python with ctypes.

import ctypesimport structctypes.cdll.LoadLibrary('libXext.so')libXext = ctypes.CDLL('libXext.so')DPMSFAIL = -1DPMSModeOn = 0DPMSModeStandby = 1DPMSModeSuspend = 2DPMSModeOff = 3def get_DPMS_state(display_name_in_byte_string=b':0'):    state = DPMSFAIL    if not isinstance(display_name_in_byte_string, bytes):        raise TypeError    display_name = ctypes.c_char_p()    display_name.value = display_name_in_byte_string    libXext.XOpenDisplay.restype = ctypes.c_void_p    display = ctypes.c_void_p(libXext.XOpenDisplay(display_name))    dummy1_i_p = ctypes.create_string_buffer(8)    dummy2_i_p = ctypes.create_string_buffer(8)    if display.value:        if libXext.DPMSQueryExtension(display, dummy1_i_p, dummy2_i_p)\           and libXext.DPMSCapable(display):            onoff_p = ctypes.create_string_buffer(1)            state_p = ctypes.create_string_buffer(2)            if libXext.DPMSInfo(display, state_p, onoff_p):                onoff = struct.unpack('B', onoff_p.raw)[0]                if onoff:                    state = struct.unpack('H', state_p.raw)[0]        libXext.XCloseDisplay(display)    return state

Calling sample is on my github.