linux - 如何检查 Linux 控制台屏幕保护程序是否有黑屏

Question

有没有办法以编程方式(通过 ioctl() 等)或通过读取/sys、/proc 或/dev 中的文件来检查屏幕是否已被 Linux 控制台屏幕保护程序黑屏？

谢谢和最好的问候，

君特

Answer 1

好的，检查了xset source code .相关代码部分为

#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");
            }
        }
    }
}

以防万一其他人需要这个;-)