Sleep Display on Mac

#include <CoreFoundation/CoreFoundation.h>
#include <IOKit/IOKitLib.h>

int main(void)
{
    io_registry_entry_t r = IORegistryEntryFromPath(kIOMasterPortDefault, "IOService:/IOResources/IODisplayWrangler");
    if(!r) return 1;
    int err = IORegistryEntrySetCFProperty(r, CFSTR("IORequestIdle"), kCFBooleanTrue);
    IOObjectRelease(r);
    return err;
}