process.c

#import <Carbon/Carbon.h>
#import <dlfcn.h>

/*
 * 컴파일 명령 : gcc process.c -framework CoreServices
 */
CFArrayRef CopyLaunchedApplicationsInFrontToBackOrder(void)
{    
    CFArrayRef (*_LSCopyApplicationArrayInFrontToBackOrder)(uint32_t sessionID) = NULL;
    void       (*_LSASNExtractHighAndLowParts)(void const* asn, UInt32* psnHigh, UInt32* psnLow) = NULL;
    CFTypeID   (*_LSASNGetTypeID)(void) = NULL;
    
    void *lsHandle = dlopen("/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/LaunchServices", RTLD_LAZY);
    if (!lsHandle) { return NULL; }
    
    _LSCopyApplicationArrayInFrontToBackOrder = (CFArrayRef(*)(uint32_t))dlsym(lsHandle, "_LSCopyApplicationArrayInFrontToBackOrder");
    _LSASNExtractHighAndLowParts = (void(*)(void const*, UInt32*, UInt32*))dlsym(lsHandle, "_LSASNExtractHighAndLowParts");
    _LSASNGetTypeID = (CFTypeID(*)(void))dlsym(lsHandle, "_LSASNGetTypeID");
    
    if (_LSCopyApplicationArrayInFrontToBackOrder == NULL || _LSASNExtractHighAndLowParts == NULL || _LSASNGetTypeID == NULL) { return NULL; }
    
    CFMutableArrayRef orderedApplications = CFArrayCreateMutable(kCFAllocatorDefault, 64, &kCFTypeArrayCallBacks);
    if (!orderedApplications) { return NULL; }
    
    CFArrayRef apps = _LSCopyApplicationArrayInFrontToBackOrder(-1);
    if (!apps) { CFRelease(orderedApplications); return NULL; }
    
    CFIndex count = CFArrayGetCount(apps);
    for (CFIndex i = 0; i < count; i++)
    {
        ProcessSerialNumber psn = {0, kNoProcess};
        CFTypeRef asn = CFArrayGetValueAtIndex(apps, i);
        if (CFGetTypeID(asn) == _LSASNGetTypeID())
        {
            _LSASNExtractHighAndLowParts(asn, &psn.highLongOfPSN, &psn.lowLongOfPSN);
            printf("%ld, ", psn.lowLongOfPSN);
        }
    }
    CFRelease(apps);
    
    CFArrayRef result = CFArrayGetCount(orderedApplications) == 0 ? NULL : CFArrayCreateCopy(kCFAllocatorDefault, orderedApplications);
    CFRelease(orderedApplications);
    return result;
}

int main() {
    CopyLaunchedApplicationsInFrontToBackOrder();
    /*
     * 실행 결과 예시 - 화면 순서별 프로세스 id
     635035, 2175507, 3748755, 364633, 3847083, 3556196, 3974090, 3961799, 1323331, 81940, 3584875, 905437
     */
}

/*
 * 백그라운드 제외한 프로세스 목록 (이름, id)
osascript -e 'tell application "System Events" to get {name, id} of (processes where background only is false)'

 Finder, Safari, iTerm2, Sourcetree, Music, Slack, Airmail 3, Telegram, Script Editor, Xcode, Preview, Activity Monitor, 81940, 364633, 635035, 905437, 1323331, 2175507, 3556196, 3584875, 3748755, 3847083, 3961799, 3974090
*/