sleep-in-background.c

#include <windows.h>
#include <stdio.h>

typedef LONG (NTAPI *NtSuspendProcess)(IN HANDLE ProcessHandle);

void suspend(DWORD processId)
{
   HANDLE processHandle = OpenProcess(PROCESS_ALL_ACCESS, FALSE, processId);

   NtSuspendProcess pfnNtSuspendProcess = (NtSuspendProcess)GetProcAddress(
       GetModuleHandle("ntdll"), "NtSuspendProcess");

   pfnNtSuspendProcess(processHandle);
   CloseHandle(processHandle);
}

void resume(DWORD processId)
{
   HANDLE processHandle = OpenProcess(PROCESS_ALL_ACCESS, FALSE, processId);

   NtSuspendProcess pfnNtResumeProcess = (NtSuspendProcess)GetProcAddress(
       GetModuleHandle("ntdll"), "NtResumeProcess");

   pfnNtResumeProcess(processHandle);
   CloseHandle(processHandle);
}


int main() {
  printf("1\n");
  // suspend(10196);
  // resume(10196);
  GetForegroundWindow();
  printf("2\n");

  char array[320];
  for (int i = 0; i < 10; ++i) {
    GetWindowText(GetForegroundWindow(), array, 300);
    printf("%s\n", array);
    sleep(2);
  }
  printf("3\n");
  // MessageBox(GetForegroundWindow(), "Text", "Title", Flags);
  return 0;
}