Darling – MacOS translation layer for Linux(darlinghq.org)

  IMPLEMENTATION NOTES
    The pselect() function is implemented in the C library as a wrapper
    around select().

  #include <errno.h>
  #include <signal.h>
  #include <stdio.h>
  #include <sys/select.h>
  #include <unistd.h>
  #include <err.h>
  
  static int interrupted;
  
  static void
  interrupt(int signo)
  {
    interrupted = signo;
  }
  
  int
  main(void)
  {
    struct timespec timeout = { 3, 0 };
    sigset_t empty, block;
    int n;
  
    sigemptyset(&empty);
    sigemptyset(&block);
  
    sigaddset(&block, SIGHUP);
    sigprocmask(SIG_BLOCK, &block, NULL);
  
    signal(SIGHUP, &interrupt);
    raise(SIGHUP);
  
    while (!interrupted) {
      /*
       * If pselect does not atomically unblock signals, pselect
       * will never be interrupted and we'll lose the signal until
       * something else wakes us up AND we remember to check even
       * though we never saw EINTR.
       */
      n = pselect(0, NULL, NULL, NULL, &timeout, &empty);
      if (n == -1 && errno != EINTR) {
        err(1, "pselect");
      } else if (n == 0) {
        errx(1, "timed out");
      }
    }
  
    if (interrupted != SIGHUP)
      errx(1, "wrong signal (got %d, expected %d)",
          interrupted, SIGHUP);
  
    puts("OK");
    
    return 0;  
  }