Function signal_setup

src/ls.c:1586–1633

   otherwise restore to the default.  */

static void
signal_setup (bool init)
{
  /* The signals that are trapped, and the number of such signals.  */
  static int const stop_sig[] =
    {
      /* This one is handled specially.  */
      SIGTSTP,
    };

  enum { nsigs = countof (term_sig), nstop = countof (stop_sig) };

  if (init)
    {
      struct sigaction act;

      sigemptyset (&caught_signals);
      for (int j = 0; j < nsigs + nstop; j++)
        {
          int sig = j < nsigs ? term_sig[j]: stop_sig[j - nsigs];
          sigaction (sig, NULL, &act);
          if (act.sa_handler != SIG_IGN)
            sigaddset (&caught_signals, sig);
        }

      act.sa_mask = caught_signals;
      act.sa_flags = SA_RESTART;

      for (int j = 0; j < nsigs + nstop; j++)
        {
          int sig = j < nsigs ? term_sig[j]: stop_sig[j - nsigs];
          if (sigismember (&caught_signals, sig))
            {
              act.sa_handler = j < nsigs ? sighandler : stophandler;
              sigaction (sig, &act, NULL);
            }
        }
    }
  else /* restore.  */
    {
      for (int j = 0; j < nsigs + nstop; j++)
        {
          int sig = j < nsigs ? term_sig[j]: stop_sig[j - nsigs];
          if (sigismember (&caught_signals, sig))
            signal (sig, SIG_DFL);
        }
    }
}

static void
signal_init (void)