void
initialize_info_signal_handler (void)
{
#ifdef SA_NOCLDSTOP
/* (Based on info from Paul Eggert found in coreutils.) Don't use
HAVE_SIGACTION to decide whether to use the sa_handler, sa_flags,
sa_mask members, as some systems (Solaris 7+) don't define them. Use
SA_NOCLDSTOP instead; it's been part of POSIX.1 since day 1 (in 1988). */
info_signal_handler.sa_handler = info_signal_proc;
info_signal_handler.sa_flags = 0;
mask_termsig (&info_signal_handler.sa_mask);
#endif /* SA_NOCLDSTOP */
#if defined (SIGTSTP)
set_termsig (SIGTSTP, &old_TSTP);
set_termsig (SIGTTOU, &old_TTOU);
set_termsig (SIGTTIN, &old_TTIN);
#endif /* SIGTSTP */
#if defined (SIGWINCH)
set_termsig (SIGWINCH, &old_WINCH);
#endif
#if defined (SIGQUIT)
set_termsig (SIGQUIT, &old_QUIT);
#endif
#if defined (SIGINT)
set_termsig (SIGINT, &old_INT);
#endif
#if defined (SIGTERM)
set_termsig (SIGTERM, &old_TERM);
#endif
#if defined (SIGUSR1)
/* Used by DJGPP to simulate SIGTSTP on Ctrl-Z. */
set_termsig (SIGUSR1, &old_USR1);
#endif
}
static RETSIGTYPE
info_signal_proc (int sig)
{
signal_info *old_signal_handler = NULL;
#if !defined (HAVE_SIGACTION)
/* best effort: first increment this counter and later block signals */
if (term_conf_busy)
return;
term_conf_busy++;
#if defined (HAVE_SIGPROCMASK) || defined (HAVE_SIGSETMASK)
{
sigset_t nvar, ovar;
sigemptyset (&nvar);
mask_termsig (&nvar);
sigprocmask (SIG_BLOCK, &nvar, &ovar);
}
#endif /* HAVE_SIGPROCMASK || HAVE_SIGSETMASK */
#endif /* !HAVE_SIGACTION */
switch (sig)
{
#if defined (SIGTSTP)
case SIGTSTP:
case SIGTTOU:
case SIGTTIN:
#endif
#if defined (SIGQUIT)
case SIGQUIT:
#endif
#if defined (SIGINT)
case SIGINT:
#endif
{
#if defined (SIGTSTP)
if (sig == SIGTSTP)
old_signal_handler = &old_TSTP;
if (sig == SIGTTOU)
old_signal_handler = &old_TTOU;
if (sig == SIGTTIN)
old_signal_handler = &old_TTIN;
#endif /* SIGTSTP */
#if defined (SIGQUIT)
if (sig == SIGQUIT)
old_signal_handler = &old_QUIT;
#endif /* SIGQUIT */
#if defined (SIGINT)
if (sig == SIGINT)
old_signal_handler = &old_INT;
#endif /* SIGINT */
/* For stop signals, restore the terminal IO, leave the cursor
at the bottom of the window, and stop us. */
terminal_goto_xy (0, screenheight - 1);
terminal_clear_to_eol ();
fflush (stdout);
terminal_unprep_terminal ();
restore_termsig (sig, old_signal_handler);
UNBLOCK_SIGNAL (sig);
kill (getpid (), sig);
/* The program is returning now. Restore our signal handler,
turn on terminal handling, redraw the screen, and place the
cursor where it belongs. */
terminal_prep_terminal ();
set_termsig (sig, old_signal_handler);
/* window size might be changed while sleeping */
reset_info_window_sizes ();
}
break;
#if defined (SIGWINCH) || defined (SIGUSR1)
#ifdef SIGWINCH
case SIGWINCH:
#endif
#ifdef SIGUSR1
case SIGUSR1:
#endif
{
/* Turn off terminal IO, tell our parent that the window has changed,
then reinitialize the terminal and rebuild our windows. */
#ifdef SIGWINCH
if (sig == SIGWINCH)
old_signal_handler = &old_WINCH;
#endif
#ifdef SIGUSR1
if (sig == SIGUSR1)
old_signal_handler = &old_USR1;
#endif
terminal_goto_xy (0, 0);
fflush (stdout);
terminal_unprep_terminal (); /* needless? */
restore_termsig (sig, old_signal_handler);
UNBLOCK_SIGNAL (sig);
kill (getpid (), sig);
/* After our old signal handler returns... */
set_termsig (sig, old_signal_handler); /* needless? */
terminal_prep_terminal ();
reset_info_window_sizes ();
}
break;
#endif /* SIGWINCH || SIGUSR1 */
}
#if !defined (HAVE_SIGACTION)
/* at this time it is safer to perform unblock after decrement */
term_conf_busy--;
#if defined (HAVE_SIGPROCMASK) || defined (HAVE_SIGSETMASK)
{
sigset_t nvar, ovar;
sigemptyset (&nvar);
mask_termsig (&nvar);
sigprocmask (SIG_UNBLOCK, &nvar, &ovar);
}
#endif /* HAVE_SIGPROCMASK || HAVE_SIGSETMASK */
#endif /* !HAVE_SIGACTION */
}