/****************************************************************************
- * Copyright (c) 1998,1999,2000 Free Software Foundation, Inc. *
+ * Copyright (c) 1998-2001,2002 Free Software Foundation, Inc. *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the *
/****************************************************************************
* Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995 *
* and: Eric S. Raymond <esr@snark.thyrsus.com> *
+ * and: Thomas Dickey 1995-2001 *
****************************************************************************/
/*
** The routine _nc_signal_handler().
**
*/
-
#include <curses.priv.h>
-#include <signal.h>
#include <SigAction.h>
#if SVR4_ACTION && !defined(_POSIX_SOURCE)
#define _POSIX_SOURCE
#endif
-MODULE_ID("$Id: lib_tstp.c,v 1.22 2000/09/02 18:33:17 tom Exp $")
+MODULE_ID("$Id: lib_tstp.c,v 1.30 2002/05/18 19:55:38 tom Exp $")
#if defined(SIGTSTP) && (HAVE_SIGACTION || HAVE_SIGVEC)
#define USE_SIGTSTP 1
#define USE_SIGTSTP 0
#endif
+#ifdef TRACE
+static const char *
+signal_name(int sig)
+{
+ switch (sig) {
+ case SIGALRM:
+ return "SIGALRM";
+#ifdef SIGCONT
+ case SIGCONT:
+ return "SIGCONT";
+#endif
+ case SIGINT:
+ return "SIGINT";
+ case SIGQUIT:
+ return "SIGQUIT";
+ case SIGTERM:
+ return "SIGTERM";
+#ifdef SIGTSTP
+ case SIGTSTP:
+ return "SIGTSTP";
+#endif
+#ifdef SIGTTOU
+ case SIGTTOU:
+ return "SIGTTOU";
+#endif
+#ifdef SIGWINCH
+ case SIGWINCH:
+ return "SIGWINCH";
+#endif
+ default:
+ return "unknown signal";
+ }
+}
+#endif
+
/*
* Note: This code is fragile! Its problem is that different OSs
* handle restart of system calls interrupted by signals differently.
sigemptyset(&act.sa_mask);
act.sa_flags = 0;
act.sa_handler = SIG_IGN;
- if (sigaction(sig, &act, (sigaction_t *) 0) == 0)
+ if (sigaction(sig, &act, NULL) == 0)
#else
if (signal(sig, SIG_IGN) != SIG_ERR)
#endif
* If the given signal is still in its default state, set it to the given
* handler.
*/
-#if HAVE_SIGACTION || HAVE_SIGVEC
static int
-CatchIfDefault(int sig, sigaction_t * act)
+CatchIfDefault(int sig, RETSIGTYPE (*handler) (int))
{
+ int result;
+#if HAVE_SIGACTION || HAVE_SIGVEC
sigaction_t old_act;
+ sigaction_t new_act;
+
+ memset(&new_act, 0, sizeof(new_act));
+ sigemptyset(&new_act.sa_mask);
+#ifdef SA_RESTART
+#ifdef SIGWINCH
+ if (sig != SIGWINCH)
+#endif
+ new_act.sa_flags |= SA_RESTART;
+#endif /* SA_RESTART */
+ new_act.sa_handler = handler;
- if (sigaction(sig, (sigaction_t *) 0, &old_act) == 0
+ if (sigaction(sig, NULL, &old_act) == 0
&& (old_act.sa_handler == SIG_DFL
+ || old_act.sa_handler == handler
#if USE_SIGWINCH
|| (sig == SIGWINCH && old_act.sa_handler == SIG_IGN)
#endif
)) {
- (void) sigaction(sig, act, (sigaction_t *) 0);
- return TRUE;
+ (void) sigaction(sig, &new_act, NULL);
+ result = TRUE;
+ } else {
+ result = FALSE;
}
- return FALSE;
-}
-#else
-static int
-CatchIfDefault(int sig, RETSIGTYPE(*handler) (int))
-{
- void (*ohandler) (int);
+#else /* !HAVE_SIGACTION */
+ RETSIGTYPE (*ohandler) (int);
ohandler = signal(sig, SIG_IGN);
if (ohandler == SIG_DFL
+ || ohandler == handler
#if USE_SIGWINCH
|| (sig == SIGWINCH && ohandler == SIG_IGN)
#endif
) {
signal(sig, handler);
- return TRUE;
+ result = TRUE;
} else {
signal(sig, ohandler);
- return FALSE;
+ result = FALSE;
}
-}
#endif
+ T(("CatchIfDefault - will %scatch %s",
+ result ? "" : "not ", signal_name(sig)));
+ return result;
+}
/*
* This is invoked once at the beginning (e.g., from 'initscr()'), to
* The XSI document implies that we shouldn't keep the SIGTSTP handler if
* the caller later changes its mind, but that doesn't seem correct.
*/
-void
+NCURSES_EXPORT(void)
_nc_signal_handler(bool enable)
{
-#if USE_SIGTSTP /* Xenix 2.x doesn't have SIGTSTP, for example */
- static sigaction_t act, oact;
- static int ignore;
-
- if (!ignore) {
- if (!enable) {
- act.sa_handler = SIG_IGN;
- sigaction(SIGTSTP, &act, &oact);
- } else if (act.sa_handler) {
- sigaction(SIGTSTP, &oact, NULL);
- } else { /*initialize */
- sigemptyset(&act.sa_mask);
- act.sa_flags = 0;
-#if USE_SIGWINCH
- act.sa_handler = sigwinch;
- CatchIfDefault(SIGWINCH, &act);
-#endif
+ static bool initialized = FALSE;
+ T((T_CALLED("_nc_signal_handler(%d)"), enable));
+#if USE_SIGTSTP /* Xenix 2.x doesn't have SIGTSTP, for example */
+ {
+ static bool ignore_tstp = FALSE;
+
+ if (!ignore_tstp) {
+ static sigaction_t act, oact;
+
+ if (!enable) {
+ act.sa_handler = SIG_IGN;
+ sigaction(SIGTSTP, &act, &oact);
+ } else if (act.sa_handler != SIG_DFL) {
+ sigaction(SIGTSTP, &oact, NULL);
+ } else if (sigaction(SIGTSTP, NULL, &oact) == 0
+ && (oact.sa_handler == SIG_DFL)) {
+ sigemptyset(&act.sa_mask);
#ifdef SA_RESTART
- act.sa_flags |= SA_RESTART;
+ act.sa_flags |= SA_RESTART;
#endif /* SA_RESTART */
- act.sa_handler = cleanup;
- CatchIfDefault(SIGINT, &act);
- CatchIfDefault(SIGTERM, &act);
-
- act.sa_handler = tstp;
- if (!CatchIfDefault(SIGTSTP, &act))
- ignore = TRUE;
+ act.sa_handler = tstp;
+ (void) sigaction(SIGTSTP, &act, NULL);
+ } else {
+ ignore_tstp = TRUE;
+ }
}
}
-#else /* !USE_SIGTSTP */
- if (enable) {
-#if HAVE_SIGACTION || HAVE_SIGVEC
- static sigaction_t act;
- sigemptyset(&act.sa_mask);
-#if USE_SIGWINCH
- act.sa_handler = sigwinch;
- CatchIfDefault(SIGWINCH, &act);
-#endif
-#ifdef SA_RESTART
- act.sa_flags |= SA_RESTART;
-#endif /* SA_RESTART */
- act.sa_handler = cleanup;
- CatchIfDefault(SIGINT, &act);
- CatchIfDefault(SIGTERM, &act);
-
-#else /* !(HAVE_SIGACTION || HAVE_SIGVEC) */
+#endif /* !USE_SIGTSTP */
- CatchIfDefault(SIGINT, cleanup);
- CatchIfDefault(SIGTERM, cleanup);
+ if (!initialized) {
+ if (enable) {
+ CatchIfDefault(SIGINT, cleanup);
+ CatchIfDefault(SIGTERM, cleanup);
#if USE_SIGWINCH
- CatchIfDefault(SIGWINCH, sigwinch);
+ CatchIfDefault(SIGWINCH, sigwinch);
#endif
-#endif /* !(HAVE_SIGACTION || HAVE_SIGVEC) */
+ initialized = TRUE;
+ }
}
-#endif /* !USE_SIGTSTP */
+ returnVoid;
}
projects / ncurses.git / blobdiff