diff options
Diffstat (limited to 'ncurses-5.3/ncurses/tty/lib_tstp.c')
| -rw-r--r-- | ncurses-5.3/ncurses/tty/lib_tstp.c | 399 |
1 files changed, 0 insertions, 399 deletions
diff --git a/ncurses-5.3/ncurses/tty/lib_tstp.c b/ncurses-5.3/ncurses/tty/lib_tstp.c deleted file mode 100644 index 8f6b143..0000000 --- a/ncurses-5.3/ncurses/tty/lib_tstp.c +++ /dev/null @@ -1,399 +0,0 @@ -/**************************************************************************** - * 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 * - * "Software"), to deal in the Software without restriction, including * - * without limitation the rights to use, copy, modify, merge, publish, * - * distribute, distribute with modifications, sublicense, and/or sell * - * copies of the Software, and to permit persons to whom the Software is * - * furnished to do so, subject to the following conditions: * - * * - * The above copyright notice and this permission notice shall be included * - * in all copies or substantial portions of the Software. * - * * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * - * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * - * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * - * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, * - * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * - * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR * - * THE USE OR OTHER DEALINGS IN THE SOFTWARE. * - * * - * Except as contained in this notice, the name(s) of the above copyright * - * holders shall not be used in advertising or otherwise to promote the * - * sale, use or other dealings in this Software without prior written * - * authorization. * - ****************************************************************************/ - -/**************************************************************************** - * Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995 * - * and: Eric S. Raymond <esr@snark.thyrsus.com> * - * and: Thomas Dickey 1995-2001 * - ****************************************************************************/ - -/* -** lib_tstp.c -** -** The routine _nc_signal_handler(). -** -*/ -#include <curses.priv.h> - -#include <SigAction.h> - -#if SVR4_ACTION && !defined(_POSIX_SOURCE) -#define _POSIX_SOURCE -#endif - -MODULE_ID("$Id$") - -#if defined(SIGTSTP) && (HAVE_SIGACTION || HAVE_SIGVEC) -#define USE_SIGTSTP 1 -#else -#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. - * The ncurses code needs signal-call restart to happen -- otherwise, - * interrupted wgetch() calls will return FAIL, probably making the - * application think the input stream has ended and it should - * terminate. In particular, you know you have this problem if, when - * you suspend an ncurses-using lynx with ^Z and resume, it dies - * immediately. - * - * Default behavior of POSIX sigaction(2) is not to restart - * interrupted system calls, but Linux's sigaction does it anyway (at - * least, on and after the 1.1.47 I (esr) use). Thus this code works - * OK under Linux. The 4.4BSD sigaction(2) supports a (non-portable) - * SA_RESTART flag that forces the right behavior. Thus, this code - * should work OK under BSD/OS, NetBSD, and FreeBSD (let us know if it - * does not). - * - * Stock System Vs (and anything else using a strict-POSIX - * sigaction(2) without SA_RESTART) may have a problem. Possible - * solutions: - * - * sigvec restarts by default (SV_INTERRUPT flag to not restart) - * signal restarts by default in SVr4 (assuming you link with -lucb) - * and BSD, but not SVr3. - * sigset restarts, but is only available under SVr4/Solaris. - * - * The signal(3) call is mandated by the ANSI standard, and its - * interaction with sigaction(2) is described in the POSIX standard - * (3.3.4.2, page 72,line 934). According to section 8.1, page 191, - * however, signal(3) itself is not required by POSIX.1. And POSIX is - * silent on whether it is required to restart signals. - * - * So. The present situation is, we use sigaction(2) with no - * guarantee of restart anywhere but on Linux and BSD. We could - * switch to signal(3) and collar Linux, BSD, and SVr4. Any way - * we slice it, System V UNIXes older than SVr4 will probably lose - * (this may include XENIX). - * - * This implementation will probably be changed to use signal(3) in - * the future. If nothing else, it's simpler... - */ - -#if USE_SIGTSTP -static void -tstp(int dummy GCC_UNUSED) -{ - sigset_t mask, omask; - sigaction_t act, oact; - -#ifdef SIGTTOU - int sigttou_blocked; -#endif - - T(("tstp() called")); - - /* - * The user may have changed the prog_mode tty bits, so save them. - * - * But first try to detect whether we still are in the foreground - * process group - if not, an interactive shell may already have - * taken ownership of the tty and modified the settings when our - * parent was stopped before us, and we would likely pick up the - * settings already modified by the shell. - */ - if (SP != 0 && !SP->_endwin) /* don't do this if we're not in curses */ -#if HAVE_TCGETPGRP - if (tcgetpgrp(STDIN_FILENO) == getpgrp()) -#endif - def_prog_mode(); - - /* - * Block window change and timer signals. The latter - * is because applications use timers to decide when - * to repaint the screen. - */ - (void) sigemptyset(&mask); - (void) sigaddset(&mask, SIGALRM); -#if USE_SIGWINCH - (void) sigaddset(&mask, SIGWINCH); -#endif - (void) sigprocmask(SIG_BLOCK, &mask, &omask); - -#ifdef SIGTTOU - sigttou_blocked = sigismember(&omask, SIGTTOU); - if (!sigttou_blocked) { - (void) sigemptyset(&mask); - (void) sigaddset(&mask, SIGTTOU); - (void) sigprocmask(SIG_BLOCK, &mask, NULL); - } -#endif - - /* - * End window mode, which also resets the terminal state to the - * original (pre-curses) modes. - */ - endwin(); - - /* Unblock SIGTSTP. */ - (void) sigemptyset(&mask); - (void) sigaddset(&mask, SIGTSTP); -#ifdef SIGTTOU - if (!sigttou_blocked) { - /* Unblock this too if it wasn't blocked on entry */ - (void) sigaddset(&mask, SIGTTOU); - } -#endif - (void) sigprocmask(SIG_UNBLOCK, &mask, NULL); - - /* Now we want to resend SIGSTP to this process and suspend it */ - act.sa_handler = SIG_DFL; - sigemptyset(&act.sa_mask); - act.sa_flags = 0; -#ifdef SA_RESTART - act.sa_flags |= SA_RESTART; -#endif /* SA_RESTART */ - sigaction(SIGTSTP, &act, &oact); - kill(getpid(), SIGTSTP); - - /* Process gets suspended...time passes...process resumes */ - - T(("SIGCONT received")); - sigaction(SIGTSTP, &oact, NULL); - flushinp(); - - /* - * If the user modified the tty state while suspended, he wants - * those changes to stick. So save the new "default" terminal state. - */ - def_shell_mode(); - - /* - * This relies on the fact that doupdate() will restore the - * program-mode tty state, and issue enter_ca_mode if need be. - */ - doupdate(); - - /* Reset the signals. */ - (void) sigprocmask(SIG_SETMASK, &omask, NULL); -} -#endif /* USE_SIGTSTP */ - -static void -cleanup(int sig) -{ - static int nested; - - /* - * Actually, doing any sort of I/O from within an signal handler is - * "unsafe". But we'll _try_ to clean up the screen and terminal - * settings on the way out. - */ - if (!nested++ - && (sig == SIGINT - || sig == SIGQUIT)) { -#if HAVE_SIGACTION || HAVE_SIGVEC - sigaction_t act; - sigemptyset(&act.sa_mask); - act.sa_flags = 0; - act.sa_handler = SIG_IGN; - if (sigaction(sig, &act, NULL) == 0) -#else - if (signal(sig, SIG_IGN) != SIG_ERR) -#endif - { - SCREEN *scan = _nc_screen_chain; - while (scan) { - if (SP != 0 - && SP->_ofp != 0 - && isatty(fileno(SP->_ofp))) { - SP->_cleanup = TRUE; - SP->_outch = _nc_outch; - } - set_term(scan); - endwin(); - if (SP) - SP->_endwin = FALSE; /* in case we have an atexit! */ - scan = scan->_next_screen; - } - } - } - exit(EXIT_FAILURE); -} - -#if USE_SIGWINCH -static void -sigwinch(int sig GCC_UNUSED) -{ - SCREEN *scan = _nc_screen_chain; - while (scan) { - scan->_sig_winch = TRUE; - scan = scan->_next_screen; - } -} -#endif /* USE_SIGWINCH */ - -/* - * If the given signal is still in its default state, set it to the given - * handler. - */ -static int -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, 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, &new_act, NULL); - result = TRUE; - } else { - result = FALSE; - } -#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); - result = TRUE; - } else { - signal(sig, ohandler); - 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 - * initialize the signal catchers, and thereafter when spawning a shell (and - * returning) to disable/enable the SIGTSTP (i.e., ^Z) catcher. - * - * If the application has already set one of the signals, we'll not modify it - * (during initialization). - * - * 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. - */ -NCURSES_EXPORT(void) -_nc_signal_handler(bool enable) -{ - 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; -#endif /* SA_RESTART */ - act.sa_handler = tstp; - (void) sigaction(SIGTSTP, &act, NULL); - } else { - ignore_tstp = TRUE; - } - } - } -#endif /* !USE_SIGTSTP */ - - if (!initialized) { - if (enable) { - CatchIfDefault(SIGINT, cleanup); - CatchIfDefault(SIGTERM, cleanup); -#if USE_SIGWINCH - CatchIfDefault(SIGWINCH, sigwinch); -#endif - initialized = TRUE; - } - } - returnVoid; -} |