/* signals.c -- signal handling support for readline. */ /* Copyright (C) 1987, 1989, 1992 Free Software Foundation, Inc. This file is part of the GNU Readline Library, a library for reading lines of text with interactive input and history editing. The GNU Readline Library is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. The GNU Readline Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. The GNU General Public License is often shipped with GNU software, and is generally kept in a file called COPYING or LICENSE. If you do not have a copy of the license, write to the Free Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. */ #define READLINE_LIBRARY #if defined (HAVE_CONFIG_H) # include <config.h> #endif #include <stdio.h> /* Just for NULL. Yuck. */ #include <sys/types.h> #include <signal.h> #if defined (HAVE_UNISTD_H) # include <unistd.h> #endif /* HAVE_UNISTD_H */ /* System-specific feature definitions and include files. */ #include "rldefs.h" #if defined (GWINSZ_IN_SYS_IOCTL) # include <sys/ioctl.h> #endif /* GWINSZ_IN_SYS_IOCTL */ #if defined (HANDLE_SIGNALS) /* Some standard library routines. */ #include "readline.h" #include "history.h" #include "rlprivate.h" #if !defined (RETSIGTYPE) # if defined (VOID_SIGHANDLER) # define RETSIGTYPE void # else # define RETSIGTYPE int # endif /* !VOID_SIGHANDLER */ #endif /* !RETSIGTYPE */ #if defined (VOID_SIGHANDLER) # define SIGHANDLER_RETURN return #else # define SIGHANDLER_RETURN return (0) #endif /* This typedef is equivalent to the one for Function; it allows us to say SigHandler *foo = signal (SIGKILL, SIG_IGN); */ typedef RETSIGTYPE SigHandler (); #if defined (HAVE_POSIX_SIGNALS) typedef struct sigaction sighandler_cxt; # define rl_sigaction(s, nh, oh) sigaction(s, nh, oh) #else typedef struct { SigHandler *sa_handler; int sa_mask, sa_flags; } sighandler_cxt; # define sigemptyset(m) #endif /* !HAVE_POSIX_SIGNALS */ static SigHandler *rl_set_sighandler PARAMS((int, SigHandler *, sighandler_cxt *)); static void rl_maybe_set_sighandler PARAMS((int, SigHandler *, sighandler_cxt *)); /* Exported variables for use by applications. */ /* If non-zero, readline will install its own signal handlers for SIGINT, SIGTERM, SIGQUIT, SIGALRM, SIGTSTP, SIGTTIN, and SIGTTOU. */ int rl_catch_signals = 1; /* If non-zero, readline will install a signal handler for SIGWINCH. */ #ifdef SIGWINCH int rl_catch_sigwinch = 1; #endif static int signals_set_flag; #ifdef SIGWINCH static int sigwinch_set_flag; #endif /* **************************************************************** */ /* */ /* Signal Handling */ /* */ /* **************************************************************** */ static sighandler_cxt old_int, old_term, old_alrm, old_quit; #if defined (SIGTSTP) static sighandler_cxt old_tstp, old_ttou, old_ttin; #endif #if defined (SIGWINCH) static sighandler_cxt old_winch; #endif /* Readline signal handler functions. */ static RETSIGTYPE rl_signal_handler (sig) int sig; { #if defined (HAVE_POSIX_SIGNALS) sigset_t set; #else /* !HAVE_POSIX_SIGNALS */ # if defined (HAVE_BSD_SIGNALS) long omask; # else /* !HAVE_BSD_SIGNALS */ sighandler_cxt dummy_cxt; /* needed for rl_set_sighandler call */ # endif /* !HAVE_BSD_SIGNALS */ #endif /* !HAVE_POSIX_SIGNALS */ RL_SETSTATE(RL_STATE_SIGHANDLER); #if !defined (HAVE_BSD_SIGNALS) && !defined (HAVE_POSIX_SIGNALS) /* Since the signal will not be blocked while we are in the signal handler, ignore it until rl_clear_signals resets the catcher. */ if (sig == SIGINT || sig == SIGALRM) rl_set_sighandler (sig, SIG_IGN, &dummy_cxt); #endif /* !HAVE_BSD_SIGNALS && !HAVE_POSIX_SIGNALS */ switch (sig) { case SIGINT: rl_free_line_state (); /* FALLTHROUGH */ #if defined (SIGTSTP) case SIGTSTP: case SIGTTOU: case SIGTTIN: #endif /* SIGTSTP */ case SIGALRM: case SIGTERM: case SIGQUIT: rl_cleanup_after_signal (); #if defined (HAVE_POSIX_SIGNALS) sigprocmask (SIG_BLOCK, (sigset_t *)NULL, &set); sigdelset (&set, sig); #else /* !HAVE_POSIX_SIGNALS */ # if defined (HAVE_BSD_SIGNALS) omask = sigblock (0); # endif /* HAVE_BSD_SIGNALS */ #endif /* !HAVE_POSIX_SIGNALS */ #if defined (__EMX__) signal (sig, SIG_ACK); #endif kill (getpid (), sig); /* Let the signal that we just sent through. */ #if defined (HAVE_POSIX_SIGNALS) sigprocmask (SIG_SETMASK, &set, (sigset_t *)NULL); #else /* !HAVE_POSIX_SIGNALS */ # if defined (HAVE_BSD_SIGNALS) sigsetmask (omask & ~(sigmask (sig))); # endif /* HAVE_BSD_SIGNALS */ #endif /* !HAVE_POSIX_SIGNALS */ rl_reset_after_signal (); } RL_UNSETSTATE(RL_STATE_SIGHANDLER); SIGHANDLER_RETURN; } #if defined (SIGWINCH) static RETSIGTYPE rl_sigwinch_handler (sig) int sig; { SigHandler *oh; #if defined (MUST_REINSTALL_SIGHANDLERS) sighandler_cxt dummy_winch; /* We don't want to change old_winch -- it holds the state of SIGWINCH disposition set by the calling application. We need this state because we call the application's SIGWINCH handler after updating our own idea of the screen size. */ rl_set_sighandler (SIGWINCH, rl_sigwinch_handler, &dummy_winch); #endif RL_SETSTATE(RL_STATE_SIGHANDLER); rl_resize_terminal (); /* If another sigwinch handler has been installed, call it. */ oh = (SigHandler *)old_winch.sa_handler; if (oh && oh != (SigHandler *)SIG_IGN && oh != (SigHandler *)SIG_DFL) (*oh) (sig); RL_UNSETSTATE(RL_STATE_SIGHANDLER); SIGHANDLER_RETURN; } #endif /* SIGWINCH */ /* Functions to manage signal handling. */ #if !defined (HAVE_POSIX_SIGNALS) static int rl_sigaction (sig, nh, oh) int sig; sighandler_cxt *nh, *oh; { oh->sa_handler = signal (sig, nh->sa_handler); return 0; } #endif /* !HAVE_POSIX_SIGNALS */ /* Set up a readline-specific signal handler, saving the old signal information in OHANDLER. Return the old signal handler, like signal(). */ static SigHandler * rl_set_sighandler (sig, handler, ohandler) int sig; SigHandler *handler; sighandler_cxt *ohandler; { sighandler_cxt old_handler; #if defined (HAVE_POSIX_SIGNALS) struct sigaction act; act.sa_handler = handler; act.sa_flags = 0; /* XXX - should we set SA_RESTART for SIGWINCH? */ sigemptyset (&act.sa_mask); sigemptyset (&ohandler->sa_mask); sigaction (sig, &act, &old_handler); #else old_handler.sa_handler = (SigHandler *)signal (sig, handler); #endif /* !HAVE_POSIX_SIGNALS */ /* XXX -- assume we have memcpy */ /* If rl_set_signals is called twice in a row, don't set the old handler to rl_signal_handler, because that would cause infinite recursion. */ if (handler != rl_signal_handler || old_handler.sa_handler != rl_signal_handler) memcpy (ohandler, &old_handler, sizeof (sighandler_cxt)); return (ohandler->sa_handler); } static void rl_maybe_set_sighandler (sig, handler, ohandler) int sig; SigHandler *handler; sighandler_cxt *ohandler; { sighandler_cxt dummy; SigHandler *oh; sigemptyset (&dummy.sa_mask); oh = rl_set_sighandler (sig, handler, ohandler); if (oh == (SigHandler *)SIG_IGN) rl_sigaction (sig, ohandler, &dummy); } int rl_set_signals () { sighandler_cxt dummy; SigHandler *oh; if (rl_catch_signals && signals_set_flag == 0) { rl_maybe_set_sighandler (SIGINT, rl_signal_handler, &old_int); rl_maybe_set_sighandler (SIGTERM, rl_signal_handler, &old_term); rl_maybe_set_sighandler (SIGQUIT, rl_signal_handler, &old_quit); oh = rl_set_sighandler (SIGALRM, rl_signal_handler, &old_alrm); if (oh == (SigHandler *)SIG_IGN) rl_sigaction (SIGALRM, &old_alrm, &dummy); #if defined (HAVE_POSIX_SIGNALS) && defined (SA_RESTART) /* If the application using readline has already installed a signal handler with SA_RESTART, SIGALRM will cause reads to be restarted automatically, so readline should just get out of the way. Since we tested for SIG_IGN above, we can just test for SIG_DFL here. */ if (oh != (SigHandler *)SIG_DFL && (old_alrm.sa_flags & SA_RESTART)) rl_sigaction (SIGALRM, &old_alrm, &dummy); #endif /* HAVE_POSIX_SIGNALS */ #if defined (SIGTSTP) rl_maybe_set_sighandler (SIGTSTP, rl_signal_handler, &old_tstp); #endif /* SIGTSTP */ #if defined (SIGTTOU) rl_maybe_set_sighandler (SIGTTOU, rl_signal_handler, &old_ttou); #endif /* SIGTTOU */ #if defined (SIGTTIN) rl_maybe_set_sighandler (SIGTTIN, rl_signal_handler, &old_ttin); #endif /* SIGTTIN */ signals_set_flag = 1; } #if defined (SIGWINCH) if (rl_catch_sigwinch && sigwinch_set_flag == 0) { rl_maybe_set_sighandler (SIGWINCH, rl_sigwinch_handler, &old_winch); sigwinch_set_flag = 1; } #endif /* SIGWINCH */ return 0; } int rl_clear_signals () { sighandler_cxt dummy; if (rl_catch_signals && signals_set_flag == 1) { sigemptyset (&dummy.sa_mask); rl_sigaction (SIGINT, &old_int, &dummy); rl_sigaction (SIGTERM, &old_term, &dummy); rl_sigaction (SIGQUIT, &old_quit, &dummy); rl_sigaction (SIGALRM, &old_alrm, &dummy); #if defined (SIGTSTP) rl_sigaction (SIGTSTP, &old_tstp, &dummy); #endif /* SIGTSTP */ #if defined (SIGTTOU) rl_sigaction (SIGTTOU, &old_ttou, &dummy); #endif /* SIGTTOU */ #if defined (SIGTTIN) rl_sigaction (SIGTTIN, &old_ttin, &dummy); #endif /* SIGTTIN */ signals_set_flag = 0; } #if defined (SIGWINCH) if (rl_catch_sigwinch && sigwinch_set_flag == 1) { sigemptyset (&dummy.sa_mask); rl_sigaction (SIGWINCH, &old_winch, &dummy); sigwinch_set_flag = 0; } #endif return 0; } /* Clean up the terminal and readline state after catching a signal, before resending it to the calling application. */ void rl_cleanup_after_signal () { _rl_clean_up_for_exit (); (*rl_deprep_term_function) (); rl_clear_signals (); rl_clear_pending_input (); } /* Reset the terminal and readline state after a signal handler returns. */ void rl_reset_after_signal () { (*rl_prep_term_function) (_rl_meta_flag); rl_set_signals (); } /* Free up the readline variable line state for the current line (undo list, any partial history entry, any keyboard macros in progress, and any numeric arguments in process) after catching a signal, before calling rl_cleanup_after_signal(). */ void rl_free_line_state () { register HIST_ENTRY *entry; rl_free_undo_list (); entry = current_history (); if (entry) entry->data = (char *)NULL; _rl_kill_kbd_macro (); rl_clear_message (); _rl_init_argument (); } #endif /* HANDLE_SIGNALS */