467 lines
12 KiB
C
467 lines
12 KiB
C
/* signals.c -- signal handling support for readline. */
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/* Copyright (C) 1987-2005 Free Software Foundation, Inc.
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This file is part of the GNU Readline Library, a library for
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reading lines of text with interactive input and history editing.
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The GNU Readline Library is free software; you can redistribute it
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and/or modify it under the terms of the GNU General Public License
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as published by the Free Software Foundation; either version 2, or
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(at your option) any later version.
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The GNU Readline Library is distributed in the hope that it will be
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useful, but WITHOUT ANY WARRANTY; without even the implied warranty
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of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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The GNU General Public License is often shipped with GNU software, and
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is generally kept in a file called COPYING or LICENSE. If you do not
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have a copy of the license, write to the Free Software Foundation,
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59 Temple Place, Suite 330, Boston, MA 02111 USA. */
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#define READLINE_LIBRARY
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#if defined (HAVE_CONFIG_H)
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# include <config.h>
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#endif
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#include <stdio.h> /* Just for NULL. Yuck. */
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#include <sys/types.h>
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#include <signal.h>
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#if defined (HAVE_UNISTD_H)
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# include <unistd.h>
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#endif /* HAVE_UNISTD_H */
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/* System-specific feature definitions and include files. */
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#include "rldefs.h"
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#if defined (GWINSZ_IN_SYS_IOCTL)
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# include <sys/ioctl.h>
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#endif /* GWINSZ_IN_SYS_IOCTL */
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#if defined (HANDLE_SIGNALS)
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/* Some standard library routines. */
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#include "readline.h"
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#include "history.h"
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#include "rlprivate.h"
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#if !defined (RETSIGTYPE)
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# if defined (VOID_SIGHANDLER)
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# define RETSIGTYPE void
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# else
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# define RETSIGTYPE int
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# endif /* !VOID_SIGHANDLER */
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#endif /* !RETSIGTYPE */
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#if defined (VOID_SIGHANDLER)
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# define SIGHANDLER_RETURN return
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#else
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# define SIGHANDLER_RETURN return (0)
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#endif
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/* This typedef is equivalent to the one for Function; it allows us
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to say SigHandler *foo = signal (SIGKILL, SIG_IGN); */
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typedef RETSIGTYPE SigHandler ();
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#if defined (HAVE_POSIX_SIGNALS)
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typedef struct sigaction sighandler_cxt;
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# define rl_sigaction(s, nh, oh) sigaction(s, nh, oh)
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#else
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typedef struct { SigHandler *sa_handler; int sa_mask, sa_flags; } sighandler_cxt;
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# define sigemptyset(m)
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#endif /* !HAVE_POSIX_SIGNALS */
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#ifndef SA_RESTART
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# define SA_RESTART 0
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#endif
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static SigHandler *rl_set_sighandler PARAMS((int, SigHandler *, sighandler_cxt *));
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static void rl_maybe_set_sighandler PARAMS((int, SigHandler *, sighandler_cxt *));
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/* Exported variables for use by applications. */
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/* If non-zero, readline will install its own signal handlers for
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SIGINT, SIGTERM, SIGQUIT, SIGALRM, SIGTSTP, SIGTTIN, and SIGTTOU. */
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int rl_catch_signals = 1;
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/* If non-zero, readline will install a signal handler for SIGWINCH. */
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#ifdef SIGWINCH
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int rl_catch_sigwinch = 1;
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#else
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int rl_catch_sigwinch = 0; /* for the readline state struct in readline.c */
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#endif
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static int signals_set_flag;
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static int sigwinch_set_flag;
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/* **************************************************************** */
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/* */
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/* Signal Handling */
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/* */
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/* **************************************************************** */
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static sighandler_cxt old_int, old_term, old_alrm, old_quit;
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#if defined (SIGTSTP)
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static sighandler_cxt old_tstp, old_ttou, old_ttin;
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#endif
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#if defined (SIGWINCH)
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static sighandler_cxt old_winch;
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#endif
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/* Readline signal handler functions. */
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static RETSIGTYPE
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rl_signal_handler (sig)
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int sig;
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{
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#if defined (HAVE_POSIX_SIGNALS)
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sigset_t set;
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#else /* !HAVE_POSIX_SIGNALS */
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# if defined (HAVE_BSD_SIGNALS)
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long omask;
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# else /* !HAVE_BSD_SIGNALS */
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sighandler_cxt dummy_cxt; /* needed for rl_set_sighandler call */
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# endif /* !HAVE_BSD_SIGNALS */
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#endif /* !HAVE_POSIX_SIGNALS */
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RL_SETSTATE(RL_STATE_SIGHANDLER);
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#if !defined (HAVE_BSD_SIGNALS) && !defined (HAVE_POSIX_SIGNALS)
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/* Since the signal will not be blocked while we are in the signal
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handler, ignore it until rl_clear_signals resets the catcher. */
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# if defined (SIGALRM)
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if (sig == SIGINT || sig == SIGALRM)
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# else
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if (sig == SIGINT)
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# endif
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rl_set_sighandler (sig, SIG_IGN, &dummy_cxt);
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#endif /* !HAVE_BSD_SIGNALS && !HAVE_POSIX_SIGNALS */
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switch (sig)
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{
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case SIGINT:
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rl_free_line_state ();
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/* FALLTHROUGH */
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case SIGTERM:
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#if defined (SIGTSTP)
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case SIGTSTP:
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case SIGTTOU:
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case SIGTTIN:
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#endif /* SIGTSTP */
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#if defined (SIGALRM)
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case SIGALRM:
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#endif
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#if defined (SIGQUIT)
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case SIGQUIT:
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#endif
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rl_cleanup_after_signal ();
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#if defined (HAVE_POSIX_SIGNALS)
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sigemptyset (&set);
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sigprocmask (SIG_BLOCK, (sigset_t *)NULL, &set);
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sigdelset (&set, sig);
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#else /* !HAVE_POSIX_SIGNALS */
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# if defined (HAVE_BSD_SIGNALS)
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omask = sigblock (0);
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# endif /* HAVE_BSD_SIGNALS */
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#endif /* !HAVE_POSIX_SIGNALS */
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#if defined (__EMX__)
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signal (sig, SIG_ACK);
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#endif
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#if defined (HAVE_KILL)
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kill (getpid (), sig);
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#else
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raise (sig); /* assume we have raise */
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#endif
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/* Let the signal that we just sent through. */
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#if defined (HAVE_POSIX_SIGNALS)
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sigprocmask (SIG_SETMASK, &set, (sigset_t *)NULL);
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#else /* !HAVE_POSIX_SIGNALS */
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# if defined (HAVE_BSD_SIGNALS)
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sigsetmask (omask & ~(sigmask (sig)));
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# endif /* HAVE_BSD_SIGNALS */
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#endif /* !HAVE_POSIX_SIGNALS */
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rl_reset_after_signal ();
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}
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RL_UNSETSTATE(RL_STATE_SIGHANDLER);
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SIGHANDLER_RETURN;
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}
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#if defined (SIGWINCH)
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static RETSIGTYPE
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rl_sigwinch_handler (sig)
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int sig;
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{
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SigHandler *oh;
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#if defined (MUST_REINSTALL_SIGHANDLERS)
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sighandler_cxt dummy_winch;
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/* We don't want to change old_winch -- it holds the state of SIGWINCH
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disposition set by the calling application. We need this state
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because we call the application's SIGWINCH handler after updating
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our own idea of the screen size. */
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rl_set_sighandler (SIGWINCH, rl_sigwinch_handler, &dummy_winch);
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#endif
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RL_SETSTATE(RL_STATE_SIGHANDLER);
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rl_resize_terminal ();
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/* If another sigwinch handler has been installed, call it. */
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oh = (SigHandler *)old_winch.sa_handler;
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if (oh && oh != (SigHandler *)SIG_IGN && oh != (SigHandler *)SIG_DFL)
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(*oh) (sig);
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RL_UNSETSTATE(RL_STATE_SIGHANDLER);
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SIGHANDLER_RETURN;
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}
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#endif /* SIGWINCH */
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/* Functions to manage signal handling. */
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#if !defined (HAVE_POSIX_SIGNALS)
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static int
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rl_sigaction (sig, nh, oh)
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int sig;
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sighandler_cxt *nh, *oh;
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{
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oh->sa_handler = signal (sig, nh->sa_handler);
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return 0;
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}
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#endif /* !HAVE_POSIX_SIGNALS */
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/* Set up a readline-specific signal handler, saving the old signal
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information in OHANDLER. Return the old signal handler, like
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signal(). */
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static SigHandler *
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rl_set_sighandler (sig, handler, ohandler)
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int sig;
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SigHandler *handler;
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sighandler_cxt *ohandler;
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{
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sighandler_cxt old_handler;
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#if defined (HAVE_POSIX_SIGNALS)
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struct sigaction act;
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act.sa_handler = handler;
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act.sa_flags = (sig == SIGWINCH) ? SA_RESTART : 0;
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sigemptyset (&act.sa_mask);
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sigemptyset (&ohandler->sa_mask);
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sigaction (sig, &act, &old_handler);
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#else
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old_handler.sa_handler = (SigHandler *)signal (sig, handler);
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#endif /* !HAVE_POSIX_SIGNALS */
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/* XXX -- assume we have memcpy */
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/* If rl_set_signals is called twice in a row, don't set the old handler to
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rl_signal_handler, because that would cause infinite recursion. */
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if (handler != rl_signal_handler || old_handler.sa_handler != rl_signal_handler)
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memcpy (ohandler, &old_handler, sizeof (sighandler_cxt));
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return (ohandler->sa_handler);
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}
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static void
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rl_maybe_set_sighandler (sig, handler, ohandler)
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int sig;
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SigHandler *handler;
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sighandler_cxt *ohandler;
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{
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sighandler_cxt dummy;
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SigHandler *oh;
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sigemptyset (&dummy.sa_mask);
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oh = rl_set_sighandler (sig, handler, ohandler);
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if (oh == (SigHandler *)SIG_IGN)
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rl_sigaction (sig, ohandler, &dummy);
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}
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int
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rl_set_signals ()
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{
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sighandler_cxt dummy;
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SigHandler *oh;
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#if defined (HAVE_POSIX_SIGNALS)
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static int sigmask_set = 0;
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static sigset_t bset, oset;
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#endif
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#if defined (HAVE_POSIX_SIGNALS)
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if (rl_catch_signals && sigmask_set == 0)
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{
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sigemptyset (&bset);
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sigaddset (&bset, SIGINT);
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sigaddset (&bset, SIGINT);
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#if defined (SIGQUIT)
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sigaddset (&bset, SIGQUIT);
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#endif
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#if defined (SIGALRM)
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sigaddset (&bset, SIGALRM);
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#endif
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#if defined (SIGTSTP)
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sigaddset (&bset, SIGTSTP);
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#endif
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#if defined (SIGTTIN)
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sigaddset (&bset, SIGTTIN);
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#endif
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#if defined (SIGTTOU)
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sigaddset (&bset, SIGTTOU);
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#endif
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sigmask_set = 1;
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}
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#endif /* HAVE_POSIX_SIGNALS */
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if (rl_catch_signals && signals_set_flag == 0)
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{
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#if defined (HAVE_POSIX_SIGNALS)
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sigemptyset (&oset);
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sigprocmask (SIG_BLOCK, &bset, &oset);
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#endif
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rl_maybe_set_sighandler (SIGINT, rl_signal_handler, &old_int);
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rl_maybe_set_sighandler (SIGTERM, rl_signal_handler, &old_term);
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#if defined (SIGQUIT)
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rl_maybe_set_sighandler (SIGQUIT, rl_signal_handler, &old_quit);
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#endif
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#if defined (SIGALRM)
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oh = rl_set_sighandler (SIGALRM, rl_signal_handler, &old_alrm);
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if (oh == (SigHandler *)SIG_IGN)
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rl_sigaction (SIGALRM, &old_alrm, &dummy);
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#if defined (HAVE_POSIX_SIGNALS) && defined (SA_RESTART)
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/* If the application using readline has already installed a signal
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handler with SA_RESTART, SIGALRM will cause reads to be restarted
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automatically, so readline should just get out of the way. Since
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we tested for SIG_IGN above, we can just test for SIG_DFL here. */
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if (oh != (SigHandler *)SIG_DFL && (old_alrm.sa_flags & SA_RESTART))
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rl_sigaction (SIGALRM, &old_alrm, &dummy);
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#endif /* HAVE_POSIX_SIGNALS */
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#endif /* SIGALRM */
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#if defined (SIGTSTP)
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rl_maybe_set_sighandler (SIGTSTP, rl_signal_handler, &old_tstp);
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#endif /* SIGTSTP */
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#if defined (SIGTTOU)
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rl_maybe_set_sighandler (SIGTTOU, rl_signal_handler, &old_ttou);
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#endif /* SIGTTOU */
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#if defined (SIGTTIN)
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rl_maybe_set_sighandler (SIGTTIN, rl_signal_handler, &old_ttin);
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#endif /* SIGTTIN */
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signals_set_flag = 1;
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#if defined (HAVE_POSIX_SIGNALS)
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sigprocmask (SIG_SETMASK, &oset, (sigset_t *)NULL);
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#endif
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}
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#if defined (SIGWINCH)
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if (rl_catch_sigwinch && sigwinch_set_flag == 0)
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{
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rl_maybe_set_sighandler (SIGWINCH, rl_sigwinch_handler, &old_winch);
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sigwinch_set_flag = 1;
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}
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#endif /* SIGWINCH */
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return 0;
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}
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int
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rl_clear_signals ()
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{
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sighandler_cxt dummy;
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if (rl_catch_signals && signals_set_flag == 1)
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{
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sigemptyset (&dummy.sa_mask);
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rl_sigaction (SIGINT, &old_int, &dummy);
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rl_sigaction (SIGTERM, &old_term, &dummy);
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#if defined (SIGQUIT)
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rl_sigaction (SIGQUIT, &old_quit, &dummy);
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#endif
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#if defined (SIGALRM)
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rl_sigaction (SIGALRM, &old_alrm, &dummy);
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#endif
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#if defined (SIGTSTP)
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rl_sigaction (SIGTSTP, &old_tstp, &dummy);
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#endif /* SIGTSTP */
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#if defined (SIGTTOU)
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rl_sigaction (SIGTTOU, &old_ttou, &dummy);
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#endif /* SIGTTOU */
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#if defined (SIGTTIN)
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rl_sigaction (SIGTTIN, &old_ttin, &dummy);
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#endif /* SIGTTIN */
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signals_set_flag = 0;
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}
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#if defined (SIGWINCH)
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if (rl_catch_sigwinch && sigwinch_set_flag == 1)
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{
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sigemptyset (&dummy.sa_mask);
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rl_sigaction (SIGWINCH, &old_winch, &dummy);
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sigwinch_set_flag = 0;
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}
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#endif
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return 0;
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}
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/* Clean up the terminal and readline state after catching a signal, before
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resending it to the calling application. */
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void
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rl_cleanup_after_signal ()
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{
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_rl_clean_up_for_exit ();
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if (rl_deprep_term_function)
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(*rl_deprep_term_function) ();
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rl_clear_pending_input ();
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rl_clear_signals ();
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}
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/* Reset the terminal and readline state after a signal handler returns. */
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void
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rl_reset_after_signal ()
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{
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if (rl_prep_term_function)
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(*rl_prep_term_function) (_rl_meta_flag);
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rl_set_signals ();
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}
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/* Free up the readline variable line state for the current line (undo list,
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any partial history entry, any keyboard macros in progress, and any
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numeric arguments in process) after catching a signal, before calling
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rl_cleanup_after_signal(). */
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void
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rl_free_line_state ()
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{
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register HIST_ENTRY *entry;
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rl_free_undo_list ();
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entry = current_history ();
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if (entry)
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entry->data = (char *)NULL;
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_rl_kill_kbd_macro ();
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rl_clear_message ();
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_rl_reset_argument ();
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}
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#endif /* HANDLE_SIGNALS */
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