/* signals.c -- signal handling support for readline. */
/* Copyright (C) 1987-2009 Free Software Foundation, Inc.
This file is part of the GNU Readline Library (Readline), a library
for reading lines of text with interactive input and history editing.
Readline 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 3 of the License, or
(at your option) any later version.
Readline 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.
You should have received a copy of the GNU General Public License
along with Readline. If not, see <http://www.gnu.org/licenses/>.
*/
#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 */
/* Some standard library routines. */
#include "readline.h"
#include "history.h"
#include "rlprivate.h"
#if defined (HANDLE_SIGNALS)
#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 */
#ifndef SA_RESTART
# define SA_RESTART 0
#endif
static SigHandler *rl_set_sighandler PARAMS((int, SigHandler *, sighandler_cxt *));
static void rl_maybe_set_sighandler PARAMS((int, SigHandler *, sighandler_cxt *));
static RETSIGTYPE rl_signal_handler PARAMS((int));
static RETSIGTYPE _rl_handle_signal PARAMS((int));
/* 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;
#else
int rl_catch_sigwinch = 0; /* for the readline state struct in readline.c */
#endif
/* Private variables. */
int _rl_interrupt_immediately = 0;
int volatile _rl_caught_signal = 0; /* should be sig_atomic_t, but that requires including <signal.h> everywhere */
/* If non-zero, print characters corresponding to received signals as long as
the user has indicated his desire to do so (_rl_echo_control_chars). */
int _rl_echoctl = 0;
int _rl_intr_char = 0;
int _rl_quit_char = 0;
int _rl_susp_char = 0;
static int signals_set_flag;
static int sigwinch_set_flag;
/* **************************************************************** */
/* */
/* 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. */
/* Called from RL_CHECK_SIGNALS() macro */
RETSIGTYPE
_rl_signal_handler (sig)
int sig;
{
_rl_caught_signal = 0; /* XXX */
_rl_handle_signal (sig);
SIGHANDLER_RETURN;
}
static RETSIGTYPE
rl_signal_handler (sig)
int sig;
{
if (_rl_interrupt_immediately || RL_ISSTATE(RL_STATE_CALLBACK))
{
_rl_interrupt_immediately = 0;
_rl_handle_signal (sig);
}
else
_rl_caught_signal = sig;
SIGHANDLER_RETURN;
}
static RETSIGTYPE
_rl_handle_signal (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 defined (SIGALRM)
if (sig == SIGINT || sig == SIGALRM)
# else
if (sig == SIGINT)
# endif
rl_set_sighandler (sig, SIG_IGN, &dummy_cxt);
#endif /* !HAVE_BSD_SIGNALS && !HAVE_POSIX_SIGNALS */
switch (sig)
{
case SIGINT:
_rl_reset_completion_state ();
rl_free_line_state ();
/* FALLTHROUGH */
case SIGTERM:
#if defined (SIGTSTP)
case SIGTSTP:
case SIGTTOU:
case SIGTTIN:
#endif /* SIGTSTP */
#if defined (SIGALRM)
case SIGALRM:
#endif
#if defined (SIGQUIT)
case SIGQUIT:
#endif
rl_echo_signal_char (sig);
rl_cleanup_after_signal ();
#if defined (HAVE_POSIX_SIGNALS)
sigemptyset (&set);
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
#if defined (HAVE_KILL)
kill (getpid (), sig);
#else
raise (sig); /* assume we have raise */
#endif
/* 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;
# if defined (SIGWINCH)
act.sa_flags = (sig == SIGWINCH) ? SA_RESTART : 0;
# else
act.sa_flags = 0;
# endif /* 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 defined (HAVE_POSIX_SIGNALS)
static int sigmask_set = 0;
static sigset_t bset, oset;
#endif
#if defined (HAVE_POSIX_SIGNALS)
if (rl_catch_signals && sigmask_set == 0)
{
sigemptyset (&bset);
sigaddset (&bset, SIGINT);
sigaddset (&bset, SIGTERM);
#if defined (SIGQUIT)
sigaddset (&bset, SIGQUIT);
#endif
#if defined (SIGALRM)
sigaddset (&bset, SIGALRM);
#endif
#if defined (SIGTSTP)
sigaddset (&bset, SIGTSTP);
#endif
#if defined (SIGTTIN)
sigaddset (&bset, SIGTTIN);
#endif
#if defined (SIGTTOU)
sigaddset (&bset, SIGTTOU);
#endif
sigmask_set = 1;
}
#endif /* HAVE_POSIX_SIGNALS */
if (rl_catch_signals && signals_set_flag == 0)
{
#if defined (HAVE_POSIX_SIGNALS)
sigemptyset (&oset);
sigprocmask (SIG_BLOCK, &bset, &oset);
#endif
rl_maybe_set_sighandler (SIGINT, rl_signal_handler, &old_int);
rl_maybe_set_sighandler (SIGTERM, rl_signal_handler, &old_term);
#if defined (SIGQUIT)
rl_maybe_set_sighandler (SIGQUIT, rl_signal_handler, &old_quit);
#endif
#if defined (SIGALRM)
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 */
#endif /* SIGALRM */
#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 (HAVE_POSIX_SIGNALS)
sigprocmask (SIG_SETMASK, &oset, (sigset_t *)NULL);
#endif
}
#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);
#if defined (SIGQUIT)
rl_sigaction (SIGQUIT, &old_quit, &dummy);
#endif
#if defined (SIGALRM)
rl_sigaction (SIGALRM, &old_alrm, &dummy);
#endif
#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 ();
if (rl_deprep_term_function)
(*rl_deprep_term_function) ();
rl_clear_pending_input ();
rl_clear_signals ();
}
/* Reset the terminal and readline state after a signal handler returns. */
void
rl_reset_after_signal ()
{
if (rl_prep_term_function)
(*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_reset_argument ();
}
#endif /* HANDLE_SIGNALS */
/* **************************************************************** */
/* */
/* SIGINT Management */
/* */
/* **************************************************************** */
#if defined (HAVE_POSIX_SIGNALS)
static sigset_t sigint_set, sigint_oset;
static sigset_t sigwinch_set, sigwinch_oset;
#else /* !HAVE_POSIX_SIGNALS */
# if defined (HAVE_BSD_SIGNALS)
static int sigint_oldmask;
static int sigwinch_oldmask;
# endif /* HAVE_BSD_SIGNALS */
#endif /* !HAVE_POSIX_SIGNALS */
static int sigint_blocked;
static int sigwinch_blocked;
/* Cause SIGINT to not be delivered until the corresponding call to
release_sigint(). */
void
_rl_block_sigint ()
{
if (sigint_blocked)
return;
#if defined (HAVE_POSIX_SIGNALS)
sigemptyset (&sigint_set);
sigemptyset (&sigint_oset);
sigaddset (&sigint_set, SIGINT);
sigprocmask (SIG_BLOCK, &sigint_set, &sigint_oset);
#else /* !HAVE_POSIX_SIGNALS */
# if defined (HAVE_BSD_SIGNALS)
sigint_oldmask = sigblock (sigmask (SIGINT));
# else /* !HAVE_BSD_SIGNALS */
# if defined (HAVE_USG_SIGHOLD)
sighold (SIGINT);
# endif /* HAVE_USG_SIGHOLD */
# endif /* !HAVE_BSD_SIGNALS */
#endif /* !HAVE_POSIX_SIGNALS */
sigint_blocked = 1;
}
/* Allow SIGINT to be delivered. */
void
_rl_release_sigint ()
{
if (sigint_blocked == 0)
return;
#if defined (HAVE_POSIX_SIGNALS)
sigprocmask (SIG_SETMASK, &sigint_oset, (sigset_t *)NULL);
#else
# if defined (HAVE_BSD_SIGNALS)
sigsetmask (sigint_oldmask);
# else /* !HAVE_BSD_SIGNALS */
# if defined (HAVE_USG_SIGHOLD)
sigrelse (SIGINT);
# endif /* HAVE_USG_SIGHOLD */
# endif /* !HAVE_BSD_SIGNALS */
#endif /* !HAVE_POSIX_SIGNALS */
sigint_blocked = 0;
}
/* Cause SIGWINCH to not be delivered until the corresponding call to
release_sigwinch(). */
void
_rl_block_sigwinch ()
{
if (sigwinch_blocked)
return;
#if defined (HAVE_POSIX_SIGNALS)
sigemptyset (&sigwinch_set);
sigemptyset (&sigwinch_oset);
sigaddset (&sigwinch_set, SIGWINCH);
sigprocmask (SIG_BLOCK, &sigwinch_set, &sigwinch_oset);
#else /* !HAVE_POSIX_SIGNALS */
# if defined (HAVE_BSD_SIGNALS)
sigwinch_oldmask = sigblock (sigmask (SIGWINCH));
# else /* !HAVE_BSD_SIGNALS */
# if defined (HAVE_USG_SIGHOLD)
sighold (SIGWINCH);
# endif /* HAVE_USG_SIGHOLD */
# endif /* !HAVE_BSD_SIGNALS */
#endif /* !HAVE_POSIX_SIGNALS */
sigwinch_blocked = 1;
}
/* Allow SIGWINCH to be delivered. */
void
_rl_release_sigwinch ()
{
if (sigwinch_blocked == 0)
return;
#if defined (HAVE_POSIX_SIGNALS)
sigprocmask (SIG_SETMASK, &sigwinch_oset, (sigset_t *)NULL);
#else
# if defined (HAVE_BSD_SIGNALS)
sigsetmask (sigwinch_oldmask);
# else /* !HAVE_BSD_SIGNALS */
# if defined (HAVE_USG_SIGHOLD)
sigrelse (SIGWINCH);
# endif /* HAVE_USG_SIGHOLD */
# endif /* !HAVE_BSD_SIGNALS */
#endif /* !HAVE_POSIX_SIGNALS */
sigwinch_blocked = 0;
}
/* **************************************************************** */
/* */
/* Echoing special control characters */
/* */
/* **************************************************************** */
void
rl_echo_signal_char (sig)
int sig;
{
char cstr[3];
int cslen, c;
if (_rl_echoctl == 0 || _rl_echo_control_chars == 0)
return;
switch (sig)
{
case SIGINT: c = _rl_intr_char; break;
#if defined (SIGQUIT)
case SIGQUIT: c = _rl_quit_char; break;
#endif
#if defined (SIGTSTP)
case SIGTSTP: c = _rl_susp_char; break;
#endif
default: return;
}
if (CTRL_CHAR (c) || c == RUBOUT)
{
cstr[0] = '^';
cstr[1] = CTRL_CHAR (c) ? UNCTRL (c) : '?';
cstr[cslen = 2] = '\0';
}
else
{
cstr[0] = c;
cstr[cslen = 1] = '\0';
}
_rl_output_some_chars (cstr, cslen);
}