freebsd-dev/contrib/libreadline/signals.c

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1997-01-04 22:09:20 +00:00
/* 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 1, 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,
675 Mass Ave, Cambridge, MA 02139, 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 (__GO32__)
# undef HANDLE_SIGNALS
#endif /* __GO32__ */
#if defined (HANDLE_SIGNALS)
/* Some standard library routines. */
#include "readline.h"
#include "history.h"
extern int readline_echoing_p;
extern int rl_pending_input;
extern int _rl_meta_flag;
extern void free_undo_list ();
extern void _rl_get_screen_size ();
extern void _rl_redisplay_after_sigwinch ();
extern void _rl_clean_up_for_exit ();
extern void _rl_kill_kbd_macro ();
extern void _rl_init_argument ();
extern void rl_deprep_terminal (), rl_prep_terminal ();
#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 equivalant to the one for Function; it allows us
to say SigHandler *foo = signal (SIGKILL, SIG_IGN); */
typedef RETSIGTYPE SigHandler ();
static SigHandler *rl_set_sighandler ();
/* **************************************************************** */
/* */
/* Signal Handling */
/* */
/* **************************************************************** */
#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; } sighandler_cxt;
# define sigemptyset(m)
#endif /* !HAVE_POSIX_SIGNALS */
static sighandler_cxt old_int, old_alrm;
#if !defined (SHELL)
static sighandler_cxt old_tstp, old_ttou, old_ttin, old_term;
#endif /* !SHELL */
#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;
# endif /* HAVE_BSD_SIGNALS */
#endif /* !HAVE_POSIX_SIGNALS */
#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, (sighandler_cxt *)NULL);
#endif /* !HAVE_BSD_SIGNALS && !HAVE_POSIX_SIGNALS */
switch (sig)
{
case SIGINT:
{
register HIST_ENTRY *entry;
free_undo_list ();
entry = current_history ();
if (entry)
entry->data = (char *)NULL;
}
_rl_kill_kbd_macro ();
rl_clear_message ();
_rl_init_argument ();
#if defined (SIGTSTP)
case SIGTSTP:
case SIGTTOU:
case SIGTTIN:
#endif /* SIGTSTP */
case SIGALRM:
case SIGTERM:
_rl_clean_up_for_exit ();
(*rl_deprep_term_function) ();
rl_clear_signals ();
rl_pending_input = 0;
#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 */
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_prep_term_function) (_rl_meta_flag);
rl_set_signals ();
}
SIGHANDLER_RETURN;
}
#if defined (SIGWINCH)
static RETSIGTYPE
rl_handle_sigwinch (sig)
int sig;
{
SigHandler *oh;
if (readline_echoing_p)
{
_rl_get_screen_size (fileno (rl_instream), 1);
_rl_redisplay_after_sigwinch ();
}
/* 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);
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;
{
#if defined (HAVE_POSIX_SIGNALS)
struct sigaction act;
act.sa_handler = handler;
act.sa_flags = 0;
sigemptyset (&act.sa_mask);
sigemptyset (&ohandler->sa_mask);
sigaction (sig, &act, ohandler);
#else
ohandler->sa_handler = (SigHandler *)signal (sig, handler);
#endif /* !HAVE_POSIX_SIGNALS */
return (ohandler->sa_handler);
}
int
rl_set_signals ()
{
sighandler_cxt dummy;
SigHandler *oh;
#if defined (HAVE_POSIX_SIGNALS)
sigemptyset (&dummy.sa_mask);
#endif
oh = rl_set_sighandler (SIGINT, rl_signal_handler, &old_int);
if (oh == (SigHandler *)SIG_IGN)
rl_sigaction (SIGINT, &old_int, &dummy);
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 (SHELL)
#if defined (SIGTSTP)
oh = rl_set_sighandler (SIGTSTP, rl_signal_handler, &old_tstp);
if (oh == (SigHandler *)SIG_IGN)
rl_sigaction (SIGTSTP, &old_tstp, &dummy);
#else
oh = (SigHandler *)NULL;
#endif /* SIGTSTP */
#if defined (SIGTTOU)
rl_set_sighandler (SIGTTOU, rl_signal_handler, &old_ttou);
rl_set_sighandler (SIGTTIN, rl_signal_handler, &old_ttin);
if (oh == (SigHandler *)SIG_IGN)
{
rl_set_sighandler (SIGTTOU, SIG_IGN, &dummy);
rl_set_sighandler (SIGTTIN, SIG_IGN, &dummy);
}
#endif /* SIGTTOU */
/* Handle SIGTERM if we're not being compiled as part of bash. */
rl_set_sighandler (SIGTERM, rl_signal_handler, &old_term);
#endif /* !SHELL */
#if defined (SIGWINCH)
rl_set_sighandler (SIGWINCH, rl_handle_sigwinch, &old_winch);
#endif /* SIGWINCH */
return 0;
}
int
rl_clear_signals ()
{
sighandler_cxt dummy;
#if defined (HAVE_POSIX_SIGNALS)
sigemptyset (&dummy.sa_mask);
#endif
rl_sigaction (SIGINT, &old_int, &dummy);
rl_sigaction (SIGALRM, &old_alrm, &dummy);
#if !defined (SHELL)
#if defined (SIGTSTP)
rl_sigaction (SIGTSTP, &old_tstp, &dummy);
#endif
#if defined (SIGTTOU)
rl_sigaction (SIGTTOU, &old_ttou, &dummy);
rl_sigaction (SIGTTIN, &old_ttin, &dummy);
#endif /* SIGTTOU */
rl_sigaction (SIGTERM, &old_term, &dummy);
#endif /* !SHELL */
#if defined (SIGWINCH)
sigemptyset (&dummy.sa_mask);
rl_sigaction (SIGWINCH, &old_winch, &dummy);
#endif
return 0;
}
#endif /* HANDLE_SIGNALS */