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Diffstat (limited to 'readline/signals.c')
| -rw-r--r-- | readline/signals.c | 394 |
1 files changed, 394 insertions, 0 deletions
diff --git a/readline/signals.c b/readline/signals.c new file mode 100644 index 00000000000..3a34432f143 --- /dev/null +++ b/readline/signals.c @@ -0,0 +1,394 @@ +/* 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" + +#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 (); + +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 (); + +static SigHandler *rl_set_sighandler (); + +/* 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; +static int sigwinch_set_flag; + +/* **************************************************************** */ +/* */ +/* 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; int sa_mask, sa_flags; } sighandler_cxt; +# define sigemptyset(m) +#endif /* !HAVE_POSIX_SIGNALS */ + +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 */ + +#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 */ + + 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 (); + } + + 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_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); + + 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); +} + +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_pending_input = 0; +} + +/* 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; + + 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 */ |