1 /* signals.c -- signal handling support for readline. */
3 /* Copyright (C) 1987, 1989, 1992 Free Software Foundation, Inc.
5 This file is part of the GNU Readline Library, a library for
6 reading lines of text with interactive input and history editing.
8 The GNU Readline Library is free software; you can redistribute it
9 and/or modify it under the terms of the GNU General Public License
10 as published by the Free Software Foundation; either version 2, or
11 (at your option) any later version.
13 The GNU Readline Library is distributed in the hope that it will be
14 useful, but WITHOUT ANY WARRANTY; without even the implied warranty
15 of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 The GNU General Public License is often shipped with GNU software, and
19 is generally kept in a file called COPYING or LICENSE. If you do not
20 have a copy of the license, write to the Free Software Foundation,
21 59 Temple Place, Suite 330, Boston, MA 02111 USA. */
22 #define READLINE_LIBRARY
24 #if defined (HAVE_CONFIG_H)
28 #include <stdio.h> /* Just for NULL. Yuck. */
29 #include <sys/types.h>
32 #if defined (HAVE_UNISTD_H)
34 #endif /* HAVE_UNISTD_H */
36 /* System-specific feature definitions and include files. */
39 #if defined (GWINSZ_IN_SYS_IOCTL)
40 # include <sys/ioctl.h>
41 #endif /* GWINSZ_IN_SYS_IOCTL */
43 #if defined (HANDLE_SIGNALS)
44 /* Some standard library routines. */
48 #include "rlprivate.h"
50 #if !defined (RETSIGTYPE)
51 # if defined (VOID_SIGHANDLER)
52 # define RETSIGTYPE void
54 # define RETSIGTYPE int
55 # endif /* !VOID_SIGHANDLER */
56 #endif /* !RETSIGTYPE */
58 #if defined (VOID_SIGHANDLER)
59 # define SIGHANDLER_RETURN return
61 # define SIGHANDLER_RETURN return (0)
64 /* This typedef is equivalent to the one for Function; it allows us
65 to say SigHandler *foo = signal (SIGKILL, SIG_IGN); */
66 typedef RETSIGTYPE SigHandler ();
68 #if defined (HAVE_POSIX_SIGNALS)
69 typedef struct sigaction sighandler_cxt;
70 # define rl_sigaction(s, nh, oh) sigaction(s, nh, oh)
72 typedef struct { SigHandler *sa_handler; int sa_mask, sa_flags; } sighandler_cxt;
73 # define sigemptyset(m)
74 #endif /* !HAVE_POSIX_SIGNALS */
76 static SigHandler *rl_set_sighandler PARAMS((int, SigHandler *, sighandler_cxt *));
77 static void rl_maybe_set_sighandler PARAMS((int, SigHandler *, sighandler_cxt *));
79 /* Exported variables for use by applications. */
81 /* If non-zero, readline will install its own signal handlers for
82 SIGINT, SIGTERM, SIGQUIT, SIGALRM, SIGTSTP, SIGTTIN, and SIGTTOU. */
83 int rl_catch_signals = 1;
85 /* If non-zero, readline will install a signal handler for SIGWINCH. */
87 int rl_catch_sigwinch = 1;
90 static int signals_set_flag;
91 static int sigwinch_set_flag;
93 /* **************************************************************** */
97 /* **************************************************************** */
99 static sighandler_cxt old_int, old_term, old_alrm, old_quit;
100 #if defined (SIGTSTP)
101 static sighandler_cxt old_tstp, old_ttou, old_ttin;
103 #if defined (SIGWINCH)
104 static sighandler_cxt old_winch;
107 /* Readline signal handler functions. */
110 rl_signal_handler (sig)
113 #if defined (HAVE_POSIX_SIGNALS)
115 #else /* !HAVE_POSIX_SIGNALS */
116 # if defined (HAVE_BSD_SIGNALS)
118 # else /* !HAVE_BSD_SIGNALS */
119 sighandler_cxt dummy_cxt; /* needed for rl_set_sighandler call */
120 # endif /* !HAVE_BSD_SIGNALS */
121 #endif /* !HAVE_POSIX_SIGNALS */
123 RL_SETSTATE(RL_STATE_SIGHANDLER);
125 #if !defined (HAVE_BSD_SIGNALS) && !defined (HAVE_POSIX_SIGNALS)
126 /* Since the signal will not be blocked while we are in the signal
127 handler, ignore it until rl_clear_signals resets the catcher. */
128 if (sig == SIGINT || sig == SIGALRM)
129 rl_set_sighandler (sig, SIG_IGN, &dummy_cxt);
130 #endif /* !HAVE_BSD_SIGNALS && !HAVE_POSIX_SIGNALS */
135 rl_free_line_state ();
138 #if defined (SIGTSTP)
146 rl_cleanup_after_signal ();
148 #if defined (HAVE_POSIX_SIGNALS)
149 sigprocmask (SIG_BLOCK, (sigset_t *)NULL, &set);
150 sigdelset (&set, sig);
151 #else /* !HAVE_POSIX_SIGNALS */
152 # if defined (HAVE_BSD_SIGNALS)
153 omask = sigblock (0);
154 # endif /* HAVE_BSD_SIGNALS */
155 #endif /* !HAVE_POSIX_SIGNALS */
157 #if defined (__EMX__)
158 signal (sig, SIG_ACK);
161 kill (getpid (), sig);
163 /* Let the signal that we just sent through. */
164 #if defined (HAVE_POSIX_SIGNALS)
165 sigprocmask (SIG_SETMASK, &set, (sigset_t *)NULL);
166 #else /* !HAVE_POSIX_SIGNALS */
167 # if defined (HAVE_BSD_SIGNALS)
168 sigsetmask (omask & ~(sigmask (sig)));
169 # endif /* HAVE_BSD_SIGNALS */
170 #endif /* !HAVE_POSIX_SIGNALS */
172 rl_reset_after_signal ();
175 RL_UNSETSTATE(RL_STATE_SIGHANDLER);
179 #if defined (SIGWINCH)
181 rl_sigwinch_handler (sig)
186 #if defined (MUST_REINSTALL_SIGHANDLERS)
187 sighandler_cxt dummy_winch;
189 /* We don't want to change old_winch -- it holds the state of SIGWINCH
190 disposition set by the calling application. We need this state
191 because we call the application's SIGWINCH handler after updating
192 our own idea of the screen size. */
193 rl_set_sighandler (SIGWINCH, rl_sigwinch_handler, &dummy_winch);
196 RL_SETSTATE(RL_STATE_SIGHANDLER);
197 rl_resize_terminal ();
199 /* If another sigwinch handler has been installed, call it. */
200 oh = (SigHandler *)old_winch.sa_handler;
201 if (oh && oh != (SigHandler *)SIG_IGN && oh != (SigHandler *)SIG_DFL)
204 RL_UNSETSTATE(RL_STATE_SIGHANDLER);
207 #endif /* SIGWINCH */
209 /* Functions to manage signal handling. */
211 #if !defined (HAVE_POSIX_SIGNALS)
213 rl_sigaction (sig, nh, oh)
215 sighandler_cxt *nh, *oh;
217 oh->sa_handler = signal (sig, nh->sa_handler);
220 #endif /* !HAVE_POSIX_SIGNALS */
222 /* Set up a readline-specific signal handler, saving the old signal
223 information in OHANDLER. Return the old signal handler, like
226 rl_set_sighandler (sig, handler, ohandler)
229 sighandler_cxt *ohandler;
231 sighandler_cxt old_handler;
232 #if defined (HAVE_POSIX_SIGNALS)
233 struct sigaction act;
235 act.sa_handler = handler;
236 act.sa_flags = 0; /* XXX - should we set SA_RESTART for SIGWINCH? */
237 sigemptyset (&act.sa_mask);
238 sigemptyset (&ohandler->sa_mask);
239 sigaction (sig, &act, &old_handler);
241 old_handler.sa_handler = (SigHandler *)signal (sig, handler);
242 #endif /* !HAVE_POSIX_SIGNALS */
244 /* XXX -- assume we have memcpy */
245 /* If rl_set_signals is called twice in a row, don't set the old handler to
246 rl_signal_handler, because that would cause infinite recursion. */
247 if (handler != rl_signal_handler || old_handler.sa_handler != rl_signal_handler)
248 memcpy (ohandler, &old_handler, sizeof (sighandler_cxt));
250 return (ohandler->sa_handler);
254 rl_maybe_set_sighandler (sig, handler, ohandler)
257 sighandler_cxt *ohandler;
259 sighandler_cxt dummy;
262 sigemptyset (&dummy.sa_mask);
263 oh = rl_set_sighandler (sig, handler, ohandler);
264 if (oh == (SigHandler *)SIG_IGN)
265 rl_sigaction (sig, ohandler, &dummy);
271 sighandler_cxt dummy;
274 if (rl_catch_signals && signals_set_flag == 0)
276 rl_maybe_set_sighandler (SIGINT, rl_signal_handler, &old_int);
277 rl_maybe_set_sighandler (SIGTERM, rl_signal_handler, &old_term);
278 rl_maybe_set_sighandler (SIGQUIT, rl_signal_handler, &old_quit);
280 oh = rl_set_sighandler (SIGALRM, rl_signal_handler, &old_alrm);
281 if (oh == (SigHandler *)SIG_IGN)
282 rl_sigaction (SIGALRM, &old_alrm, &dummy);
283 #if defined (HAVE_POSIX_SIGNALS) && defined (SA_RESTART)
284 /* If the application using readline has already installed a signal
285 handler with SA_RESTART, SIGALRM will cause reads to be restarted
286 automatically, so readline should just get out of the way. Since
287 we tested for SIG_IGN above, we can just test for SIG_DFL here. */
288 if (oh != (SigHandler *)SIG_DFL && (old_alrm.sa_flags & SA_RESTART))
289 rl_sigaction (SIGALRM, &old_alrm, &dummy);
290 #endif /* HAVE_POSIX_SIGNALS */
292 #if defined (SIGTSTP)
293 rl_maybe_set_sighandler (SIGTSTP, rl_signal_handler, &old_tstp);
296 #if defined (SIGTTOU)
297 rl_maybe_set_sighandler (SIGTTOU, rl_signal_handler, &old_ttou);
300 #if defined (SIGTTIN)
301 rl_maybe_set_sighandler (SIGTTIN, rl_signal_handler, &old_ttin);
304 signals_set_flag = 1;
307 #if defined (SIGWINCH)
308 if (rl_catch_sigwinch && sigwinch_set_flag == 0)
310 rl_maybe_set_sighandler (SIGWINCH, rl_sigwinch_handler, &old_winch);
311 sigwinch_set_flag = 1;
313 #endif /* SIGWINCH */
321 sighandler_cxt dummy;
323 if (rl_catch_signals && signals_set_flag == 1)
325 sigemptyset (&dummy.sa_mask);
327 rl_sigaction (SIGINT, &old_int, &dummy);
328 rl_sigaction (SIGTERM, &old_term, &dummy);
329 rl_sigaction (SIGQUIT, &old_quit, &dummy);
330 rl_sigaction (SIGALRM, &old_alrm, &dummy);
332 #if defined (SIGTSTP)
333 rl_sigaction (SIGTSTP, &old_tstp, &dummy);
336 #if defined (SIGTTOU)
337 rl_sigaction (SIGTTOU, &old_ttou, &dummy);
340 #if defined (SIGTTIN)
341 rl_sigaction (SIGTTIN, &old_ttin, &dummy);
344 signals_set_flag = 0;
347 #if defined (SIGWINCH)
348 if (rl_catch_sigwinch && sigwinch_set_flag == 1)
350 sigemptyset (&dummy.sa_mask);
351 rl_sigaction (SIGWINCH, &old_winch, &dummy);
352 sigwinch_set_flag = 0;
359 /* Clean up the terminal and readline state after catching a signal, before
360 resending it to the calling application. */
362 rl_cleanup_after_signal ()
364 _rl_clean_up_for_exit ();
365 (*rl_deprep_term_function) ();
367 rl_clear_pending_input ();
370 /* Reset the terminal and readline state after a signal handler returns. */
372 rl_reset_after_signal ()
374 (*rl_prep_term_function) (_rl_meta_flag);
378 /* Free up the readline variable line state for the current line (undo list,
379 any partial history entry, any keyboard macros in progress, and any
380 numeric arguments in process) after catching a signal, before calling
381 rl_cleanup_after_signal(). */
383 rl_free_line_state ()
385 register HIST_ENTRY *entry;
387 rl_free_undo_list ();
389 entry = current_history ();
391 entry->data = (char *)NULL;
393 _rl_kill_kbd_macro ();
395 _rl_init_argument ();
398 #endif /* HANDLE_SIGNALS */