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 1, 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,
21 675 Mass Ave, Cambridge, MA 02139, 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 (__GO32__) && !defined(__DJGPP__)
44 # undef HANDLE_SIGNALS
45 #endif /* __GO32__ && !__DJGPP__ */
47 #if defined (HANDLE_SIGNALS)
48 /* Some standard library routines. */
52 #if !defined (RETSIGTYPE)
53 # if defined (VOID_SIGHANDLER)
54 # define RETSIGTYPE void
56 # define RETSIGTYPE int
57 # endif /* !VOID_SIGHANDLER */
58 #endif /* !RETSIGTYPE */
60 #if defined (VOID_SIGHANDLER)
61 # define SIGHANDLER_RETURN return
63 # define SIGHANDLER_RETURN return (0)
66 /* This typedef is equivalant to the one for Function; it allows us
67 to say SigHandler *foo = signal (SIGKILL, SIG_IGN); */
68 typedef RETSIGTYPE
SigHandler ();
70 extern int readline_echoing_p
;
71 extern int rl_pending_input
;
72 extern int _rl_meta_flag
;
74 extern void free_undo_list ();
75 extern void _rl_get_screen_size ();
76 extern void _rl_redisplay_after_sigwinch ();
77 extern void _rl_clean_up_for_exit ();
78 extern void _rl_kill_kbd_macro ();
79 extern void _rl_init_argument ();
80 extern void rl_deprep_terminal (), rl_prep_terminal ();
82 static SigHandler
*rl_set_sighandler ();
84 /* Exported variables for use by applications. */
86 /* If non-zero, readline will install its own signal handlers for
87 SIGINT, SIGTERM, SIGQUIT, SIGALRM, SIGTSTP, SIGTTIN, and SIGTTOU. */
88 int rl_catch_signals
= 1;
90 /* If non-zero, readline will install a signal handler for SIGWINCH. */
92 int rl_catch_sigwinch
= 1;
95 static int signals_set_flag
;
97 static int sigwinch_set_flag
;
100 /* **************************************************************** */
102 /* Signal Handling */
104 /* **************************************************************** */
106 #if defined (HAVE_POSIX_SIGNALS)
107 typedef struct sigaction sighandler_cxt
;
108 # define rl_sigaction(s, nh, oh) sigaction(s, nh, oh)
110 typedef struct { SigHandler
*sa_handler
; int sa_mask
, sa_flags
; } sighandler_cxt
;
111 # define sigemptyset(m)
112 #endif /* !HAVE_POSIX_SIGNALS */
114 static sighandler_cxt old_int
, old_term
, old_alrm
, old_quit
;
115 #if defined (SIGTSTP)
116 static sighandler_cxt old_tstp
, old_ttou
, old_ttin
;
118 #if defined (SIGWINCH)
119 static sighandler_cxt old_winch
;
122 /* Readline signal handler functions. */
125 rl_signal_handler (sig
)
128 #if defined (HAVE_POSIX_SIGNALS)
130 #else /* !HAVE_POSIX_SIGNALS */
131 # if defined (HAVE_BSD_SIGNALS)
133 # else /* !HAVE_BSD_SIGNALS */
134 sighandler_cxt dummy_cxt
; /* needed for rl_set_sighandler call */
135 # endif /* !HAVE_BSD_SIGNALS */
136 #endif /* !HAVE_POSIX_SIGNALS */
138 #if !defined (HAVE_BSD_SIGNALS) && !defined (HAVE_POSIX_SIGNALS)
139 /* Since the signal will not be blocked while we are in the signal
140 handler, ignore it until rl_clear_signals resets the catcher. */
141 if (sig
== SIGINT
|| sig
== SIGALRM
)
142 rl_set_sighandler (sig
, SIG_IGN
, &dummy_cxt
);
143 #endif /* !HAVE_BSD_SIGNALS && !HAVE_POSIX_SIGNALS */
148 rl_free_line_state ();
151 #if defined (SIGTSTP)
159 rl_cleanup_after_signal ();
161 #if defined (HAVE_POSIX_SIGNALS)
162 sigprocmask (SIG_BLOCK
, (sigset_t
*)NULL
, &set
);
163 sigdelset (&set
, sig
);
164 #else /* !HAVE_POSIX_SIGNALS */
165 # if defined (HAVE_BSD_SIGNALS)
166 omask
= sigblock (0);
167 # endif /* HAVE_BSD_SIGNALS */
168 #endif /* !HAVE_POSIX_SIGNALS */
170 kill (getpid (), sig
);
172 /* Let the signal that we just sent through. */
173 #if defined (HAVE_POSIX_SIGNALS)
174 sigprocmask (SIG_SETMASK
, &set
, (sigset_t
*)NULL
);
175 #else /* !HAVE_POSIX_SIGNALS */
176 # if defined (HAVE_BSD_SIGNALS)
177 sigsetmask (omask
& ~(sigmask (sig
)));
178 # endif /* HAVE_BSD_SIGNALS */
179 #endif /* !HAVE_POSIX_SIGNALS */
181 rl_reset_after_signal ();
187 #if defined (SIGWINCH)
189 rl_sigwinch_handler (sig
)
194 #if defined (MUST_REINSTALL_SIGHANDLERS)
195 sighandler_cxt dummy_winch
;
197 /* We don't want to change old_winch -- it holds the state of SIGWINCH
198 disposition set by the calling application. We need this state
199 because we call the application's SIGWINCH handler after updating
200 our own idea of the screen size. */
201 rl_set_sighandler (SIGWINCH
, rl_sigwinch_handler
, &dummy_winch
);
204 rl_resize_terminal ();
206 /* If another sigwinch handler has been installed, call it. */
207 oh
= (SigHandler
*)old_winch
.sa_handler
;
208 if (oh
&& oh
!= (SigHandler
*)SIG_IGN
&& oh
!= (SigHandler
*)SIG_DFL
)
213 #endif /* SIGWINCH */
215 /* Functions to manage signal handling. */
217 #if !defined (HAVE_POSIX_SIGNALS)
219 rl_sigaction (sig
, nh
, oh
)
221 sighandler_cxt
*nh
, *oh
;
223 oh
->sa_handler
= signal (sig
, nh
->sa_handler
);
226 #endif /* !HAVE_POSIX_SIGNALS */
228 /* Set up a readline-specific signal handler, saving the old signal
229 information in OHANDLER. Return the old signal handler, like
232 rl_set_sighandler (sig
, handler
, ohandler
)
235 sighandler_cxt
*ohandler
;
237 #if defined (HAVE_POSIX_SIGNALS)
238 struct sigaction act
;
240 act
.sa_handler
= handler
;
242 sigemptyset (&act
.sa_mask
);
243 sigemptyset (&ohandler
->sa_mask
);
244 sigaction (sig
, &act
, ohandler
);
246 ohandler
->sa_handler
= (SigHandler
*)signal (sig
, handler
);
247 #endif /* !HAVE_POSIX_SIGNALS */
248 return (ohandler
->sa_handler
);
252 rl_maybe_set_sighandler (sig
, handler
, ohandler
)
255 sighandler_cxt
*ohandler
;
257 sighandler_cxt dummy
;
260 sigemptyset (&dummy
.sa_mask
);
261 oh
= rl_set_sighandler (sig
, handler
, ohandler
);
262 if (oh
== (SigHandler
*)SIG_IGN
)
263 rl_sigaction (sig
, ohandler
, &dummy
);
269 sighandler_cxt dummy
;
272 if (rl_catch_signals
&& signals_set_flag
== 0)
274 rl_maybe_set_sighandler (SIGINT
, rl_signal_handler
, &old_int
);
275 rl_maybe_set_sighandler (SIGTERM
, rl_signal_handler
, &old_term
);
276 rl_maybe_set_sighandler (SIGQUIT
, rl_signal_handler
, &old_quit
);
278 oh
= rl_set_sighandler (SIGALRM
, rl_signal_handler
, &old_alrm
);
279 if (oh
== (SigHandler
*)SIG_IGN
)
280 rl_sigaction (SIGALRM
, &old_alrm
, &dummy
);
281 #if defined (HAVE_POSIX_SIGNALS) && defined (SA_RESTART)
282 /* If the application using readline has already installed a signal
283 handler with SA_RESTART, SIGALRM will cause reads to be restarted
284 automatically, so readline should just get out of the way. Since
285 we tested for SIG_IGN above, we can just test for SIG_DFL here. */
286 if (oh
!= (SigHandler
*)SIG_DFL
&& (old_alrm
.sa_flags
& SA_RESTART
))
287 rl_sigaction (SIGALRM
, &old_alrm
, &dummy
);
288 #endif /* HAVE_POSIX_SIGNALS */
290 #if defined (SIGTSTP)
291 rl_maybe_set_sighandler (SIGTSTP
, rl_signal_handler
, &old_tstp
);
294 #if defined (SIGTTOU)
295 rl_maybe_set_sighandler (SIGTTOU
, rl_signal_handler
, &old_ttou
);
298 #if defined (SIGTTIN)
299 rl_maybe_set_sighandler (SIGTTIN
, rl_signal_handler
, &old_ttin
);
302 signals_set_flag
= 1;
305 #if defined (SIGWINCH)
306 if (rl_catch_sigwinch
&& sigwinch_set_flag
== 0)
308 rl_maybe_set_sighandler (SIGWINCH
, rl_sigwinch_handler
, &old_winch
);
309 sigwinch_set_flag
= 1;
311 #endif /* SIGWINCH */
319 sighandler_cxt dummy
;
321 if (rl_catch_signals
&& signals_set_flag
== 1)
323 sigemptyset (&dummy
.sa_mask
);
325 rl_sigaction (SIGINT
, &old_int
, &dummy
);
326 rl_sigaction (SIGTERM
, &old_term
, &dummy
);
327 rl_sigaction (SIGQUIT
, &old_quit
, &dummy
);
328 rl_sigaction (SIGALRM
, &old_alrm
, &dummy
);
330 #if defined (SIGTSTP)
331 rl_sigaction (SIGTSTP
, &old_tstp
, &dummy
);
334 #if defined (SIGTTOU)
335 rl_sigaction (SIGTTOU
, &old_ttou
, &dummy
);
338 #if defined (SIGTTIN)
339 rl_sigaction (SIGTTIN
, &old_ttin
, &dummy
);
342 signals_set_flag
= 0;
345 #if defined (SIGWINCH)
346 if (rl_catch_sigwinch
&& sigwinch_set_flag
== 1)
348 sigemptyset (&dummy
.sa_mask
);
349 rl_sigaction (SIGWINCH
, &old_winch
, &dummy
);
350 sigwinch_set_flag
= 0;
357 /* Clean up the terminal and readline state after catching a signal, before
358 resending it to the calling application. */
360 rl_cleanup_after_signal ()
362 _rl_clean_up_for_exit ();
363 (*rl_deprep_term_function
) ();
365 rl_pending_input
= 0;
368 /* Reset the terminal and readline state after a signal handler returns. */
370 rl_reset_after_signal ()
372 (*rl_prep_term_function
) (_rl_meta_flag
);
376 /* Free up the readline variable line state for the current line (undo list,
377 any partial history entry, any keyboard macros in progress, and any
378 numeric arguments in process) after catching a signal, before calling
379 rl_cleanup_after_signal(). */
381 rl_free_line_state ()
383 register HIST_ENTRY
*entry
;
387 entry
= current_history ();
389 entry
->data
= (char *)NULL
;
391 _rl_kill_kbd_macro ();
393 _rl_init_argument ();
396 #endif /* HANDLE_SIGNALS */