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d60d9f65 SS |
1 | /* signals.c -- signal handling support for readline. */ |
2 | ||
3 | /* Copyright (C) 1987, 1989, 1992 Free Software Foundation, Inc. | |
4 | ||
5 | This file is part of the GNU Readline Library, a library for | |
6 | reading lines of text with interactive input and history editing. | |
7 | ||
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 | |
f9267e15 | 10 | as published by the Free Software Foundation; either version 2, or |
d60d9f65 SS |
11 | (at your option) any later version. |
12 | ||
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. | |
17 | ||
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, | |
f9267e15 | 21 | 59 Temple Place, Suite 330, Boston, MA 02111 USA. */ |
d60d9f65 SS |
22 | #define READLINE_LIBRARY |
23 | ||
24 | #if defined (HAVE_CONFIG_H) | |
25 | # include <config.h> | |
26 | #endif | |
27 | ||
28 | #include <stdio.h> /* Just for NULL. Yuck. */ | |
29 | #include <sys/types.h> | |
30 | #include <signal.h> | |
31 | ||
32 | #if defined (HAVE_UNISTD_H) | |
33 | # include <unistd.h> | |
34 | #endif /* HAVE_UNISTD_H */ | |
35 | ||
36 | /* System-specific feature definitions and include files. */ | |
37 | #include "rldefs.h" | |
38 | ||
39 | #if defined (GWINSZ_IN_SYS_IOCTL) | |
40 | # include <sys/ioctl.h> | |
41 | #endif /* GWINSZ_IN_SYS_IOCTL */ | |
42 | ||
d60d9f65 SS |
43 | #if defined (HANDLE_SIGNALS) |
44 | /* Some standard library routines. */ | |
45 | #include "readline.h" | |
46 | #include "history.h" | |
47 | ||
f9267e15 EZ |
48 | #include "rlprivate.h" |
49 | ||
d60d9f65 SS |
50 | #if !defined (RETSIGTYPE) |
51 | # if defined (VOID_SIGHANDLER) | |
52 | # define RETSIGTYPE void | |
53 | # else | |
54 | # define RETSIGTYPE int | |
55 | # endif /* !VOID_SIGHANDLER */ | |
56 | #endif /* !RETSIGTYPE */ | |
57 | ||
58 | #if defined (VOID_SIGHANDLER) | |
59 | # define SIGHANDLER_RETURN return | |
60 | #else | |
61 | # define SIGHANDLER_RETURN return (0) | |
62 | #endif | |
63 | ||
64 | /* This typedef is equivalant to the one for Function; it allows us | |
65 | to say SigHandler *foo = signal (SIGKILL, SIG_IGN); */ | |
66 | typedef RETSIGTYPE SigHandler (); | |
67 | ||
f9267e15 EZ |
68 | #if defined (HAVE_POSIX_SIGNALS) |
69 | typedef struct sigaction sighandler_cxt; | |
70 | # define rl_sigaction(s, nh, oh) sigaction(s, nh, oh) | |
71 | #else | |
72 | typedef struct { SigHandler *sa_handler; int sa_mask, sa_flags; } sighandler_cxt; | |
73 | # define sigemptyset(m) | |
74 | #endif /* !HAVE_POSIX_SIGNALS */ | |
c862e87b | 75 | |
f9267e15 | 76 | static SigHandler *rl_set_sighandler __P((int, SigHandler *, sighandler_cxt *)); |
d60d9f65 | 77 | |
c862e87b JM |
78 | /* Exported variables for use by applications. */ |
79 | ||
80 | /* If non-zero, readline will install its own signal handlers for | |
81 | SIGINT, SIGTERM, SIGQUIT, SIGALRM, SIGTSTP, SIGTTIN, and SIGTTOU. */ | |
82 | int rl_catch_signals = 1; | |
83 | ||
84 | /* If non-zero, readline will install a signal handler for SIGWINCH. */ | |
85 | #ifdef SIGWINCH | |
86 | int rl_catch_sigwinch = 1; | |
87 | #endif | |
88 | ||
89 | static int signals_set_flag; | |
90 | static int sigwinch_set_flag; | |
91 | ||
d60d9f65 SS |
92 | /* **************************************************************** */ |
93 | /* */ | |
94 | /* Signal Handling */ | |
95 | /* */ | |
96 | /* **************************************************************** */ | |
97 | ||
c862e87b JM |
98 | static sighandler_cxt old_int, old_term, old_alrm, old_quit; |
99 | #if defined (SIGTSTP) | |
d60d9f65 | 100 | static sighandler_cxt old_tstp, old_ttou, old_ttin; |
d60d9f65 | 101 | #endif |
d60d9f65 SS |
102 | #if defined (SIGWINCH) |
103 | static sighandler_cxt old_winch; | |
104 | #endif | |
105 | ||
106 | /* Readline signal handler functions. */ | |
107 | ||
108 | static RETSIGTYPE | |
109 | rl_signal_handler (sig) | |
110 | int sig; | |
111 | { | |
112 | #if defined (HAVE_POSIX_SIGNALS) | |
113 | sigset_t set; | |
114 | #else /* !HAVE_POSIX_SIGNALS */ | |
115 | # if defined (HAVE_BSD_SIGNALS) | |
116 | long omask; | |
117 | # else /* !HAVE_BSD_SIGNALS */ | |
118 | sighandler_cxt dummy_cxt; /* needed for rl_set_sighandler call */ | |
119 | # endif /* !HAVE_BSD_SIGNALS */ | |
120 | #endif /* !HAVE_POSIX_SIGNALS */ | |
121 | ||
122 | #if !defined (HAVE_BSD_SIGNALS) && !defined (HAVE_POSIX_SIGNALS) | |
123 | /* Since the signal will not be blocked while we are in the signal | |
124 | handler, ignore it until rl_clear_signals resets the catcher. */ | |
125 | if (sig == SIGINT || sig == SIGALRM) | |
126 | rl_set_sighandler (sig, SIG_IGN, &dummy_cxt); | |
127 | #endif /* !HAVE_BSD_SIGNALS && !HAVE_POSIX_SIGNALS */ | |
128 | ||
129 | switch (sig) | |
130 | { | |
131 | case SIGINT: | |
c862e87b JM |
132 | rl_free_line_state (); |
133 | /* FALLTHROUGH */ | |
d60d9f65 SS |
134 | |
135 | #if defined (SIGTSTP) | |
136 | case SIGTSTP: | |
137 | case SIGTTOU: | |
138 | case SIGTTIN: | |
139 | #endif /* SIGTSTP */ | |
140 | case SIGALRM: | |
141 | case SIGTERM: | |
c862e87b JM |
142 | case SIGQUIT: |
143 | rl_cleanup_after_signal (); | |
d60d9f65 SS |
144 | |
145 | #if defined (HAVE_POSIX_SIGNALS) | |
146 | sigprocmask (SIG_BLOCK, (sigset_t *)NULL, &set); | |
147 | sigdelset (&set, sig); | |
148 | #else /* !HAVE_POSIX_SIGNALS */ | |
149 | # if defined (HAVE_BSD_SIGNALS) | |
150 | omask = sigblock (0); | |
151 | # endif /* HAVE_BSD_SIGNALS */ | |
152 | #endif /* !HAVE_POSIX_SIGNALS */ | |
153 | ||
f9267e15 EZ |
154 | #if defined (__EMX__) |
155 | signal (sig, SIG_ACK); | |
156 | #endif | |
157 | ||
d60d9f65 SS |
158 | kill (getpid (), sig); |
159 | ||
160 | /* Let the signal that we just sent through. */ | |
161 | #if defined (HAVE_POSIX_SIGNALS) | |
162 | sigprocmask (SIG_SETMASK, &set, (sigset_t *)NULL); | |
163 | #else /* !HAVE_POSIX_SIGNALS */ | |
164 | # if defined (HAVE_BSD_SIGNALS) | |
165 | sigsetmask (omask & ~(sigmask (sig))); | |
166 | # endif /* HAVE_BSD_SIGNALS */ | |
167 | #endif /* !HAVE_POSIX_SIGNALS */ | |
168 | ||
c862e87b | 169 | rl_reset_after_signal (); |
d60d9f65 SS |
170 | } |
171 | ||
172 | SIGHANDLER_RETURN; | |
173 | } | |
174 | ||
175 | #if defined (SIGWINCH) | |
176 | static RETSIGTYPE | |
c862e87b | 177 | rl_sigwinch_handler (sig) |
d60d9f65 SS |
178 | int sig; |
179 | { | |
180 | SigHandler *oh; | |
181 | ||
182 | #if defined (MUST_REINSTALL_SIGHANDLERS) | |
183 | sighandler_cxt dummy_winch; | |
184 | ||
185 | /* We don't want to change old_winch -- it holds the state of SIGWINCH | |
186 | disposition set by the calling application. We need this state | |
187 | because we call the application's SIGWINCH handler after updating | |
188 | our own idea of the screen size. */ | |
c862e87b | 189 | rl_set_sighandler (SIGWINCH, rl_sigwinch_handler, &dummy_winch); |
d60d9f65 SS |
190 | #endif |
191 | ||
c862e87b | 192 | rl_resize_terminal (); |
d60d9f65 SS |
193 | |
194 | /* If another sigwinch handler has been installed, call it. */ | |
195 | oh = (SigHandler *)old_winch.sa_handler; | |
196 | if (oh && oh != (SigHandler *)SIG_IGN && oh != (SigHandler *)SIG_DFL) | |
197 | (*oh) (sig); | |
198 | ||
199 | SIGHANDLER_RETURN; | |
200 | } | |
201 | #endif /* SIGWINCH */ | |
202 | ||
203 | /* Functions to manage signal handling. */ | |
204 | ||
205 | #if !defined (HAVE_POSIX_SIGNALS) | |
206 | static int | |
207 | rl_sigaction (sig, nh, oh) | |
208 | int sig; | |
209 | sighandler_cxt *nh, *oh; | |
210 | { | |
211 | oh->sa_handler = signal (sig, nh->sa_handler); | |
212 | return 0; | |
213 | } | |
214 | #endif /* !HAVE_POSIX_SIGNALS */ | |
215 | ||
216 | /* Set up a readline-specific signal handler, saving the old signal | |
217 | information in OHANDLER. Return the old signal handler, like | |
218 | signal(). */ | |
219 | static SigHandler * | |
220 | rl_set_sighandler (sig, handler, ohandler) | |
221 | int sig; | |
222 | SigHandler *handler; | |
223 | sighandler_cxt *ohandler; | |
224 | { | |
f9267e15 | 225 | sighandler_cxt old_handler; |
d60d9f65 SS |
226 | #if defined (HAVE_POSIX_SIGNALS) |
227 | struct sigaction act; | |
228 | ||
229 | act.sa_handler = handler; | |
230 | act.sa_flags = 0; | |
231 | sigemptyset (&act.sa_mask); | |
232 | sigemptyset (&ohandler->sa_mask); | |
f9267e15 | 233 | sigaction (sig, &act, &old_handler); |
d60d9f65 | 234 | #else |
f9267e15 | 235 | old_handler.sa_handler = (SigHandler *)signal (sig, handler); |
d60d9f65 | 236 | #endif /* !HAVE_POSIX_SIGNALS */ |
f9267e15 EZ |
237 | |
238 | /* XXX -- assume we have memcpy */ | |
239 | /* If rl_set_signals is called twice in a row, don't set the old handler to | |
240 | rl_signal_handler, because that would cause infinite recursion. */ | |
241 | if (handler != rl_signal_handler || old_handler.sa_handler != rl_signal_handler) | |
242 | memcpy (ohandler, &old_handler, sizeof (sighandler_cxt)); | |
243 | ||
d60d9f65 SS |
244 | return (ohandler->sa_handler); |
245 | } | |
246 | ||
c862e87b JM |
247 | static void |
248 | rl_maybe_set_sighandler (sig, handler, ohandler) | |
249 | int sig; | |
250 | SigHandler *handler; | |
251 | sighandler_cxt *ohandler; | |
d60d9f65 SS |
252 | { |
253 | sighandler_cxt dummy; | |
254 | SigHandler *oh; | |
255 | ||
d60d9f65 | 256 | sigemptyset (&dummy.sa_mask); |
c862e87b | 257 | oh = rl_set_sighandler (sig, handler, ohandler); |
d60d9f65 | 258 | if (oh == (SigHandler *)SIG_IGN) |
c862e87b JM |
259 | rl_sigaction (sig, ohandler, &dummy); |
260 | } | |
d60d9f65 | 261 | |
c862e87b JM |
262 | int |
263 | rl_set_signals () | |
264 | { | |
265 | sighandler_cxt dummy; | |
266 | SigHandler *oh; | |
267 | ||
268 | if (rl_catch_signals && signals_set_flag == 0) | |
269 | { | |
270 | rl_maybe_set_sighandler (SIGINT, rl_signal_handler, &old_int); | |
271 | rl_maybe_set_sighandler (SIGTERM, rl_signal_handler, &old_term); | |
272 | rl_maybe_set_sighandler (SIGQUIT, rl_signal_handler, &old_quit); | |
273 | ||
274 | oh = rl_set_sighandler (SIGALRM, rl_signal_handler, &old_alrm); | |
275 | if (oh == (SigHandler *)SIG_IGN) | |
276 | rl_sigaction (SIGALRM, &old_alrm, &dummy); | |
d60d9f65 | 277 | #if defined (HAVE_POSIX_SIGNALS) && defined (SA_RESTART) |
c862e87b JM |
278 | /* If the application using readline has already installed a signal |
279 | handler with SA_RESTART, SIGALRM will cause reads to be restarted | |
280 | automatically, so readline should just get out of the way. Since | |
281 | we tested for SIG_IGN above, we can just test for SIG_DFL here. */ | |
282 | if (oh != (SigHandler *)SIG_DFL && (old_alrm.sa_flags & SA_RESTART)) | |
283 | rl_sigaction (SIGALRM, &old_alrm, &dummy); | |
d60d9f65 SS |
284 | #endif /* HAVE_POSIX_SIGNALS */ |
285 | ||
d60d9f65 | 286 | #if defined (SIGTSTP) |
c862e87b | 287 | rl_maybe_set_sighandler (SIGTSTP, rl_signal_handler, &old_tstp); |
d60d9f65 SS |
288 | #endif /* SIGTSTP */ |
289 | ||
290 | #if defined (SIGTTOU) | |
c862e87b | 291 | rl_maybe_set_sighandler (SIGTTOU, rl_signal_handler, &old_ttou); |
d60d9f65 SS |
292 | #endif /* SIGTTOU */ |
293 | ||
c862e87b JM |
294 | #if defined (SIGTTIN) |
295 | rl_maybe_set_sighandler (SIGTTIN, rl_signal_handler, &old_ttin); | |
296 | #endif /* SIGTTIN */ | |
d60d9f65 | 297 | |
c862e87b JM |
298 | signals_set_flag = 1; |
299 | } | |
d60d9f65 SS |
300 | |
301 | #if defined (SIGWINCH) | |
c862e87b JM |
302 | if (rl_catch_sigwinch && sigwinch_set_flag == 0) |
303 | { | |
304 | rl_maybe_set_sighandler (SIGWINCH, rl_sigwinch_handler, &old_winch); | |
305 | sigwinch_set_flag = 1; | |
306 | } | |
d60d9f65 SS |
307 | #endif /* SIGWINCH */ |
308 | ||
309 | return 0; | |
310 | } | |
311 | ||
312 | int | |
313 | rl_clear_signals () | |
314 | { | |
315 | sighandler_cxt dummy; | |
316 | ||
c862e87b JM |
317 | if (rl_catch_signals && signals_set_flag == 1) |
318 | { | |
319 | sigemptyset (&dummy.sa_mask); | |
d60d9f65 | 320 | |
c862e87b JM |
321 | rl_sigaction (SIGINT, &old_int, &dummy); |
322 | rl_sigaction (SIGTERM, &old_term, &dummy); | |
323 | rl_sigaction (SIGQUIT, &old_quit, &dummy); | |
324 | rl_sigaction (SIGALRM, &old_alrm, &dummy); | |
d60d9f65 SS |
325 | |
326 | #if defined (SIGTSTP) | |
c862e87b JM |
327 | rl_sigaction (SIGTSTP, &old_tstp, &dummy); |
328 | #endif /* SIGTSTP */ | |
d60d9f65 SS |
329 | |
330 | #if defined (SIGTTOU) | |
c862e87b | 331 | rl_sigaction (SIGTTOU, &old_ttou, &dummy); |
d60d9f65 SS |
332 | #endif /* SIGTTOU */ |
333 | ||
c862e87b JM |
334 | #if defined (SIGTTIN) |
335 | rl_sigaction (SIGTTIN, &old_ttin, &dummy); | |
336 | #endif /* SIGTTIN */ | |
d60d9f65 | 337 | |
c862e87b JM |
338 | signals_set_flag = 0; |
339 | } | |
d60d9f65 SS |
340 | |
341 | #if defined (SIGWINCH) | |
c862e87b JM |
342 | if (rl_catch_sigwinch && sigwinch_set_flag == 1) |
343 | { | |
344 | sigemptyset (&dummy.sa_mask); | |
345 | rl_sigaction (SIGWINCH, &old_winch, &dummy); | |
346 | sigwinch_set_flag = 0; | |
347 | } | |
d60d9f65 SS |
348 | #endif |
349 | ||
350 | return 0; | |
351 | } | |
c862e87b JM |
352 | |
353 | /* Clean up the terminal and readline state after catching a signal, before | |
354 | resending it to the calling application. */ | |
355 | void | |
356 | rl_cleanup_after_signal () | |
357 | { | |
358 | _rl_clean_up_for_exit (); | |
359 | (*rl_deprep_term_function) (); | |
360 | rl_clear_signals (); | |
361 | rl_pending_input = 0; | |
362 | } | |
363 | ||
364 | /* Reset the terminal and readline state after a signal handler returns. */ | |
365 | void | |
366 | rl_reset_after_signal () | |
367 | { | |
368 | (*rl_prep_term_function) (_rl_meta_flag); | |
369 | rl_set_signals (); | |
370 | } | |
371 | ||
372 | /* Free up the readline variable line state for the current line (undo list, | |
373 | any partial history entry, any keyboard macros in progress, and any | |
374 | numeric arguments in process) after catching a signal, before calling | |
375 | rl_cleanup_after_signal(). */ | |
376 | void | |
377 | rl_free_line_state () | |
378 | { | |
379 | register HIST_ENTRY *entry; | |
380 | ||
381 | free_undo_list (); | |
382 | ||
383 | entry = current_history (); | |
384 | if (entry) | |
385 | entry->data = (char *)NULL; | |
386 | ||
387 | _rl_kill_kbd_macro (); | |
388 | rl_clear_message (); | |
389 | _rl_init_argument (); | |
390 | } | |
391 | ||
d60d9f65 | 392 | #endif /* HANDLE_SIGNALS */ |