1 /* $NetBSD: tstp.c,v 1.45 2021/09/06 07:03:50 rin Exp $ */
2
3 /*
4 * Copyright (c) 1981, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)tstp.c 8.3 (Berkeley) 5/4/94";
36 #else
37 __RCSID("$NetBSD: tstp.c,v 1.45 2021/09/06 07:03:50 rin Exp $");
38 #endif
39 #endif /* not lint */
40
41 #include <sys/ioctl.h>
42 #include <sys/param.h>
43
44 #include <errno.h>
45 #include <signal.h>
46 #include <termios.h>
47 #include <unistd.h>
48
49 #include "curses.h"
50 #include "curses_private.h"
51
52 static int tstp_set;
53 static int winch_set;
54
55 static void (*otstpfn)(int) = SIG_DFL;
56
57 static struct sigaction owsa;
58 #ifndef TCSASOFT
59 #define TCSASOFT 0
60 #endif
61
62 /*
63 * stop_signal_handler --
64 * Handle stop signals.
65 */
66 void
__stop_signal_handler(int signo)67 __stop_signal_handler(/*ARGSUSED*/int signo)
68 {
69 sigset_t oset, set;
70
71 /*
72 * Block window change and timer signals. The latter is because
73 * applications use timers to decide when to repaint the screen.
74 */
75 (void)sigemptyset(&set);
76 (void)sigaddset(&set, SIGALRM);
77 (void)sigaddset(&set, SIGWINCH);
78 (void)sigprocmask(SIG_BLOCK, &set, &oset);
79
80 /*
81 * End the window, which also resets the terminal state to the
82 * original modes.
83 */
84 __stopwin();
85
86 /* Unblock SIGTSTP. */
87 (void)sigemptyset(&set);
88 (void)sigaddset(&set, SIGTSTP);
89 (void)sigprocmask(SIG_UNBLOCK, &set, NULL);
90
91 /* Stop ourselves. */
92 (void)kill(0, SIGTSTP);
93
94 /* Time passes ... */
95
96 /* restart things */
97 __restartwin();
98
99 /* Reset the signals. */
100 (void)sigprocmask(SIG_SETMASK, &oset, NULL);
101 }
102
103 /*
104 * Set the TSTP handler.
105 */
106 void
__set_stophandler(void)107 __set_stophandler(void)
108 {
109
110 __CTRACE(__CTRACE_MISC, "__set_stophandler: %d\n", tstp_set);
111 if (!tstp_set) {
112 otstpfn = signal(SIGTSTP, __stop_signal_handler);
113 tstp_set = 1;
114 }
115 }
116
117 /*
118 * Restore the TSTP handler.
119 */
120 void
__restore_stophandler(void)121 __restore_stophandler(void)
122 {
123
124 __CTRACE(__CTRACE_MISC, "__restore_stophandler: %d\n", tstp_set);
125 if (tstp_set) {
126 (void)signal(SIGTSTP, otstpfn);
127 tstp_set = 0;
128 }
129 }
130
131 /*
132 * winch_signal_handler --
133 * Handle winch signals by pushing KEY_RESIZE into the input stream.
134 */
135 void
__winch_signal_handler(int signo)136 __winch_signal_handler(/*ARGSUSED*/int signo)
137 {
138 struct winsize win;
139
140 if (ioctl(fileno(_cursesi_screen->outfd), TIOCGWINSZ, &win) != -1 &&
141 win.ws_row != 0 && win.ws_col != 0)
142 {
143 LINES = win.ws_row;
144 COLS = win.ws_col;
145 }
146 /*
147 * If there was a previous handler, call that,
148 * otherwise tell getch() to send KEY_RESIZE.
149 */
150 if (owsa.sa_handler != SIG_DFL &&
151 owsa.sa_handler != SIG_IGN &&
152 owsa.sa_handler != SIG_ERR &&
153 owsa.sa_handler != SIG_HOLD)
154 owsa.sa_handler(signo);
155 else
156 _cursesi_screen->resized = 1;
157 }
158
159 /*
160 * Set the WINCH handler.
161 */
162 void
__set_winchhandler(void)163 __set_winchhandler(void)
164 {
165
166 __CTRACE(__CTRACE_MISC, "__set_winchhandler: %d\n", winch_set);
167 if (!winch_set) {
168 struct sigaction sa;
169
170 sa.sa_handler = __winch_signal_handler;
171 sa.sa_flags = 0;
172 sigemptyset(&sa.sa_mask);
173 sigaction(SIGWINCH, &sa, &owsa);
174 winch_set = 1;
175 __CTRACE(__CTRACE_MISC,
176 "__set_winchhandler: owsa.sa_handler=%p\n",
177 owsa.sa_handler);
178 }
179 }
180
181 /*
182 * Restore the WINCH handler.
183 */
184 void
__restore_winchhandler(void)185 __restore_winchhandler(void)
186 {
187
188 __CTRACE(__CTRACE_MISC, "__restore_winchhandler: %d\n", winch_set);
189 if (winch_set > 0) {
190 struct sigaction cwsa;
191
192 sigaction(SIGWINCH, NULL, &cwsa);
193 if (cwsa.sa_handler == owsa.sa_handler) {
194 sigaction(SIGWINCH, &owsa, NULL);
195 winch_set = 0;
196 } else {
197 /*
198 * We're now using the programs WINCH handler,
199 * so don't restore the previous one.
200 */
201 winch_set = -1;
202 __CTRACE(__CTRACE_MISC, "cwsa.sa_handler = %p\n",
203 cwsa.sa_handler);
204 }
205 }
206 }
207
208 /* To allow both SIGTSTP and endwin() to come back nicely, we provide
209 the following routines. */
210
211 int
__stopwin(void)212 __stopwin(void)
213 {
214
215 __CTRACE(__CTRACE_MISC, "__stopwin\n");
216 if (_cursesi_screen == NULL)
217 return ERR;
218 if (_cursesi_screen->endwin)
219 return OK;
220
221 /* Get the current terminal state (which the user may have changed). */
222 (void)tcgetattr(fileno(_cursesi_screen->infd),
223 &_cursesi_screen->save_termios);
224
225 __restore_stophandler();
226 __restore_winchhandler();
227
228 if (curscr != NULL) {
229 __unsetattr(0);
230 __mvcur((int)curscr->cury, (int)curscr->curx,
231 (int)curscr->maxy - 1, 0, 0);
232 }
233
234 if (meta_on != NULL)
235 (void)tputs(meta_on, 0, __cputchar);
236
237 if ((curscr != NULL) && (curscr->flags & __KEYPAD))
238 (void)tputs(keypad_local, 0, __cputchar);
239 (void)tputs(cursor_normal, 0, __cputchar);
240 (void)tputs(exit_ca_mode, 0, __cputchar);
241 (void)fflush(_cursesi_screen->outfd);
242 #ifdef BSD
243 (void)setvbuf(_cursesi_screen->outfd, NULL, _IOLBF, 0);
244 #endif
245
246 _cursesi_screen->endwin = 1;
247
248 return tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSADRAIN,
249 &_cursesi_screen->orig_termios) ? ERR : OK;
250 }
251
252 void
__restartwin(void)253 __restartwin(void)
254 {
255 struct winsize win;
256 int nlines, ncols;
257
258 __CTRACE(__CTRACE_MISC, "__restartwin\n");
259 if (!_cursesi_screen->endwin)
260 return;
261
262 /* Reset the curses SIGTSTP and SIGWINCH signal handlers. */
263 __set_stophandler();
264 __set_winchhandler();
265
266 /*
267 * Check to see if the window size has changed.
268 * If the application didn't update LINES and COLS,
269 * set the * resized flag to tell getch() to push KEY_RESIZE.
270 * Update curscr (which also updates __virtscr) and stdscr
271 * to match the new size.
272 */
273 if (ioctl(fileno(_cursesi_screen->outfd), TIOCGWINSZ, &win) != -1 &&
274 win.ws_row != 0 && win.ws_col != 0)
275 {
276 if (win.ws_row != LINES) {
277 LINES = win.ws_row;
278 _cursesi_screen->resized = 1;
279 }
280 if (win.ws_col != COLS) {
281 COLS = win.ws_col;
282 _cursesi_screen->resized = 1;
283 }
284 }
285 /*
286 * We need to make local copies of LINES and COLS, otherwise we
287 * could lose if they are changed between wresize() calls.
288 */
289 nlines = LINES;
290 ncols = COLS;
291 if (curscr->maxy != nlines || curscr->maxx != ncols)
292 wresize(curscr, nlines, ncols);
293 if (stdscr->maxy != nlines || stdscr->maxx != ncols)
294 wresize(stdscr, nlines, ncols);
295
296 /* save the new "default" terminal state */
297 (void)tcgetattr(fileno(_cursesi_screen->infd),
298 &_cursesi_screen->orig_termios);
299
300 /* Reset the terminal state to the mode just before we stopped. */
301 (void)tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSADRAIN,
302 &_cursesi_screen->save_termios);
303
304 /* Restore colours */
305 __restore_colors();
306
307 /* Reset meta */
308 __restore_meta_state();
309
310 /* Restart the screen. */
311 __startwin(_cursesi_screen);
312
313 /* Reset cursor visibility */
314 __restore_cursor_vis();
315
316 /* Repaint the screen. */
317 wrefresh(curscr);
318 }
319
320 int
def_prog_mode(void)321 def_prog_mode(void)
322 {
323
324 if (_cursesi_screen->endwin)
325 return ERR;
326
327 return tcgetattr(fileno(_cursesi_screen->infd),
328 &_cursesi_screen->save_termios) ? ERR : OK;
329 }
330
331 int
reset_prog_mode(void)332 reset_prog_mode(void)
333 {
334
335 return tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSADRAIN,
336 &_cursesi_screen->save_termios) ? ERR : OK;
337 }
338
339 int
def_shell_mode(void)340 def_shell_mode(void)
341 {
342
343 return tcgetattr(fileno(_cursesi_screen->infd),
344 &_cursesi_screen->orig_termios) ? ERR : OK;
345 }
346
347 int
reset_shell_mode(void)348 reset_shell_mode(void)
349 {
350
351 return __stopwin();
352 }
353