xref: /netbsd-src/lib/libcurses/tstp.c (revision d20841bb642898112fe68f0ad3f7b26dddf56f07)
1 /*	$NetBSD: tstp.c,v 1.30 2003/08/07 16:44:25 agc 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 1.30 2003/08/07 16:44:25 agc Exp $");
38 #endif
39 #endif				/* not lint */
40 
41 #include <errno.h>
42 #include <signal.h>
43 #include <termios.h>
44 #include <unistd.h>
45 
46 #include "curses.h"
47 #include "curses_private.h"
48 
49 /*
50  * stop_signal_handler --
51  *	Handle stop signals.
52  */
53 void
54 __stop_signal_handler(/*ARGSUSED*/int signo)
55 {
56 	sigset_t oset, set;
57 
58 	/*
59 	 * Block window change and timer signals.  The latter is because
60 	 * applications use timers to decide when to repaint the screen.
61 	 */
62 	(void) sigemptyset(&set);
63 	(void) sigaddset(&set, SIGALRM);
64 	(void) sigaddset(&set, SIGWINCH);
65 	(void) sigprocmask(SIG_BLOCK, &set, &oset);
66 
67 	/*
68 	 * End the window, which also resets the terminal state to the
69 	 * original modes.
70 	 */
71 	__stopwin();
72 
73 	/* Unblock SIGTSTP. */
74 	(void) sigemptyset(&set);
75 	(void) sigaddset(&set, SIGTSTP);
76 	(void) sigprocmask(SIG_UNBLOCK, &set, NULL);
77 
78 	/* Stop ourselves. */
79 	(void) kill(0, SIGTSTP);
80 
81 	/* Time passes ... */
82 
83 	/* restart things */
84 	__restartwin();
85 
86 	/* Reset the signals. */
87 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
88 }
89 
90 static void (*otstpfn)
91 __P((int)) = SIG_DFL;
92 
93 /*
94  * Set the TSTP handler.
95  */
96 void
97 __set_stophandler(void)
98 {
99 	otstpfn = signal(SIGTSTP, __stop_signal_handler);
100 }
101 
102 /*
103  * Restore the TSTP handler.
104  */
105 void
106 __restore_stophandler(void)
107 {
108 	(void) signal(SIGTSTP, otstpfn);
109 }
110 
111 
112 /* To allow both SIGTSTP and endwin() to come back nicely, we provide
113    the following routines. */
114 
115 int
116 __stopwin(void)
117 {
118 	if (_cursesi_screen->endwin)
119 		return OK;
120 
121 	/* Get the current terminal state (which the user may have changed). */
122 	(void) tcgetattr(fileno(_cursesi_screen->infd),
123 			 &_cursesi_screen->save_termios);
124 
125 	__restore_stophandler();
126 
127 	if (curscr != NULL) {
128 		__unsetattr(0);
129 		__mvcur((int) curscr->cury, (int) curscr->curx, (int) curscr->maxy - 1, 0, 0);
130 	}
131 
132 	if (__tc_mo != NULL)
133 		(void) tputs(__tc_mo, 0, __cputchar);
134 
135 	if ((curscr != NULL) && (curscr->flags & __KEYPAD))
136 		(void) tputs(__tc_ke, 0, __cputchar);
137 	(void) tputs(__tc_ve, 0, __cputchar);
138 	(void) tputs(__tc_te, 0, __cputchar);
139 	(void) fflush(_cursesi_screen->outfd);
140 	(void) setvbuf(_cursesi_screen->outfd, NULL, _IOLBF, (size_t) 0);
141 
142 	_cursesi_screen->endwin = 1;
143 
144 	return (tcsetattr(fileno(_cursesi_screen->infd),
145 			  __tcaction ? TCSASOFT | TCSADRAIN : TCSADRAIN,
146 			  &_cursesi_screen->orig_termios) ? ERR : OK);
147 }
148 
149 
150 void
151 __restartwin(void)
152 {
153 	if (!_cursesi_screen->endwin)
154 		return;
155 
156 	/* Reset the curses SIGTSTP signal handler. */
157 	__set_stophandler();
158 
159 	/* save the new "default" terminal state */
160 	(void) tcgetattr(fileno(_cursesi_screen->infd),
161 			 &_cursesi_screen->orig_termios);
162 
163 	/* Reset the terminal state to the mode just before we stopped. */
164 	(void) tcsetattr(fileno(_cursesi_screen->infd),
165 			 __tcaction ? TCSASOFT | TCSADRAIN : TCSADRAIN,
166 			 &_cursesi_screen->save_termios);
167 
168 	/* Restore colours */
169 	__restore_colors();
170 
171 	/* Reset meta */
172 	__restore_meta_state();
173 
174 	/* Restart the screen. */
175 	__startwin(_cursesi_screen);
176 
177 	/* Reset cursor visibility */
178 	__restore_cursor_vis();
179 
180 	/* Repaint the screen. */
181 	wrefresh(curscr);
182 }
183 
184 int
185 def_prog_mode(void)
186 {
187 	if (_cursesi_screen->endwin)
188 		return ERR;
189 
190 	return (tcgetattr(fileno(_cursesi_screen->infd),
191 			  &_cursesi_screen->save_termios) ? ERR : OK);
192 }
193 
194 int
195 reset_prog_mode(void)
196 {
197 
198 	return tcsetattr(fileno(_cursesi_screen->infd),
199 			 __tcaction ? TCSASOFT | TCSADRAIN : TCSADRAIN,
200 			 &_cursesi_screen->save_termios) ? ERR : OK;
201 }
202 
203 int
204 def_shell_mode(void)
205 {
206 	return (tcgetattr(fileno(_cursesi_screen->infd),
207 			  &_cursesi_screen->orig_termios) ? ERR : OK);
208 }
209 
210 int
211 reset_shell_mode(void)
212 {
213 	return (__stopwin());
214 }
215