xref: /netbsd-src/lib/libcurses/tstp.c (revision 3b01aba77a7a698587faaae455bbfe740923c1f5)
1 /*	$NetBSD: tstp.c,v 1.23 2001/01/14 08:12:47 blymn 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 #if 0
39 static char sccsid[] = "@(#)tstp.c	8.3 (Berkeley) 5/4/94";
40 #else
41 __RCSID("$NetBSD: tstp.c,v 1.23 2001/01/14 08:12:47 blymn Exp $");
42 #endif
43 #endif				/* not lint */
44 
45 #include <errno.h>
46 #include <signal.h>
47 #include <termios.h>
48 #include <unistd.h>
49 
50 #include "curses.h"
51 #include "curses_private.h"
52 
53 /*
54  * stop_signal_handler --
55  *	Handle stop signals.
56  */
57 void
58 __stop_signal_handler(/*ARGSUSED*/int signo)
59 {
60 	sigset_t oset, set;
61 
62 	/*
63 	 * Block window change and timer signals.  The latter is because
64 	 * applications use timers to decide when to repaint the screen.
65 	 */
66 	(void) sigemptyset(&set);
67 	(void) sigaddset(&set, SIGALRM);
68 	(void) sigaddset(&set, SIGWINCH);
69 	(void) sigprocmask(SIG_BLOCK, &set, &oset);
70 
71 	/*
72 	 * End the window, which also resets the terminal state to the
73 	 * original modes.
74 	 */
75 	__stopwin();
76 
77 	/* Unblock SIGTSTP. */
78 	(void) sigemptyset(&set);
79 	(void) sigaddset(&set, SIGTSTP);
80 	(void) sigprocmask(SIG_UNBLOCK, &set, NULL);
81 
82 	/* Stop ourselves. */
83 	(void) kill(0, SIGTSTP);
84 
85 	/* Time passes ... */
86 
87 	/* restart things */
88 	__restartwin();
89 
90 	/* Reset the signals. */
91 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
92 }
93 
94 static void (*otstpfn)
95 __P((int)) = SIG_DFL;
96 
97 /*
98  * Set the TSTP handler.
99  */
100 void
101 __set_stophandler(void)
102 {
103 	otstpfn = signal(SIGTSTP, __stop_signal_handler);
104 }
105 
106 /*
107  * Restore the TSTP handler.
108  */
109 void
110 __restore_stophandler(void)
111 {
112 	(void) signal(SIGTSTP, otstpfn);
113 }
114 
115 
116 /* To allow both SIGTSTP and endwin() to come back nicely, we provide
117    the following routines. */
118 
119 static struct termios save_termios;
120 
121 int
122 __stopwin(void)
123 {
124 	/* Get the current terminal state (which the user may have changed). */
125 	(void) tcgetattr(STDIN_FILENO, &save_termios);
126 
127 	__restore_stophandler();
128 
129 	if (curscr != NULL) {
130 		__unsetattr(0);
131 		__mvcur((int) curscr->cury, (int) curscr->curx, (int) curscr->maxy - 1, 0, 0);
132 	}
133 
134 	if (__tc_mo != NULL)
135 		(void) tputs(__tc_mo, 0, __cputchar);
136 
137 	if ((curscr != NULL) && (curscr->flags & __KEYPAD))
138 		(void) tputs(__tc_ke, 0, __cputchar);
139 	(void) tputs(__tc_ve, 0, __cputchar);
140 	(void) tputs(__tc_te, 0, __cputchar);
141 	(void) fflush(stdout);
142 	(void) setvbuf(stdout, NULL, _IOLBF, (size_t) 0);
143 
144 	__endwin = 1;
145 
146 	return (tcsetattr(STDIN_FILENO, __tcaction ?
147 	    TCSASOFT | TCSADRAIN : TCSADRAIN, &__orig_termios) ? ERR : OK);
148 }
149 
150 
151 void
152 __restartwin(void)
153 {
154 	/* Reset the curses SIGTSTP signal handler. */
155 	__set_stophandler();
156 
157 	/* save the new "default" terminal state */
158 	(void) tcgetattr(STDIN_FILENO, &__orig_termios);
159 
160 	/* Reset the terminal state to the mode just before we stopped. */
161 	(void) tcsetattr(STDIN_FILENO, __tcaction ?
162 	    TCSASOFT | TCSADRAIN : TCSADRAIN, &save_termios);
163 
164 	/* Restore colours */
165 	__restore_colors();
166 
167 	/* Reset meta */
168 	__restore_meta_state();
169 
170 	/* Reset cursor visibility */
171 	__restore_cursor_vis();
172 
173 	/* Restart the screen. */
174 	__startwin();
175 
176 	/* Repaint the screen. */
177 	wrefresh(curscr);
178 }
179 
180 int
181 def_prog_mode(void)
182 {
183 	return (tcgetattr(STDIN_FILENO, &save_termios) ? ERR : OK);
184 }
185 
186 int
187 reset_prog_mode(void)
188 {
189 	__restartwin();
190 	return(OK);
191 }
192 
193 int
194 def_shell_mode(void)
195 {
196 	return (tcgetattr(STDIN_FILENO, &__orig_termios) ? ERR : OK);
197 }
198 
199 int
200 reset_shell_mode(void)
201 {
202 	return (__stopwin());
203 }
204