xref: /original-bsd/lib/libcurses/tstp.c (revision 3f14a87d)
1 /*
2  * Copyright (c) 1981 Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  */
7 
8 #ifndef lint
9 static char sccsid[] = "@(#)tstp.c	5.8 (Berkeley) 01/24/93";
10 #endif /* not lint */
11 
12 #include <curses.h>
13 #include <errno.h>
14 #include <signal.h>
15 #include <termios.h>
16 #include <unistd.h>
17 
18 /*
19  * stop_signal_handler --
20  *	Handle stop signals.
21  */
22 void
23 __stop_signal_handler(signo)
24 	int signo;
25 {
26 	struct termios save;
27 	sigset_t oset, set;
28 
29 	/* Get the current terminal state. */
30 	if (tcgetattr(STDIN_FILENO, &save))
31 		return;
32 
33 	/*
34 	 * Block every signal we can get our hands on.  This is because
35 	 * applications have timers going off that want to repaint the
36 	 * screen.
37 	 */
38 	(void)sigfillset(&set);
39 	(void)sigprocmask(SIG_BLOCK, &set, &oset);
40 
41 	/*
42 	 * End the window, which also resets the terminal state to the
43 	 * original modes.
44 	 */
45 	endwin();
46 
47 	/* Unblock SIGTSTP. */
48 	(void)sigemptyset(&set);
49 	(void)sigaddset(&set, SIGTSTP);
50 	(void)sigprocmask(SIG_UNBLOCK, &set, NULL);
51 
52 	/* Stop ourselves. */
53 	(void)signal(SIGTSTP, SIG_DFL);
54 	(void)kill(0, SIGTSTP);
55 
56 	/* Time passes ... */
57 
58 	/* Reset the curses SIGTSTP signal handler. */
59 	(void)signal(SIGTSTP, __stop_signal_handler);
60 
61 	/* Reset the terminal state its mode when we stopped. */
62 	(void)tcsetattr(STDIN_FILENO, TCSADRAIN, &save);
63 
64 	/* Restart the screen. */
65 	__startwin();
66 
67 	/* Repaint the screen. */
68 	wrefresh(curscr);
69 
70 	/* Reset the signals. */
71 	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
72 }
73