[unix-history] / lib / libcurses / tstp.c

/*
 * Copyright (c) 1981, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char sccsid[] = "@(#)tstp.c	8.2 (Berkeley) 1/2/94";
#endif /* not lint */

#include <curses.h>
#include <errno.h>
#include <signal.h>
#include <termios.h>
#include <unistd.h>


/*
 * stop_signal_handler --
 *	Handle stop signals.
 */
void
__stop_signal_handler(signo)
	int signo;
{
	struct termios save;
	sigset_t oset, set;

	/* Get the current terminal state (which the user may have changed). */
	if (tcgetattr(STDIN_FILENO, &save))
		return;

	/*
	 * Block window change and timer signals.  The latter is because
	 * applications use timers to decide when to repaint the screen.
	 */
	(void)sigemptyset(&set);
	(void)sigaddset(&set, SIGALRM);
	(void)sigaddset(&set, SIGWINCH);
	(void)sigprocmask(SIG_BLOCK, &set, &oset);
	
	/*
	 * End the window, which also resets the terminal state to the
	 * original modes.
	 */
	endwin();

	/* Unblock SIGTSTP. */
	(void)sigemptyset(&set);
	(void)sigaddset(&set, SIGTSTP);
	(void)sigprocmask(SIG_UNBLOCK, &set, NULL);

	/* Stop ourselves. */
	__restore_stophandler();
	(void)kill(0, SIGTSTP);

	/* Time passes ... */

	/* Reset the curses SIGTSTP signal handler. */
	__set_stophandler();

	/* save the new "default" terminal state */
	(void)tcgetattr(STDIN_FILENO, &__orig_termios);

	/* Reset the terminal state to the mode just before we stopped. */
	(void)tcsetattr(STDIN_FILENO, __tcaction ?
	    TCSASOFT | TCSADRAIN : TCSADRAIN, &save);

	/* Restart the screen. */
	__startwin();

	/* Repaint the screen. */
	wrefresh(curscr);

	/* Reset the signals. */
	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
}

static void (*otstpfn)() = SIG_DFL;

/*
 * Set the TSTP handler.
 */
void
__set_stophandler()
{
	otstpfn = signal(SIGTSTP, __stop_signal_handler);
}

/*
 * Restore the TSTP handler.
 */
void
__restore_stophandler()
{
	(void)signal(SIGTSTP, otstpfn);
}

/* For compatibility */

void tstp() { __stop_signal_handler(SIGTSTP); }
Commit	Line	Data
15637ed4	1	/*
b80b8de3 AC	2	* Copyright (c) 1981, 1993
b80b8de3 AC	3	* The Regents of the University of California. All rights reserved.
15637ed4 RG	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This product includes software developed by the University of
	16	* California, Berkeley and its contributors.
	17	* 4. Neither the name of the University nor the names of its contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*/
	33
	34	#ifndef lint
b80b8de3	35	static char sccsid[] = "@(#)tstp.c 8.2 (Berkeley) 1/2/94";
15637ed4 RG	36	#endif /* not lint */
15637ed4 RG	37
b80b8de3 AC	38	#include <curses.h>
	39	#include <errno.h>
	40	#include <signal.h>
	41	#include <termios.h>
	42	#include <unistd.h>
15637ed4	43
15637ed4 RG	44
15637ed4 RG	45	/*
b80b8de3 AC	46	* stop_signal_handler --
b80b8de3 AC	47	* Handle stop signals.
15637ed4 RG	48	*/
15637ed4 RG	49	void
b80b8de3 AC	50	__stop_signal_handler(signo)
	51	int signo;
	52	{
	53	struct termios save;
	54	sigset_t oset, set;
	55
	56	/* Get the current terminal state (which the user may have changed). */
	57	if (tcgetattr(STDIN_FILENO, &save))
	58	return;
	59
	60	/*
	61	* Block window change and timer signals. The latter is because
	62	* applications use timers to decide when to repaint the screen.
	63	*/
	64	(void)sigemptyset(&set);
	65	(void)sigaddset(&set, SIGALRM);
	66	(void)sigaddset(&set, SIGWINCH);
	67	(void)sigprocmask(SIG_BLOCK, &set, &oset);
	68
	69	/*
	70	* End the window, which also resets the terminal state to the
	71	* original modes.
	72	*/
15637ed4	73	endwin();
b80b8de3 AC	74
	75	/* Unblock SIGTSTP. */
	76	(void)sigemptyset(&set);
	77	(void)sigaddset(&set, SIGTSTP);
	78	(void)sigprocmask(SIG_UNBLOCK, &set, NULL);
	79
	80	/* Stop ourselves. */
	81	__restore_stophandler();
	82	(void)kill(0, SIGTSTP);
	83
	84	/* Time passes ... */
	85
	86	/* Reset the curses SIGTSTP signal handler. */
	87	__set_stophandler();
	88
	89	/* save the new "default" terminal state */
	90	(void)tcgetattr(STDIN_FILENO, &__orig_termios);
	91
	92	/* Reset the terminal state to the mode just before we stopped. */
	93	(void)tcsetattr(STDIN_FILENO, __tcaction ?
	94	TCSASOFT \| TCSADRAIN : TCSADRAIN, &save);
	95
	96	/* Restart the screen. */
	97	__startwin();
	98
	99	/* Repaint the screen. */
15637ed4	100	wrefresh(curscr);
b80b8de3 AC	101
	102	/* Reset the signals. */
	103	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
15637ed4	104	}
b80b8de3 AC	105
	106	static void (*otstpfn)() = SIG_DFL;
	107
	108	/*
	109	* Set the TSTP handler.
	110	*/
	111	void
	112	__set_stophandler()
	113	{
	114	otstpfn = signal(SIGTSTP, __stop_signal_handler);
	115	}
	116
	117	/*
	118	* Restore the TSTP handler.
	119	*/
	120	void
	121	__restore_stophandler()
	122	{
	123	(void)signal(SIGTSTP, otstpfn);
	124	}
	125
	126	/* For compatibility */
	127
	128	void tstp() { __stop_signal_handler(SIGTSTP); }