Home | History | Annotate | Line # | Download | only in libcurses
tstp.c revision 1.10 
      1 /*	$NetBSD: tstp.c,v 1.10 1997/09/12 21:08:25 phil 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 1.10 1997/09/12 21:08:25 phil 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 
     52 /*
     53  * stop_signal_handler --
     54  *	Handle stop signals.
     55  */
     56 void
     57 __stop_signal_handler(signo)
     58 	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 	/* Repaint the screen. */
     91 	wrefresh(curscr);
     92 
     93 	/* Reset the signals. */
     94 	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
     95 }
     96 
     97 static void (*otstpfn) __P((int)) = SIG_DFL;
     98 
     99 /*
    100  * Set the TSTP handler.
    101  */
    102 void
    103 __set_stophandler()
    104 {
    105 	otstpfn = signal(SIGTSTP, __stop_signal_handler);
    106 }
    107 
    108 /*
    109  * Restore the TSTP handler.
    110  */
    111 void
    112 __restore_stophandler()
    113 {
    114 	(void)signal(SIGTSTP, otstpfn);
    115 }
    116 
    117 
    118 /* To allow both SIGTSTP and endwin() to come back nicely, we provide
    119    the following routines. */
    120 
    121 static struct termios save;
    122 
    123 int
    124 __stopwin()
    125 {
    126 	/* Get the current terminal state (which the user may have changed). */
    127 	(void)tcgetattr(STDIN_FILENO, &save);
    128 
    129 	__restore_stophandler();
    130 
    131 	if (curscr != NULL) {
    132 		if (curscr->flags & __WSTANDOUT) {
    133 			tputs(SE, 0, __cputchar);
    134 			curscr->flags &= ~__WSTANDOUT;
    135 		}
    136 		__mvcur(curscr->cury, curscr->cury, curscr->maxy - 1, 0, 0);
    137 	}
    138 
    139 	(void)tputs(VE, 0, __cputchar);
    140 	(void)tputs(TE, 0, __cputchar);
    141 	(void)fflush(stdout);
    142 	(void)setvbuf(stdout, NULL, _IOLBF, 0);
    143 
    144 	return (tcsetattr(STDIN_FILENO, __tcaction ?
    145 	    TCSASOFT | TCSADRAIN : TCSADRAIN, &__orig_termios) ? ERR : OK);
    146 }
    147 
    148 
    149 void
    150 __restartwin()
    151 {
    152 	/* Reset the curses SIGTSTP signal handler. */
    153 	__set_stophandler();
    154 
    155 	/* save the new "default" terminal state */
    156 	(void)tcgetattr(STDIN_FILENO, &__orig_termios);
    157 
    158 	/* Reset the terminal state to the mode just before we stopped. */
    159 	(void)tcsetattr(STDIN_FILENO, __tcaction ?
    160 	    TCSASOFT | TCSADRAIN : TCSADRAIN, &save);
    161 
    162 	/* Restart the screen. */
    163 	__startwin();
    164 }
    165