Home | History | Annotate | Line # | Download | only in libcurses
tstp.c revision 1.11 
      1 /*	$NetBSD: tstp.c,v 1.11 1997/11/13 00:40:27 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 1.11 1997/11/13 00:40:27 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 	/* Reset the signals. */
     91 	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
     92 }
     93 
     94 static void (*otstpfn) __P((int)) = SIG_DFL;
     95 
     96 /*
     97  * Set the TSTP handler.
     98  */
     99 void
    100 __set_stophandler()
    101 {
    102 	otstpfn = signal(SIGTSTP, __stop_signal_handler);
    103 }
    104 
    105 /*
    106  * Restore the TSTP handler.
    107  */
    108 void
    109 __restore_stophandler()
    110 {
    111 	(void)signal(SIGTSTP, otstpfn);
    112 }
    113 
    114 
    115 /* To allow both SIGTSTP and endwin() to come back nicely, we provide
    116    the following routines. */
    117 
    118 static struct termios save_termios;
    119 
    120 int
    121 __stopwin()
    122 {
    123 	/* Get the current terminal state (which the user may have changed). */
    124 	(void)tcgetattr(STDIN_FILENO, &save_termios);
    125 
    126 	__restore_stophandler();
    127 
    128 	if (curscr != NULL) {
    129 		if (curscr->flags & __WSTANDOUT) {
    130 			tputs(SE, 0, __cputchar);
    131 			curscr->flags &= ~__WSTANDOUT;
    132 		}
    133 		__mvcur(curscr->cury, curscr->cury, curscr->maxy - 1, 0, 0);
    134 	}
    135 
    136 	(void)tputs(VE, 0, __cputchar);
    137 	(void)tputs(TE, 0, __cputchar);
    138 	(void)fflush(stdout);
    139 	(void)setvbuf(stdout, NULL, _IOLBF, 0);
    140 
    141 	return (tcsetattr(STDIN_FILENO, __tcaction ?
    142 	    TCSASOFT | TCSADRAIN : TCSADRAIN, &__orig_termios) ? ERR : OK);
    143 }
    144 
    145 
    146 void
    147 __restartwin()
    148 {
    149 	/* Reset the curses SIGTSTP signal handler. */
    150 	__set_stophandler();
    151 
    152 	/* save the new "default" terminal state */
    153 	(void)tcgetattr(STDIN_FILENO, &__orig_termios);
    154 
    155 	/* Reset the terminal state to the mode just before we stopped. */
    156 	(void)tcsetattr(STDIN_FILENO, __tcaction ?
    157 	    TCSASOFT | TCSADRAIN : TCSADRAIN, &save_termios);
    158 
    159 	/* Restart the screen. */
    160 	__startwin();
    161 
    162 	/* Repaint the screen. */
    163 	wrefresh(curscr);
    164 }
    165