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tstp.c revision 1.42.12.2 
      1 /*	$NetBSD: tstp.c,v 1.42.12.2 2018/10/20 06:58:22 pgoyette 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. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #ifndef lint
     34 #if 0
     35 static char sccsid[] = "@(#)tstp.c	8.3 (Berkeley) 5/4/94";
     36 #else
     37 __RCSID("$NetBSD: tstp.c,v 1.42.12.2 2018/10/20 06:58:22 pgoyette Exp $");
     38 #endif
     39 #endif				/* not lint */
     40 
     41 #include <sys/ioctl.h>
     42 #include <sys/param.h>
     43 
     44 #include <errno.h>
     45 #include <signal.h>
     46 #include <termios.h>
     47 #include <unistd.h>
     48 
     49 #include "curses.h"
     50 #include "curses_private.h"
     51 
     52 static int tstp_set;
     53 static int winch_set;
     54 
     55 static void (*otstpfn)(int) = SIG_DFL;
     56 
     57 static struct sigaction	owsa;
     58 #ifndef TCSASOFT
     59 #define TCSASOFT 0
     60 #endif
     61 
     62 /*
     63  * stop_signal_handler --
     64  *	Handle stop signals.
     65  */
     66 void
     67 __stop_signal_handler(/*ARGSUSED*/int signo)
     68 {
     69 	sigset_t oset, set;
     70 
     71 	/*
     72 	 * Block window change and timer signals.  The latter is because
     73 	 * applications use timers to decide when to repaint the screen.
     74 	 */
     75 	(void)sigemptyset(&set);
     76 	(void)sigaddset(&set, SIGALRM);
     77 	(void)sigaddset(&set, SIGWINCH);
     78 	(void)sigprocmask(SIG_BLOCK, &set, &oset);
     79 
     80 	/*
     81 	 * End the window, which also resets the terminal state to the
     82 	 * original modes.
     83 	 */
     84 	__stopwin();
     85 
     86 	/* Unblock SIGTSTP. */
     87 	(void)sigemptyset(&set);
     88 	(void)sigaddset(&set, SIGTSTP);
     89 	(void)sigprocmask(SIG_UNBLOCK, &set, NULL);
     90 
     91 	/* Stop ourselves. */
     92 	(void)kill(0, SIGTSTP);
     93 
     94 	/* Time passes ... */
     95 
     96 	/* restart things */
     97 	__restartwin();
     98 
     99 	/* Reset the signals. */
    100 	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
    101 }
    102 
    103 /*
    104  * Set the TSTP handler.
    105  */
    106 void
    107 __set_stophandler(void)
    108 {
    109 
    110 #ifdef DEBUG
    111 	__CTRACE(__CTRACE_MISC, "__set_stophandler: %d\n", tstp_set);
    112 #endif
    113 	if (!tstp_set) {
    114 		otstpfn = signal(SIGTSTP, __stop_signal_handler);
    115 		tstp_set = 1;
    116 	}
    117 }
    118 
    119 /*
    120  * Restore the TSTP handler.
    121  */
    122 void
    123 __restore_stophandler(void)
    124 {
    125 
    126 #ifdef DEBUG
    127 	__CTRACE(__CTRACE_MISC, "__restore_stophandler: %d\n", tstp_set);
    128 #endif
    129 	if (tstp_set) {
    130 		(void)signal(SIGTSTP, otstpfn);
    131 		tstp_set = 0;
    132 	}
    133 }
    134 
    135 /*
    136  * winch_signal_handler --
    137  *	Handle winch signals by pushing KEY_RESIZE into the input stream.
    138  */
    139 void
    140 __winch_signal_handler(/*ARGSUSED*/int signo)
    141 {
    142 	struct winsize win;
    143 
    144 	if (ioctl(fileno(_cursesi_screen->outfd), TIOCGWINSZ, &win) != -1 &&
    145 	    win.ws_row != 0 && win.ws_col != 0)
    146 	{
    147 		LINES = win.ws_row;
    148 		COLS = win.ws_col;
    149 	}
    150 	/*
    151 	 * If there was a previous handler, call that,
    152 	 * otherwise tell getch() to send KEY_RESIZE.
    153 	 */
    154 	if (owsa.sa_handler != SIG_DFL &&
    155 	    owsa.sa_handler != SIG_IGN &&
    156 	    owsa.sa_handler != SIG_ERR &&
    157 	    owsa.sa_handler != SIG_HOLD)
    158 		owsa.sa_handler(signo);
    159 	else
    160 		_cursesi_screen->resized = 1;
    161 }
    162 
    163 /*
    164  * Set the WINCH handler.
    165  */
    166 void
    167 __set_winchhandler(void)
    168 {
    169 
    170 #ifdef DEBUG
    171 	__CTRACE(__CTRACE_MISC, "__set_winchhandler: %d\n", winch_set);
    172 #endif
    173 	if (!winch_set) {
    174 		struct sigaction sa;
    175 
    176 		sa.sa_handler = __winch_signal_handler;
    177 		sa.sa_flags = 0;
    178 		sigemptyset(&sa.sa_mask);
    179 		sigaction(SIGWINCH, &sa, &owsa);
    180 		winch_set = 1;
    181 #ifdef DEBUG
    182 		__CTRACE(__CTRACE_MISC,
    183 		    "__set_winchhandler: owsa.sa_handler=%p\n",
    184 		    owsa.sa_handler);
    185 #endif
    186 	}
    187 }
    188 
    189 /*
    190  * Restore the WINCH handler.
    191  */
    192 void
    193 __restore_winchhandler(void)
    194 {
    195 
    196 #ifdef DEBUG
    197 	__CTRACE(__CTRACE_MISC, "__restore_winchhandler: %d\n", winch_set);
    198 #endif
    199 	if (winch_set > 0) {
    200 		struct sigaction cwsa;
    201 
    202 		sigaction(SIGWINCH, NULL, &cwsa);
    203 		if (cwsa.sa_handler == owsa.sa_handler) {
    204 			sigaction(SIGWINCH, &owsa, NULL);
    205 			winch_set = 0;
    206 		} else {
    207 			/*
    208 			 * We're now using the programs WINCH handler,
    209 			 * so don't restore the previous one.
    210 			 */
    211 			winch_set = -1;
    212 #ifdef DEBUG
    213 			__CTRACE(__CTRACE_MISC, "cwsa.sa_handler = %p\n",
    214 			    cwsa.sa_handler);
    215 #endif
    216 		}
    217 	}
    218 }
    219 
    220 /* To allow both SIGTSTP and endwin() to come back nicely, we provide
    221    the following routines. */
    222 
    223 int
    224 __stopwin(void)
    225 {
    226 
    227 #ifdef DEBUG
    228 	__CTRACE(__CTRACE_MISC, "__stopwin\n");
    229 #endif
    230 	if (_cursesi_screen == NULL)
    231 		return ERR;
    232 	if (_cursesi_screen->endwin)
    233 		return OK;
    234 
    235 	/* Get the current terminal state (which the user may have changed). */
    236 	(void)tcgetattr(fileno(_cursesi_screen->infd),
    237 			&_cursesi_screen->save_termios);
    238 
    239 	__restore_stophandler();
    240 	__restore_winchhandler();
    241 
    242 	if (curscr != NULL) {
    243 		__unsetattr(0);
    244 		__mvcur((int)curscr->cury, (int)curscr->curx,
    245 		    (int)curscr->maxy - 1, 0, 0);
    246 	}
    247 
    248 	if (meta_on != NULL)
    249 		(void)tputs(meta_on, 0, __cputchar);
    250 
    251 	if ((curscr != NULL) && (curscr->flags & __KEYPAD))
    252 		(void)tputs(keypad_local, 0, __cputchar);
    253 	(void)tputs(cursor_normal, 0, __cputchar);
    254 	(void)tputs(exit_ca_mode, 0, __cputchar);
    255 	(void)fflush(_cursesi_screen->outfd);
    256 #ifdef BSD
    257 	(void)setvbuf(_cursesi_screen->outfd, NULL, _IOLBF, 0);
    258 #endif
    259 
    260 	_cursesi_screen->endwin = 1;
    261 
    262 	return tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSADRAIN,
    263 	    &_cursesi_screen->orig_termios) ? ERR : OK;
    264 }
    265 
    266 void
    267 __restartwin(void)
    268 {
    269 	struct winsize win;
    270 	int nlines, ncols;
    271 
    272 #ifdef DEBUG
    273 	__CTRACE(__CTRACE_MISC, "__restartwin\n");
    274 #endif
    275 	if (!_cursesi_screen->endwin)
    276 		return;
    277 
    278 	/* Reset the curses SIGTSTP and SIGWINCH signal handlers. */
    279 	__set_stophandler();
    280 	__set_winchhandler();
    281 
    282 	/*
    283 	 * Check to see if the window size has changed.
    284 	 * If the application didn't update LINES and COLS,
    285 	 * set the * resized flag to tell getch() to push KEY_RESIZE.
    286 	 * Update curscr (which also updates __virtscr) and stdscr
    287 	 * to match the new size.
    288 	 */
    289 	if (ioctl(fileno(_cursesi_screen->outfd), TIOCGWINSZ, &win) != -1 &&
    290 	    win.ws_row != 0 && win.ws_col != 0)
    291 	{
    292 		if (win.ws_row != LINES) {
    293 			LINES = win.ws_row;
    294 			_cursesi_screen->resized = 1;
    295 		}
    296 		if (win.ws_col != COLS) {
    297 			COLS = win.ws_col;
    298 			_cursesi_screen->resized = 1;
    299 		}
    300 	}
    301 	/*
    302 	 * We need to make local copies of LINES and COLS, otherwise we
    303 	 * could lose if they are changed between wresize() calls.
    304 	 */
    305 	nlines = LINES;
    306 	ncols = COLS;
    307 	if (curscr->maxy != nlines || curscr->maxx != ncols)
    308 		wresize(curscr, nlines, ncols);
    309 	if (stdscr->maxy != nlines || stdscr->maxx != ncols)
    310 		wresize(stdscr, nlines, ncols);
    311 
    312 	/* save the new "default" terminal state */
    313 	(void)tcgetattr(fileno(_cursesi_screen->infd),
    314 			&_cursesi_screen->orig_termios);
    315 
    316 	/* Reset the terminal state to the mode just before we stopped. */
    317 	(void)tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSADRAIN,
    318 			&_cursesi_screen->save_termios);
    319 
    320 	/* Restore colours */
    321 	__restore_colors();
    322 
    323 	/* Reset meta */
    324 	__restore_meta_state();
    325 
    326 	/* Restart the screen. */
    327 	__startwin(_cursesi_screen);
    328 
    329 	/* Reset cursor visibility */
    330 	__restore_cursor_vis();
    331 
    332 	/* Repaint the screen. */
    333 	wrefresh(curscr);
    334 }
    335 
    336 int
    337 def_prog_mode(void)
    338 {
    339 
    340 	if (_cursesi_screen->endwin)
    341 		return ERR;
    342 
    343 	return tcgetattr(fileno(_cursesi_screen->infd),
    344 			 &_cursesi_screen->save_termios) ? ERR : OK;
    345 }
    346 
    347 int
    348 reset_prog_mode(void)
    349 {
    350 
    351 	return tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSADRAIN,
    352 			 &_cursesi_screen->save_termios) ? ERR : OK;
    353 }
    354 
    355 int
    356 def_shell_mode(void)
    357 {
    358 
    359 	return tcgetattr(fileno(_cursesi_screen->infd),
    360 			 &_cursesi_screen->orig_termios) ? ERR : OK;
    361 }
    362 
    363 int
    364 reset_shell_mode(void)
    365 {
    366 
    367 	return __stopwin();
    368 }
    369