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tstp.c revision 1.37 
      1 /*	$NetBSD: tstp.c,v 1.37 2009/07/22 16:57:15 roy 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 1.37 2009/07/22 16:57:15 roy Exp $");
     38 #endif
     39 #endif				/* not lint */
     40 
     41 #include <sys/ioctl.h>
     42 
     43 #include <errno.h>
     44 #include <signal.h>
     45 #include <termios.h>
     46 #include <unistd.h>
     47 
     48 #include "curses.h"
     49 #include "curses_private.h"
     50 
     51 static int tstp_set = 0;
     52 static int winch_set = 0;
     53 
     54 static void (*otstpfn)
     55 __P((int)) = SIG_DFL;
     56 
     57 static struct sigaction	owsa;
     58 
     59 /*
     60  * stop_signal_handler --
     61  *	Handle stop signals.
     62  */
     63 void
     64 __stop_signal_handler(/*ARGSUSED*/int signo)
     65 {
     66 	sigset_t oset, set;
     67 
     68 	/*
     69 	 * Block window change and timer signals.  The latter is because
     70 	 * applications use timers to decide when to repaint the screen.
     71 	 */
     72 	(void) sigemptyset(&set);
     73 	(void) sigaddset(&set, SIGALRM);
     74 	(void) sigaddset(&set, SIGWINCH);
     75 	(void) sigprocmask(SIG_BLOCK, &set, &oset);
     76 
     77 	/*
     78 	 * End the window, which also resets the terminal state to the
     79 	 * original modes.
     80 	 */
     81 	__stopwin();
     82 
     83 	/* Unblock SIGTSTP. */
     84 	(void) sigemptyset(&set);
     85 	(void) sigaddset(&set, SIGTSTP);
     86 	(void) sigprocmask(SIG_UNBLOCK, &set, NULL);
     87 
     88 	/* Stop ourselves. */
     89 	(void) kill(0, SIGTSTP);
     90 
     91 	/* Time passes ... */
     92 
     93 	/* restart things */
     94 	__restartwin();
     95 
     96 	/* Reset the signals. */
     97 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
     98 }
     99 
    100 /*
    101  * Set the TSTP handler.
    102  */
    103 void
    104 __set_stophandler(void)
    105 {
    106 #ifdef DEBUG
    107 	__CTRACE(__CTRACE_MISC, "__set_stophandler: %d\n", tstp_set);
    108 #endif
    109 	if (!tstp_set) {
    110 		otstpfn = signal(SIGTSTP, __stop_signal_handler);
    111 		tstp_set = 1;
    112 	}
    113 }
    114 
    115 /*
    116  * Restore the TSTP handler.
    117  */
    118 void
    119 __restore_stophandler(void)
    120 {
    121 #ifdef DEBUG
    122 	__CTRACE(__CTRACE_MISC, "__restore_stophandler: %d\n", tstp_set);
    123 #endif
    124 	if (tstp_set) {
    125 		(void) signal(SIGTSTP, otstpfn);
    126 		tstp_set = 0;
    127 	}
    128 }
    129 
    130 /*
    131  * winch_signal_handler --
    132  *	Handle winch signals by pushing KEY_RESIZE into the input stream.
    133  */
    134 void
    135 __winch_signal_handler(/*ARGSUSED*/int signo)
    136 {
    137 	struct winsize win;
    138 
    139 	if (ioctl(fileno(_cursesi_screen->outfd), TIOCGWINSZ, &win) != -1 &&
    140 	    win.ws_row != 0 && win.ws_col != 0) {
    141 		LINES = win.ws_row;
    142 		COLS = win.ws_col;
    143 	}
    144 	/*
    145 	 * If there was a previous handler, call that,
    146 	 * otherwise tell getch() to send KEY_RESIZE.
    147 	 */
    148 	if (owsa.sa_handler !=  NULL)
    149 		owsa.sa_handler(signo);
    150 	else
    151 		_cursesi_screen->resized = 1;
    152 }
    153 
    154 /*
    155  * Set the WINCH handler.
    156  */
    157 void
    158 __set_winchhandler(void)
    159 {
    160 #ifdef DEBUG
    161 	__CTRACE(__CTRACE_MISC, "__set_winchhandler: %d\n", winch_set);
    162 #endif
    163 	if (!winch_set) {
    164 		struct sigaction sa;
    165 
    166 		sa.sa_handler = __winch_signal_handler;
    167 		sa.sa_flags = 0;
    168 		sigemptyset(&sa.sa_mask);
    169 		sigaction(SIGWINCH, &sa, &owsa);
    170 		winch_set = 1;
    171 #ifdef DEBUG
    172 		__CTRACE(__CTRACE_MISC,
    173 		    "__set_winchhandler: owsa.sa_handler=%p\n",
    174 		    owsa.sa_handler);
    175 #endif
    176 	}
    177 }
    178 
    179 /*
    180  * Restore the WINCH handler.
    181  */
    182 void
    183 __restore_winchhandler(void)
    184 {
    185 #ifdef DEBUG
    186 	__CTRACE(__CTRACE_MISC, "__restore_winchhandler: %d\n", winch_set);
    187 #endif
    188 	if (winch_set > 0) {
    189 		struct sigaction cwsa;
    190 
    191 		sigaction(SIGWINCH, NULL, &cwsa);
    192 		if (cwsa.sa_handler == owsa.sa_handler) {
    193 			sigaction(SIGWINCH, &owsa, NULL);
    194 			winch_set = 0;
    195 		} else {
    196 			/*
    197 			 * We're now using the programs WINCH handler,
    198 			 * so don't restore the previous one.
    199 			 */
    200 			winch_set = -1;
    201 #ifdef DEBUG
    202 			__CTRACE(__CTRACE_MISC, "cwsa.sa_handler = %p\n",
    203 			    cwsa.sa_handler);
    204 #endif
    205 		}
    206 	}
    207 }
    208 
    209 /* To allow both SIGTSTP and endwin() to come back nicely, we provide
    210    the following routines. */
    211 
    212 int
    213 __stopwin(void)
    214 {
    215 #ifdef DEBUG
    216 	__CTRACE(__CTRACE_MISC, "__stopwin\n");
    217 #endif
    218 	if (_cursesi_screen->endwin)
    219 		return OK;
    220 
    221 	/* Get the current terminal state (which the user may have changed). */
    222 	(void) tcgetattr(fileno(_cursesi_screen->infd),
    223 			 &_cursesi_screen->save_termios);
    224 
    225 	__restore_stophandler();
    226 	__restore_winchhandler();
    227 
    228 	if (curscr != NULL) {
    229 		__unsetattr(0);
    230 		__mvcur((int) curscr->cury, (int) curscr->curx,
    231 		    (int) curscr->maxy - 1, 0, 0);
    232 	}
    233 
    234 	if (__tc_mo != NULL)
    235 		(void) tputs(__tc_mo, 0, __cputchar);
    236 
    237 	if ((curscr != NULL) && (curscr->flags & __KEYPAD))
    238 		(void) tputs(__tc_ke, 0, __cputchar);
    239 	(void) tputs(__tc_ve, 0, __cputchar);
    240 	(void) tputs(__tc_te, 0, __cputchar);
    241 	(void) fflush(_cursesi_screen->outfd);
    242 	(void) setvbuf(_cursesi_screen->outfd, NULL, _IOLBF, (size_t) 0);
    243 
    244 	_cursesi_screen->endwin = 1;
    245 
    246 	return (tcsetattr(fileno(_cursesi_screen->infd),
    247 			  __tcaction ? TCSASOFT | TCSADRAIN : TCSADRAIN,
    248 			  &_cursesi_screen->orig_termios) ? ERR : OK);
    249 }
    250 
    251 
    252 void
    253 __restartwin(void)
    254 {
    255 	struct winsize win;
    256 	int nlines, ncols;
    257 
    258 #ifdef DEBUG
    259 	__CTRACE(__CTRACE_MISC, "__restartwin\n");
    260 #endif
    261 	if (!_cursesi_screen->endwin)
    262 		return;
    263 
    264 	/* Reset the curses SIGTSTP and SIGWINCH signal handlers. */
    265 	__set_stophandler();
    266 	__set_winchhandler();
    267 
    268 	/*
    269 	 * Check to see if the window size has changed.
    270 	 * If the application didn't update LINES and COLS,
    271 	 * set the * resized flag to tell getch() to push KEY_RESIZE.
    272 	 * Update curscr (which also updates __virtscr) and stdscr
    273 	 * to match the new size.
    274 	 */
    275 	if (ioctl(fileno(_cursesi_screen->outfd), TIOCGWINSZ, &win) != -1 &&
    276 	    win.ws_row != 0 && win.ws_col != 0) {
    277 		if (win.ws_row != LINES) {
    278 			LINES = win.ws_row;
    279 			_cursesi_screen->resized = 1;
    280 		}
    281 		if (win.ws_col != COLS) {
    282 			COLS = win.ws_col;
    283 			_cursesi_screen->resized = 1;
    284 		}
    285 	}
    286 	/*
    287 	 * We need to make local copies of LINES and COLS, otherwise we
    288 	 * could lose if they are changed between wresize() calls.
    289 	 */
    290 	nlines = LINES;
    291 	ncols = COLS;
    292 	if (curscr->maxy != nlines || curscr->maxx != ncols)
    293 		wresize(curscr, nlines, ncols);
    294 	if (stdscr->maxy != nlines || stdscr->maxx != ncols)
    295 		wresize(stdscr, nlines, ncols);
    296 
    297 	/* save the new "default" terminal state */
    298 	(void) tcgetattr(fileno(_cursesi_screen->infd),
    299 			 &_cursesi_screen->orig_termios);
    300 
    301 	/* Reset the terminal state to the mode just before we stopped. */
    302 	(void) tcsetattr(fileno(_cursesi_screen->infd),
    303 			 __tcaction ? TCSASOFT | TCSADRAIN : TCSADRAIN,
    304 			 &_cursesi_screen->save_termios);
    305 
    306 	/* Restore colours */
    307 	__restore_colors();
    308 
    309 	/* Reset meta */
    310 	__restore_meta_state();
    311 
    312 	/* Restart the screen. */
    313 	__startwin(_cursesi_screen);
    314 
    315 	/* Reset cursor visibility */
    316 	__restore_cursor_vis();
    317 
    318 	/* Repaint the screen. */
    319 	wrefresh(curscr);
    320 }
    321 
    322 int
    323 def_prog_mode(void)
    324 {
    325 	if (_cursesi_screen->endwin)
    326 		return ERR;
    327 
    328 	return (tcgetattr(fileno(_cursesi_screen->infd),
    329 			  &_cursesi_screen->save_termios) ? ERR : OK);
    330 }
    331 
    332 int
    333 reset_prog_mode(void)
    334 {
    335 
    336 	return tcsetattr(fileno(_cursesi_screen->infd),
    337 			 __tcaction ? TCSASOFT | TCSADRAIN : TCSADRAIN,
    338 			 &_cursesi_screen->save_termios) ? ERR : OK;
    339 }
    340 
    341 int
    342 def_shell_mode(void)
    343 {
    344 	return (tcgetattr(fileno(_cursesi_screen->infd),
    345 			  &_cursesi_screen->orig_termios) ? ERR : OK);
    346 }
    347 
    348 int
    349 reset_shell_mode(void)
    350 {
    351 	return (__stopwin());
    352 }
    353