lib/libcurses/tstp.c

   1 /*      $NetBSD: tstp.c,v 1.38 2010/02/03 15:34:40 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 1.38 2010/02/03 15:34:40 roy Exp $");
  38 #endif
  39 #endif                          /* not lint */
  40
  41 #ifndef TCSASOFT
  42 #define TCSASOFT 0
  43 #endif
  44
  45 #include <sys/ioctl.h>
  46
  47 #include <errno.h>
  48 #include <signal.h>
  49 #include <termios.h>
  50 #include <unistd.h>
  51
  52 #include "curses.h"
  53 #include "curses_private.h"
  54
  55 static int tstp_set = 0;
  56 static int winch_set = 0;
  57
  58 static void (*otstpfn)
  59 __P((int)) = SIG_DFL;
  60
  61 static struct sigaction owsa;
  62
  63 /*
  64  * stop_signal_handler --
  65  *      Handle stop signals.
  66  */
  67 void
  68 __stop_signal_handler(/*ARGSUSED*/int signo)
  69 {
  70         sigset_t oset, set;
  71
  72         /*
  73          * Block window change and timer signals.  The latter is because
  74          * applications use timers to decide when to repaint the screen.
  75          */
  76         (void) sigemptyset(&set);
  77         (void) sigaddset(&set, SIGALRM);
  78         (void) sigaddset(&set, SIGWINCH);
  79         (void) sigprocmask(SIG_BLOCK, &set, &oset);
  80
  81         /*
  82          * End the window, which also resets the terminal state to the
  83          * original modes.
  84          */
  85         __stopwin();
  86
  87         /* Unblock SIGTSTP. */
  88         (void) sigemptyset(&set);
  89         (void) sigaddset(&set, SIGTSTP);
  90         (void) sigprocmask(SIG_UNBLOCK, &set, NULL);
  91
  92         /* Stop ourselves. */
  93         (void) kill(0, SIGTSTP);
  94
  95         /* Time passes ... */
  96
  97         /* restart things */
  98         __restartwin();
  99
 100         /* Reset the signals. */
 101         (void) sigprocmask(SIG_SETMASK, &oset, NULL);
 102 }
 103
 104 /*
 105  * Set the TSTP handler.
 106  */
 107 void
 108 __set_stophandler(void)
 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 #ifdef DEBUG
 126         __CTRACE(__CTRACE_MISC, "__restore_stophandler: %d\n", tstp_set);
 127 #endif
 128         if (tstp_set) {
 129                 (void) signal(SIGTSTP, otstpfn);
 130                 tstp_set = 0;
 131         }
 132 }
 133
 134 /*
 135  * winch_signal_handler --
 136  *      Handle winch signals by pushing KEY_RESIZE into the input stream.
 137  */
 138 void
 139 __winch_signal_handler(/*ARGSUSED*/int signo)
 140 {
 141         struct winsize win;
 142
 143         if (ioctl(fileno(_cursesi_screen->outfd), TIOCGWINSZ, &win) != -1 &&
 144             win.ws_row != 0 && win.ws_col != 0) {
 145                 LINES = win.ws_row;
 146                 COLS = win.ws_col;
 147         }
 148         /*
 149          * If there was a previous handler, call that,
 150          * otherwise tell getch() to send KEY_RESIZE.
 151          */
 152         if (owsa.sa_handler !=  NULL)
 153                 owsa.sa_handler(signo);
 154         else
 155                 _cursesi_screen->resized = 1;
 156 }
 157
 158 /*
 159  * Set the WINCH handler.
 160  */
 161 void
 162 __set_winchhandler(void)
 163 {
 164 #ifdef DEBUG
 165         __CTRACE(__CTRACE_MISC, "__set_winchhandler: %d\n", winch_set);
 166 #endif
 167         if (!winch_set) {
 168                 struct sigaction sa;
 169
 170                 sa.sa_handler = __winch_signal_handler;
 171                 sa.sa_flags = 0;
 172                 sigemptyset(&sa.sa_mask);
 173                 sigaction(SIGWINCH, &sa, &owsa);
 174                 winch_set = 1;
 175 #ifdef DEBUG
 176                 __CTRACE(__CTRACE_MISC,
 177                     "__set_winchhandler: owsa.sa_handler=%p\n",
 178                     owsa.sa_handler);
 179 #endif
 180         }
 181 }
 182
 183 /*
 184  * Restore the WINCH handler.
 185  */
 186 void
 187 __restore_winchhandler(void)
 188 {
 189 #ifdef DEBUG
 190         __CTRACE(__CTRACE_MISC, "__restore_winchhandler: %d\n", winch_set);
 191 #endif
 192         if (winch_set > 0) {
 193                 struct sigaction cwsa;
 194
 195                 sigaction(SIGWINCH, NULL, &cwsa);
 196                 if (cwsa.sa_handler == owsa.sa_handler) {
 197                         sigaction(SIGWINCH, &owsa, NULL);
 198                         winch_set = 0;
 199                 } else {
 200                         /*
 201                          * We're now using the programs WINCH handler,
 202                          * so don't restore the previous one.
 203                          */
 204                         winch_set = -1;
 205 #ifdef DEBUG
 206                         __CTRACE(__CTRACE_MISC, "cwsa.sa_handler = %p\n",
 207                             cwsa.sa_handler);
 208 #endif
 209                 }
 210         }
 211 }
 212
 213 /* To allow both SIGTSTP and endwin() to come back nicely, we provide
 214    the following routines. */
 215
 216 int
 217 __stopwin(void)
 218 {
 219 #ifdef DEBUG
 220         __CTRACE(__CTRACE_MISC, "__stopwin\n");
 221 #endif
 222         if (_cursesi_screen->endwin)
 223                 return OK;
 224
 225         /* Get the current terminal state (which the user may have changed). */
 226         (void) tcgetattr(fileno(_cursesi_screen->infd),
 227                          &_cursesi_screen->save_termios);
 228
 229         __restore_stophandler();
 230         __restore_winchhandler();
 231
 232         if (curscr != NULL) {
 233                 __unsetattr(0);
 234                 __mvcur((int) curscr->cury, (int) curscr->curx,
 235                     (int) curscr->maxy - 1, 0, 0);
 236         }
 237
 238         if (meta_off != NULL)
 239                 (void) tputs(meta_off, 0, __cputchar);
 240
 241         if ((curscr != NULL) && (curscr->flags & __KEYPAD))
 242                 (void) tputs(keypad_local, 0, __cputchar);
 243         (void) tputs(cursor_normal, 0, __cputchar);
 244         (void) tputs(exit_ca_mode, 0, __cputchar);
 245         (void) fflush(_cursesi_screen->outfd);
 246         (void) setvbuf(_cursesi_screen->outfd, NULL, _IOLBF, (size_t) 0);
 247
 248         _cursesi_screen->endwin = 1;
 249
 250         return (tcsetattr(fileno(_cursesi_screen->infd),
 251                           __tcaction ? TCSASOFT | TCSADRAIN : TCSADRAIN,
 252                           &_cursesi_screen->orig_termios) ? ERR : OK);
 253 }
 254
 255
 256 void
 257 __restartwin(void)
 258 {
 259         struct winsize win;
 260         int nlines, ncols;
 261
 262 #ifdef DEBUG
 263         __CTRACE(__CTRACE_MISC, "__restartwin\n");
 264 #endif
 265         if (!_cursesi_screen->endwin)
 266                 return;
 267
 268         /* Reset the curses SIGTSTP and SIGWINCH signal handlers. */
 269         __set_stophandler();
 270         __set_winchhandler();
 271
 272         /*
 273          * Check to see if the window size has changed.
 274          * If the application didn't update LINES and COLS,
 275          * set the * resized flag to tell getch() to push KEY_RESIZE.
 276          * Update curscr (which also updates __virtscr) and stdscr
 277          * to match the new size.
 278          */
 279         if (ioctl(fileno(_cursesi_screen->outfd), TIOCGWINSZ, &win) != -1 &&
 280             win.ws_row != 0 && win.ws_col != 0) {
 281                 if (win.ws_row != LINES) {
 282                         LINES = win.ws_row;
 283                         _cursesi_screen->resized = 1;
 284                 }
 285                 if (win.ws_col != COLS) {
 286                         COLS = win.ws_col;
 287                         _cursesi_screen->resized = 1;
 288                 }
 289         }
 290         /*
 291          * We need to make local copies of LINES and COLS, otherwise we
 292          * could lose if they are changed between wresize() calls.
 293          */
 294         nlines = LINES;
 295         ncols = COLS;
 296         if (curscr->maxy != nlines || curscr->maxx != ncols)
 297                 wresize(curscr, nlines, ncols);
 298         if (stdscr->maxy != nlines || stdscr->maxx != ncols)
 299                 wresize(stdscr, nlines, ncols);
 300
 301         /* save the new "default" terminal state */
 302         (void) tcgetattr(fileno(_cursesi_screen->infd),
 303                          &_cursesi_screen->orig_termios);
 304
 305         /* Reset the terminal state to the mode just before we stopped. */
 306         (void) tcsetattr(fileno(_cursesi_screen->infd),
 307                          __tcaction ? TCSASOFT | TCSADRAIN : TCSADRAIN,
 308                          &_cursesi_screen->save_termios);
 309
 310         /* Restore colours */
 311         __restore_colors();
 312
 313         /* Reset meta */
 314         __restore_meta_state();
 315
 316         /* Restart the screen. */
 317         __startwin(_cursesi_screen);
 318
 319         /* Reset cursor visibility */
 320         __restore_cursor_vis();
 321
 322         /* Repaint the screen. */
 323         wrefresh(curscr);
 324 }
 325
 326 int
 327 def_prog_mode(void)
 328 {
 329         if (_cursesi_screen->endwin)
 330                 return ERR;
 331
 332         return (tcgetattr(fileno(_cursesi_screen->infd),
 333                           &_cursesi_screen->save_termios) ? ERR : OK);
 334 }
 335
 336 int
 337 reset_prog_mode(void)
 338 {
 339
 340         return tcsetattr(fileno(_cursesi_screen->infd),
 341                          __tcaction ? TCSASOFT | TCSADRAIN : TCSADRAIN,
 342                          &_cursesi_screen->save_termios) ? ERR : OK;
 343 }
 344
 345 int
 346 def_shell_mode(void)
 347 {
 348         return (tcgetattr(fileno(_cursesi_screen->infd),
 349                           &_cursesi_screen->orig_termios) ? ERR : OK);
 350 }
 351
 352 int
 353 reset_shell_mode(void)
 354 {
 355         return (__stopwin());
 356 }