lib/libcurses/tstp.c

   1 /*      $NetBSD: tstp.c,v 1.39 2011/08/29 11:07:38 christos 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 1.39 2011/08/29 11:07:38 christos 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 #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 #ifdef DEBUG
 110         __CTRACE(__CTRACE_MISC, "__set_stophandler: %d\n", tstp_set);
 111 #endif
 112         if (!tstp_set) {
 113                 otstpfn = signal(SIGTSTP, __stop_signal_handler);
 114                 tstp_set = 1;
 115         }
 116 }
 117
 118 /*
 119  * Restore the TSTP handler.
 120  */
 121 void
 122 __restore_stophandler(void)
 123 {
 124 #ifdef DEBUG
 125         __CTRACE(__CTRACE_MISC, "__restore_stophandler: %d\n", tstp_set);
 126 #endif
 127         if (tstp_set) {
 128                 (void) signal(SIGTSTP, otstpfn);
 129                 tstp_set = 0;
 130         }
 131 }
 132
 133 /*
 134  * winch_signal_handler --
 135  *      Handle winch signals by pushing KEY_RESIZE into the input stream.
 136  */
 137 void
 138 __winch_signal_handler(/*ARGSUSED*/int signo)
 139 {
 140         struct winsize win;
 141
 142         if (ioctl(fileno(_cursesi_screen->outfd), TIOCGWINSZ, &win) != -1 &&
 143             win.ws_row != 0 && win.ws_col != 0) {
 144                 LINES = win.ws_row;
 145                 COLS = win.ws_col;
 146         }
 147         /*
 148          * If there was a previous handler, call that,
 149          * otherwise tell getch() to send KEY_RESIZE.
 150          */
 151         if (owsa.sa_handler !=  NULL)
 152                 owsa.sa_handler(signo);
 153         else
 154                 _cursesi_screen->resized = 1;
 155 }
 156
 157 /*
 158  * Set the WINCH handler.
 159  */
 160 void
 161 __set_winchhandler(void)
 162 {
 163 #ifdef DEBUG
 164         __CTRACE(__CTRACE_MISC, "__set_winchhandler: %d\n", winch_set);
 165 #endif
 166         if (!winch_set) {
 167                 struct sigaction sa;
 168
 169                 sa.sa_handler = __winch_signal_handler;
 170                 sa.sa_flags = 0;
 171                 sigemptyset(&sa.sa_mask);
 172                 sigaction(SIGWINCH, &sa, &owsa);
 173                 winch_set = 1;
 174 #ifdef DEBUG
 175                 __CTRACE(__CTRACE_MISC,
 176                     "__set_winchhandler: owsa.sa_handler=%p\n",
 177                     owsa.sa_handler);
 178 #endif
 179         }
 180 }
 181
 182 /*
 183  * Restore the WINCH handler.
 184  */
 185 void
 186 __restore_winchhandler(void)
 187 {
 188 #ifdef DEBUG
 189         __CTRACE(__CTRACE_MISC, "__restore_winchhandler: %d\n", winch_set);
 190 #endif
 191         if (winch_set > 0) {
 192                 struct sigaction cwsa;
 193
 194                 sigaction(SIGWINCH, NULL, &cwsa);
 195                 if (cwsa.sa_handler == owsa.sa_handler) {
 196                         sigaction(SIGWINCH, &owsa, NULL);
 197                         winch_set = 0;
 198                 } else {
 199                         /*
 200                          * We're now using the programs WINCH handler,
 201                          * so don't restore the previous one.
 202                          */
 203                         winch_set = -1;
 204 #ifdef DEBUG
 205                         __CTRACE(__CTRACE_MISC, "cwsa.sa_handler = %p\n",
 206                             cwsa.sa_handler);
 207 #endif
 208                 }
 209         }
 210 }
 211
 212 /* To allow both SIGTSTP and endwin() to come back nicely, we provide
 213    the following routines. */
 214
 215 int
 216 __stopwin(void)
 217 {
 218 #ifdef DEBUG
 219         __CTRACE(__CTRACE_MISC, "__stopwin\n");
 220 #endif
 221         if (_cursesi_screen->endwin)
 222                 return OK;
 223
 224         /* Get the current terminal state (which the user may have changed). */
 225         (void) tcgetattr(fileno(_cursesi_screen->infd),
 226                          &_cursesi_screen->save_termios);
 227
 228         __restore_stophandler();
 229         __restore_winchhandler();
 230
 231         if (curscr != NULL) {
 232                 __unsetattr(0);
 233                 __mvcur((int) curscr->cury, (int) curscr->curx,
 234                     (int) curscr->maxy - 1, 0, 0);
 235         }
 236
 237         if (meta_off != NULL)
 238                 (void) tputs(meta_off, 0, __cputchar);
 239
 240         if ((curscr != NULL) && (curscr->flags & __KEYPAD))
 241                 (void) tputs(keypad_local, 0, __cputchar);
 242         (void) tputs(cursor_normal, 0, __cputchar);
 243         (void) tputs(exit_ca_mode, 0, __cputchar);
 244         (void) fflush(_cursesi_screen->outfd);
 245         (void) setvbuf(_cursesi_screen->outfd, NULL, _IOLBF, (size_t) 0);
 246
 247         _cursesi_screen->endwin = 1;
 248
 249         return tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSADRAIN,
 250             &_cursesi_screen->orig_termios) ? ERR : OK;
 251 }
 252
 253
 254 void
 255 __restartwin(void)
 256 {
 257         struct winsize win;
 258         int nlines, ncols;
 259
 260 #ifdef DEBUG
 261         __CTRACE(__CTRACE_MISC, "__restartwin\n");
 262 #endif
 263         if (!_cursesi_screen->endwin)
 264                 return;
 265
 266         /* Reset the curses SIGTSTP and SIGWINCH signal handlers. */
 267         __set_stophandler();
 268         __set_winchhandler();
 269
 270         /*
 271          * Check to see if the window size has changed.
 272          * If the application didn't update LINES and COLS,
 273          * set the * resized flag to tell getch() to push KEY_RESIZE.
 274          * Update curscr (which also updates __virtscr) and stdscr
 275          * to match the new size.
 276          */
 277         if (ioctl(fileno(_cursesi_screen->outfd), TIOCGWINSZ, &win) != -1 &&
 278             win.ws_row != 0 && win.ws_col != 0) {
 279                 if (win.ws_row != LINES) {
 280                         LINES = win.ws_row;
 281                         _cursesi_screen->resized = 1;
 282                 }
 283                 if (win.ws_col != COLS) {
 284                         COLS = win.ws_col;
 285                         _cursesi_screen->resized = 1;
 286                 }
 287         }
 288         /*
 289          * We need to make local copies of LINES and COLS, otherwise we
 290          * could lose if they are changed between wresize() calls.
 291          */
 292         nlines = LINES;
 293         ncols = COLS;
 294         if (curscr->maxy != nlines || curscr->maxx != ncols)
 295                 wresize(curscr, nlines, ncols);
 296         if (stdscr->maxy != nlines || stdscr->maxx != ncols)
 297                 wresize(stdscr, nlines, ncols);
 298
 299         /* save the new "default" terminal state */
 300         (void) tcgetattr(fileno(_cursesi_screen->infd),
 301                          &_cursesi_screen->orig_termios);
 302
 303         /* Reset the terminal state to the mode just before we stopped. */
 304         (void) tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSADRAIN,
 305             &_cursesi_screen->save_termios);
 306
 307         /* Restore colours */
 308         __restore_colors();
 309
 310         /* Reset meta */
 311         __restore_meta_state();
 312
 313         /* Restart the screen. */
 314         __startwin(_cursesi_screen);
 315
 316         /* Reset cursor visibility */
 317         __restore_cursor_vis();
 318
 319         /* Repaint the screen. */
 320         wrefresh(curscr);
 321 }
 322
 323 int
 324 def_prog_mode(void)
 325 {
 326         if (_cursesi_screen->endwin)
 327                 return ERR;
 328
 329         return tcgetattr(fileno(_cursesi_screen->infd),
 330             &_cursesi_screen->save_termios) ? ERR : OK;
 331 }
 332
 333 int
 334 reset_prog_mode(void)
 335 {
 336
 337         return tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | 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 }