progs/reset_cmd.c

   1 /****************************************************************************
   2  * Copyright (c) 2016-2017,2019 Free Software Foundation, Inc.              *
   3  *                                                                          *
   4  * Permission is hereby granted, free of charge, to any person obtaining a  *
   5  * copy of this software and associated documentation files (the            *
   6  * "Software"), to deal in the Software without restriction, including      *
   7  * without limitation the rights to use, copy, modify, merge, publish,      *
   8  * distribute, distribute with modifications, sublicense, and/or sell       *
   9  * copies of the Software, and to permit persons to whom the Software is    *
  10  * furnished to do so, subject to the following conditions:                 *
  11  *                                                                          *
  12  * The above copyright notice and this permission notice shall be included  *
  13  * in all copies or substantial portions of the Software.                   *
  14  *                                                                          *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
  16  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
  17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
  18  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
  19  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
  20  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
  21  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
  22  *                                                                          *
  23  * Except as contained in this notice, the name(s) of the above copyright   *
  24  * holders shall not be used in advertising or otherwise to promote the     *
  25  * sale, use or other dealings in this Software without prior written       *
  26  * authorization.                                                           *
  27  ****************************************************************************/
  28
  29 /****************************************************************************
  30  *  Author: Thomas E. Dickey                                                *
  31  ****************************************************************************/
  32
  33 #include <reset_cmd.h>
  34 #include <tty_settings.h>
  35
  36 #include <errno.h>
  37 #include <stdio.h>
  38 #include <fcntl.h>
  39
  40 #if HAVE_SIZECHANGE
  41 # if !defined(sun) || !TERMIOS
  42 #  if HAVE_SYS_IOCTL_H
  43 #   include <sys/ioctl.h>
  44 #  endif
  45 # endif
  46 #endif
  47
  48 #if NEED_PTEM_H
  49 /* they neglected to define struct winsize in termios.h -- it's only
  50    in termio.h  */
  51 #include <sys/stream.h>
  52 #include <sys/ptem.h>
  53 #endif
  54
  55 MODULE_ID("$Id: reset_cmd.c,v 1.17 2019/05/25 22:36:53 tom Exp $")
  56
  57 /*
  58  * SCO defines TIOCGSIZE and the corresponding struct.  Other systems (SunOS,
  59  * Solaris, IRIX) define TIOCGWINSZ and struct winsize.
  60  */
  61 #ifdef TIOCGSIZE
  62 # define IOCTL_GET_WINSIZE TIOCGSIZE
  63 # define IOCTL_SET_WINSIZE TIOCSSIZE
  64 # define STRUCT_WINSIZE struct ttysize
  65 # define WINSIZE_ROWS(n) n.ts_lines
  66 # define WINSIZE_COLS(n) n.ts_cols
  67 #else
  68 # ifdef TIOCGWINSZ
  69 #  define IOCTL_GET_WINSIZE TIOCGWINSZ
  70 #  define IOCTL_SET_WINSIZE TIOCSWINSZ
  71 #  define STRUCT_WINSIZE struct winsize
  72 #  define WINSIZE_ROWS(n) n.ws_row
  73 #  define WINSIZE_COLS(n) n.ws_col
  74 # endif
  75 #endif
  76
  77 static FILE *my_file;
  78
  79 static bool use_reset = FALSE;  /* invoked as reset */
  80 static bool use_init = FALSE;   /* invoked as init */
  81
  82 static void
  83 failed(const char *msg)
  84 {
  85     int code = errno;
  86
  87     (void) fprintf(stderr, "%s: %s: %s\n", _nc_progname, msg, strerror(code));
  88     restore_tty_settings();
  89     (void) fprintf(my_file, "\n");
  90     fflush(my_file);
  91     ExitProgram(ErrSystem(code));
  92     /* NOTREACHED */
  93 }
  94
  95 static bool
  96 cat_file(char *file)
  97 {
  98     FILE *fp;
  99     size_t nr;
 100     char buf[BUFSIZ];
 101     bool sent = FALSE;
 102
 103     if (file != 0) {
 104         if ((fp = fopen(file, "r")) == 0)
 105             failed(file);
 106
 107         while ((nr = fread(buf, sizeof(char), sizeof(buf), fp)) != 0) {
 108             if (fwrite(buf, sizeof(char), nr, my_file) != nr) {
 109                 failed(file);
 110             }
 111             sent = TRUE;
 112         }
 113         fclose(fp);
 114     }
 115     return sent;
 116 }
 117
 118 static int
 119 out_char(int c)
 120 {
 121     return putc(c, my_file);
 122 }
 123
 124 /**************************************************************************
 125  * Mode-setting logic
 126  **************************************************************************/
 127
 128 /* some BSD systems have these built in, some systems are missing
 129  * one or more definitions. The safest solution is to override unless the
 130  * commonly-altered ones are defined.
 131  */
 132 #if !(defined(CERASE) && defined(CINTR) && defined(CKILL) && defined(CQUIT))
 133 #undef CEOF
 134 #undef CERASE
 135 #undef CINTR
 136 #undef CKILL
 137 #undef CLNEXT
 138 #undef CRPRNT
 139 #undef CQUIT
 140 #undef CSTART
 141 #undef CSTOP
 142 #undef CSUSP
 143 #endif
 144
 145 /* control-character defaults */
 146 #ifndef CEOF
 147 #define CEOF    CTRL('D')
 148 #endif
 149 #ifndef CERASE
 150 #define CERASE  CTRL('H')
 151 #endif
 152 #ifndef CINTR
 153 #define CINTR   127             /* ^? */
 154 #endif
 155 #ifndef CKILL
 156 #define CKILL   CTRL('U')
 157 #endif
 158 #ifndef CLNEXT
 159 #define CLNEXT  CTRL('v')
 160 #endif
 161 #ifndef CRPRNT
 162 #define CRPRNT  CTRL('r')
 163 #endif
 164 #ifndef CQUIT
 165 #define CQUIT   CTRL('\\')
 166 #endif
 167 #ifndef CSTART
 168 #define CSTART  CTRL('Q')
 169 #endif
 170 #ifndef CSTOP
 171 #define CSTOP   CTRL('S')
 172 #endif
 173 #ifndef CSUSP
 174 #define CSUSP   CTRL('Z')
 175 #endif
 176
 177 #if defined(_POSIX_VDISABLE)
 178 #define DISABLED(val)   (((_POSIX_VDISABLE != -1) \
 179                        && ((val) == _POSIX_VDISABLE)) \
 180                       || ((val) <= 0))
 181 #else
 182 #define DISABLED(val)   ((int)(val) <= 0)
 183 #endif
 184
 185 #define CHK(val, dft)   (unsigned char) (DISABLED(val) ? dft : val)
 186
 187 #define reset_char(item, value) \
 188     tty_settings->c_cc[item] = CHK(tty_settings->c_cc[item], value)
 189
 190 /*
 191  * Reset the terminal mode bits to a sensible state.  Very useful after
 192  * a child program dies in raw mode.
 193  */
 194 void
 195 reset_tty_settings(int fd, TTY * tty_settings)
 196 {
 197     GET_TTY(fd, tty_settings);
 198
 199 #ifdef TERMIOS
 200 #if defined(VDISCARD) && defined(CDISCARD)
 201     reset_char(VDISCARD, CDISCARD);
 202 #endif
 203     reset_char(VEOF, CEOF);
 204     reset_char(VERASE, CERASE);
 205 #if defined(VFLUSH) && defined(CFLUSH)
 206     reset_char(VFLUSH, CFLUSH);
 207 #endif
 208     reset_char(VINTR, CINTR);
 209     reset_char(VKILL, CKILL);
 210 #if defined(VLNEXT) && defined(CLNEXT)
 211     reset_char(VLNEXT, CLNEXT);
 212 #endif
 213     reset_char(VQUIT, CQUIT);
 214 #if defined(VREPRINT) && defined(CRPRNT)
 215     reset_char(VREPRINT, CRPRNT);
 216 #endif
 217 #if defined(VSTART) && defined(CSTART)
 218     reset_char(VSTART, CSTART);
 219 #endif
 220 #if defined(VSTOP) && defined(CSTOP)
 221     reset_char(VSTOP, CSTOP);
 222 #endif
 223 #if defined(VSUSP) && defined(CSUSP)
 224     reset_char(VSUSP, CSUSP);
 225 #endif
 226 #if defined(VWERASE) && defined(CWERASE)
 227     reset_char(VWERASE, CWERASE);
 228 #endif
 229
 230     tty_settings->c_iflag &= ~((unsigned) (IGNBRK
 231                                            | PARMRK
 232                                            | INPCK
 233                                            | ISTRIP
 234                                            | INLCR
 235                                            | IGNCR
 236 #ifdef IUCLC
 237                                            | IUCLC
 238 #endif
 239 #ifdef IXANY
 240                                            | IXANY
 241 #endif
 242                                            | IXOFF));
 243
 244     tty_settings->c_iflag |= (BRKINT
 245                               | IGNPAR
 246                               | ICRNL
 247                               | IXON
 248 #ifdef IMAXBEL
 249                               | IMAXBEL
 250 #endif
 251         );
 252
 253     tty_settings->c_oflag &= ~((unsigned) (0
 254 #ifdef OLCUC
 255                                            | OLCUC
 256 #endif
 257 #ifdef OCRNL
 258                                            | OCRNL
 259 #endif
 260 #ifdef ONOCR
 261                                            | ONOCR
 262 #endif
 263 #ifdef ONLRET
 264                                            | ONLRET
 265 #endif
 266 #ifdef OFILL
 267                                            | OFILL
 268 #endif
 269 #ifdef OFDEL
 270                                            | OFDEL
 271 #endif
 272 #ifdef NLDLY
 273                                            | NLDLY
 274 #endif
 275 #ifdef CRDLY
 276                                            | CRDLY
 277 #endif
 278 #ifdef TABDLY
 279                                            | TABDLY
 280 #endif
 281 #ifdef BSDLY
 282                                            | BSDLY
 283 #endif
 284 #ifdef VTDLY
 285                                            | VTDLY
 286 #endif
 287 #ifdef FFDLY
 288                                            | FFDLY
 289 #endif
 290                                ));
 291
 292     tty_settings->c_oflag |= (OPOST
 293 #ifdef ONLCR
 294                               | ONLCR
 295 #endif
 296         );
 297
 298     tty_settings->c_cflag &= ~((unsigned) (CSIZE
 299                                            | CSTOPB
 300                                            | PARENB
 301                                            | PARODD
 302                                            | CLOCAL));
 303     tty_settings->c_cflag |= (CS8 | CREAD);
 304     tty_settings->c_lflag &= ~((unsigned) (ECHONL
 305                                            | NOFLSH
 306 #ifdef TOSTOP
 307                                            | TOSTOP
 308 #endif
 309 #ifdef ECHOPTR
 310                                            | ECHOPRT
 311 #endif
 312 #ifdef XCASE
 313                                            | XCASE
 314 #endif
 315                                ));
 316
 317     tty_settings->c_lflag |= (ISIG
 318                               | ICANON
 319                               | ECHO
 320                               | ECHOE
 321                               | ECHOK
 322 #ifdef ECHOCTL
 323                               | ECHOCTL
 324 #endif
 325 #ifdef ECHOKE
 326                               | ECHOKE
 327 #endif
 328         );
 329 #endif
 330
 331     SET_TTY(fd, tty_settings);
 332 }
 333
 334 /*
 335  * Returns a "good" value for the erase character.  This is loosely based on
 336  * the BSD4.4 logic.
 337  */
 338 static int
 339 default_erase(void)
 340 {
 341     int result;
 342
 343     if (over_strike
 344         && VALID_STRING(key_backspace)
 345         && strlen(key_backspace) == 1) {
 346         result = key_backspace[0];
 347     } else {
 348         result = CERASE;
 349     }
 350
 351     return result;
 352 }
 353
 354 /*
 355  * Update the values of the erase, interrupt, and kill characters in the TTY
 356  * parameter.
 357  *
 358  * SVr4 tset (e.g., Solaris 2.5) only modifies the intr, quit or erase
 359  * characters if they're unset, or if we specify them as options.  This differs
 360  * from BSD 4.4 tset, which always sets erase.
 361  */
 362 void
 363 set_control_chars(TTY * tty_settings, int my_erase, int my_intr, int my_kill)
 364 {
 365     if (DISABLED(tty_settings->c_cc[VERASE]) || my_erase >= 0) {
 366         tty_settings->c_cc[VERASE] = UChar((my_erase >= 0)
 367                                            ? my_erase
 368                                            : default_erase());
 369     }
 370
 371     if (DISABLED(tty_settings->c_cc[VINTR]) || my_intr >= 0) {
 372         tty_settings->c_cc[VINTR] = UChar((my_intr >= 0)
 373                                           ? my_intr
 374                                           : CINTR);
 375     }
 376
 377     if (DISABLED(tty_settings->c_cc[VKILL]) || my_kill >= 0) {
 378         tty_settings->c_cc[VKILL] = UChar((my_kill >= 0)
 379                                           ? my_kill
 380                                           : CKILL);
 381     }
 382 }
 383
 384 /*
 385  * Set up various conversions in the TTY parameter, including parity, tabs,
 386  * returns, echo, and case, according to the termcap entry.
 387  */
 388 void
 389 set_conversions(TTY * tty_settings)
 390 {
 391 #ifdef ONLCR
 392     tty_settings->c_oflag |= ONLCR;
 393 #endif
 394     tty_settings->c_iflag |= ICRNL;
 395     tty_settings->c_lflag |= ECHO;
 396 #ifdef OXTABS
 397     tty_settings->c_oflag |= OXTABS;
 398 #endif /* OXTABS */
 399
 400     /* test used to be tgetflag("NL") */
 401     if (VALID_STRING(newline) && newline[0] == '\n' && !newline[1]) {
 402         /* Newline, not linefeed. */
 403 #ifdef ONLCR
 404         tty_settings->c_oflag &= ~((unsigned) ONLCR);
 405 #endif
 406         tty_settings->c_iflag &= ~((unsigned) ICRNL);
 407     }
 408 #ifdef OXTABS
 409     /* test used to be tgetflag("pt") */
 410     if (VALID_STRING(set_tab) && VALID_STRING(clear_all_tabs))
 411         tty_settings->c_oflag &= ~OXTABS;
 412 #endif /* OXTABS */
 413     tty_settings->c_lflag |= (ECHOE | ECHOK);
 414 }
 415
 416 static bool
 417 sent_string(const char *s)
 418 {
 419     bool sent = FALSE;
 420     if (VALID_STRING(s)) {
 421         tputs(s, 0, out_char);
 422         sent = TRUE;
 423     }
 424     return sent;
 425 }
 426
 427 static bool
 428 to_left_margin(void)
 429 {
 430     if (VALID_STRING(carriage_return)) {
 431         sent_string(carriage_return);
 432     } else {
 433         out_char('\r');
 434     }
 435     return TRUE;
 436 }
 437
 438 /*
 439  * Set the hardware tabs on the terminal, using the 'ct' (clear all tabs),
 440  * 'st' (set one tab) and 'ch' (horizontal cursor addressing) capabilities.
 441  * This is done before 'if' and 'is', so they can recover in case of error.
 442  *
 443  * Return TRUE if we set any tab stops, FALSE if not.
 444  */
 445 static bool
 446 reset_tabstops(int wide)
 447 {
 448     if ((init_tabs != 8)
 449         && VALID_NUMERIC(init_tabs)
 450         && VALID_STRING(set_tab)
 451         && VALID_STRING(clear_all_tabs)) {
 452         int c;
 453
 454         to_left_margin();
 455         tputs(clear_all_tabs, 0, out_char);
 456         if (init_tabs > 1) {
 457             if (init_tabs > wide)
 458                 init_tabs = (short) wide;
 459             for (c = init_tabs; c < wide; c += init_tabs) {
 460                 fprintf(my_file, "%*s", init_tabs, " ");
 461                 tputs(set_tab, 0, out_char);
 462             }
 463             to_left_margin();
 464         }
 465         return (TRUE);
 466     }
 467     return (FALSE);
 468 }
 469
 470 /* Output startup string. */
 471 bool
 472 send_init_strings(int fd GCC_UNUSED, TTY * old_settings)
 473 {
 474     int i;
 475     bool need_flush = FALSE;
 476
 477     (void) old_settings;
 478 #ifdef TAB3
 479     if (old_settings != 0 &&
 480         old_settings->c_oflag & (TAB3 | ONLCR | OCRNL | ONLRET)) {
 481         old_settings->c_oflag &= (TAB3 | ONLCR | OCRNL | ONLRET);
 482         SET_TTY(fd, old_settings);
 483     }
 484 #endif
 485     if (use_reset || use_init) {
 486         if (VALID_STRING(init_prog)) {
 487             IGNORE_RC(system(init_prog));
 488         }
 489
 490         need_flush |= sent_string((use_reset && (reset_1string != 0))
 491                                   ? reset_1string
 492                                   : init_1string);
 493
 494         need_flush |= sent_string((use_reset && (reset_2string != 0))
 495                                   ? reset_2string
 496                                   : init_2string);
 497
 498 #if defined(set_lr_margin)
 499         if (VALID_STRING(set_lr_margin)) {
 500             need_flush |= sent_string(TPARM_2(set_lr_margin, 0,
 501                                               columns - 1));
 502         } else
 503 #endif
 504 #if defined(set_left_margin_parm) && defined(set_right_margin_parm)
 505             if (VALID_STRING(set_left_margin_parm)
 506                 && VALID_STRING(set_right_margin_parm)) {
 507             need_flush |= sent_string(TPARM_1(set_left_margin_parm, 0));
 508             need_flush |= sent_string(TPARM_1(set_right_margin_parm,
 509                                               columns - 1));
 510         } else
 511 #endif
 512             if (VALID_STRING(clear_margins)
 513                 && VALID_STRING(set_left_margin)
 514                 && VALID_STRING(set_right_margin)) {
 515             need_flush |= sent_string(clear_margins);
 516             need_flush |= to_left_margin();
 517             need_flush |= sent_string(set_left_margin);
 518             if (VALID_STRING(parm_right_cursor)) {
 519                 need_flush |= sent_string(TPARM_1(parm_right_cursor,
 520                                                   columns - 1));
 521             } else {
 522                 for (i = 0; i < columns - 1; i++) {
 523                     out_char(' ');
 524                     need_flush = TRUE;
 525                 }
 526             }
 527             need_flush |= sent_string(set_right_margin);
 528             need_flush |= to_left_margin();
 529         }
 530
 531         need_flush |= reset_tabstops(columns);
 532
 533         need_flush |= cat_file((use_reset && reset_file) ? reset_file : init_file);
 534
 535         need_flush |= sent_string((use_reset && (reset_3string != 0))
 536                                   ? reset_3string
 537                                   : init_3string);
 538     }
 539
 540     return need_flush;
 541 }
 542
 543 /*
 544  * Tell the user if a control key has been changed from the default value.
 545  */
 546 static void
 547 show_tty_change(TTY * old_settings,
 548                 TTY * new_settings,
 549                 const char *name,
 550                 int which,
 551                 unsigned def)
 552 {
 553     unsigned older, newer;
 554     char *p;
 555
 556     newer = new_settings->c_cc[which];
 557     older = old_settings->c_cc[which];
 558
 559     if (older == newer && older == def)
 560         return;
 561
 562     (void) fprintf(stderr, "%s %s ", name, older == newer ? "is" : "set to");
 563
 564     if (DISABLED(newer)) {
 565         (void) fprintf(stderr, "undef.\n");
 566         /*
 567          * Check 'delete' before 'backspace', since the key_backspace value
 568          * is ambiguous.
 569          */
 570     } else if (newer == 0177) {
 571         (void) fprintf(stderr, "delete.\n");
 572     } else if ((p = key_backspace) != 0
 573                && newer == (unsigned char) p[0]
 574                && p[1] == '\0') {
 575         (void) fprintf(stderr, "backspace.\n");
 576     } else if (newer < 040) {
 577         newer ^= 0100;
 578         (void) fprintf(stderr, "control-%c (^%c).\n", UChar(newer), UChar(newer));
 579     } else
 580         (void) fprintf(stderr, "%c.\n", UChar(newer));
 581 }
 582
 583 /**************************************************************************
 584  * Miscellaneous.
 585  **************************************************************************/
 586
 587 void
 588 reset_start(FILE *fp, bool is_reset, bool is_init)
 589 {
 590     my_file = fp;
 591     use_reset = is_reset;
 592     use_init = is_init;
 593 }
 594
 595 void
 596 reset_flush(void)
 597 {
 598     if (my_file != 0)
 599         fflush(my_file);
 600 }
 601
 602 void
 603 print_tty_chars(TTY * old_settings, TTY * new_settings)
 604 {
 605     show_tty_change(old_settings, new_settings, "Erase", VERASE, CERASE);
 606     show_tty_change(old_settings, new_settings, "Kill", VKILL, CKILL);
 607     show_tty_change(old_settings, new_settings, "Interrupt", VINTR, CINTR);
 608 }
 609
 610 #if HAVE_SIZECHANGE
 611 /*
 612  * Set window size if not set already, but update our copy of the values if the
 613  * size was set.
 614  */
 615 void
 616 set_window_size(int fd, short *high, short *wide)
 617 {
 618     STRUCT_WINSIZE win;
 619     (void) ioctl(fd, IOCTL_GET_WINSIZE, &win);
 620     if (WINSIZE_ROWS(win) == 0 &&
 621         WINSIZE_COLS(win) == 0) {
 622         if (*high > 0 && *wide > 0) {
 623             WINSIZE_ROWS(win) = (unsigned short) *high;
 624             WINSIZE_COLS(win) = (unsigned short) *wide;
 625             (void) ioctl(fd, IOCTL_SET_WINSIZE, &win);
 626         }
 627     } else if (WINSIZE_ROWS(win) > 0 &&
 628                WINSIZE_COLS(win) > 0) {
 629         *high = (short) WINSIZE_ROWS(win);
 630         *wide = (short) WINSIZE_COLS(win);
 631     }
 632 }
 633 #endif