progs/reset_cmd.c

   1 /****************************************************************************
   2  * Copyright 2019,2020 Thomas E. Dickey                                     *
   3  * Copyright 2016,2017 Free Software Foundation, Inc.                       *
   4  *                                                                          *
   5  * Permission is hereby granted, free of charge, to any person obtaining a  *
   6  * copy of this software and associated documentation files (the            *
   7  * "Software"), to deal in the Software without restriction, including      *
   8  * without limitation the rights to use, copy, modify, merge, publish,      *
   9  * distribute, distribute with modifications, sublicense, and/or sell       *
  10  * copies of the Software, and to permit persons to whom the Software is    *
  11  * furnished to do so, subject to the following conditions:                 *
  12  *                                                                          *
  13  * The above copyright notice and this permission notice shall be included  *
  14  * in all copies or substantial portions of the Software.                   *
  15  *                                                                          *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
  18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
  19  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
  20  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
  21  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
  22  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
  23  *                                                                          *
  24  * Except as contained in this notice, the name(s) of the above copyright   *
  25  * holders shall not be used in advertising or otherwise to promote the     *
  26  * sale, use or other dealings in this Software without prior written       *
  27  * authorization.                                                           *
  28  ****************************************************************************/
  29
  30 /****************************************************************************
  31  *  Author: Thomas E. Dickey                                                *
  32  ****************************************************************************/
  33
  34 #include <reset_cmd.h>
  35 #include <tty_settings.h>
  36
  37 #include <errno.h>
  38 #include <stdio.h>
  39 #include <fcntl.h>
  40
  41 #if HAVE_SIZECHANGE
  42 # if !defined(sun) || !TERMIOS
  43 #  if HAVE_SYS_IOCTL_H
  44 #   include <sys/ioctl.h>
  45 #  endif
  46 # endif
  47 #endif
  48
  49 #if NEED_PTEM_H
  50 /* they neglected to define struct winsize in termios.h -- it's only
  51    in termio.h  */
  52 #include <sys/stream.h>
  53 #include <sys/ptem.h>
  54 #endif
  55
  56 MODULE_ID("$Id: reset_cmd.c,v 1.23 2020/09/05 22:54:47 tom Exp $")
  57
  58 /*
  59  * SCO defines TIOCGSIZE and the corresponding struct.  Other systems (SunOS,
  60  * Solaris, IRIX) define TIOCGWINSZ and struct winsize.
  61  */
  62 #ifdef TIOCGSIZE
  63 # define IOCTL_GET_WINSIZE TIOCGSIZE
  64 # define IOCTL_SET_WINSIZE TIOCSSIZE
  65 # define STRUCT_WINSIZE struct ttysize
  66 # define WINSIZE_ROWS(n) n.ts_lines
  67 # define WINSIZE_COLS(n) n.ts_cols
  68 #else
  69 # ifdef TIOCGWINSZ
  70 #  define IOCTL_GET_WINSIZE TIOCGWINSZ
  71 #  define IOCTL_SET_WINSIZE TIOCSWINSZ
  72 #  define STRUCT_WINSIZE struct winsize
  73 #  define WINSIZE_ROWS(n) n.ws_row
  74 #  define WINSIZE_COLS(n) n.ws_col
  75 # endif
  76 #endif
  77
  78 static FILE *my_file;
  79
  80 static bool use_reset = FALSE;  /* invoked as reset */
  81 static bool use_init = FALSE;   /* invoked as init */
  82
  83 static void
  84 failed(const char *msg)
  85 {
  86     int code = errno;
  87
  88     (void) fprintf(stderr, "%s: %s: %s\n", _nc_progname, msg, strerror(code));
  89     restore_tty_settings();
  90     (void) fprintf(my_file, "\n");
  91     fflush(my_file);
  92     ExitProgram(ErrSystem(code));
  93     /* NOTREACHED */
  94 }
  95
  96 static bool
  97 cat_file(char *file)
  98 {
  99     FILE *fp;
 100     size_t nr;
 101     char buf[BUFSIZ];
 102     bool sent = FALSE;
 103
 104     if (file != 0) {
 105         if ((fp = fopen(file, "r")) == 0)
 106             failed(file);
 107
 108         while ((nr = fread(buf, sizeof(char), sizeof(buf), fp)) != 0) {
 109             if (fwrite(buf, sizeof(char), nr, my_file) != nr) {
 110                 failed(file);
 111             }
 112             sent = TRUE;
 113         }
 114         fclose(fp);
 115     }
 116     return sent;
 117 }
 118
 119 static int
 120 out_char(int c)
 121 {
 122     return putc(c, my_file);
 123 }
 124
 125 /**************************************************************************
 126  * Mode-setting logic
 127  **************************************************************************/
 128
 129 /* some BSD systems have these built in, some systems are missing
 130  * one or more definitions. The safest solution is to override unless the
 131  * commonly-altered ones are defined.
 132  */
 133 #if !(defined(CERASE) && defined(CINTR) && defined(CKILL) && defined(CQUIT))
 134 #undef CEOF
 135 #undef CERASE
 136 #undef CINTR
 137 #undef CKILL
 138 #undef CLNEXT
 139 #undef CRPRNT
 140 #undef CQUIT
 141 #undef CSTART
 142 #undef CSTOP
 143 #undef CSUSP
 144 #endif
 145
 146 /* control-character defaults */
 147 #ifndef CEOF
 148 #define CEOF    CTRL('D')
 149 #endif
 150 #ifndef CERASE
 151 #define CERASE  CTRL('H')
 152 #endif
 153 #ifndef CINTR
 154 #define CINTR   127             /* ^? */
 155 #endif
 156 #ifndef CKILL
 157 #define CKILL   CTRL('U')
 158 #endif
 159 #ifndef CLNEXT
 160 #define CLNEXT  CTRL('v')
 161 #endif
 162 #ifndef CRPRNT
 163 #define CRPRNT  CTRL('r')
 164 #endif
 165 #ifndef CQUIT
 166 #define CQUIT   CTRL('\\')
 167 #endif
 168 #ifndef CSTART
 169 #define CSTART  CTRL('Q')
 170 #endif
 171 #ifndef CSTOP
 172 #define CSTOP   CTRL('S')
 173 #endif
 174 #ifndef CSUSP
 175 #define CSUSP   CTRL('Z')
 176 #endif
 177
 178 #if defined(_POSIX_VDISABLE)
 179 #define DISABLED(val)   (((_POSIX_VDISABLE != -1) \
 180                        && ((val) == _POSIX_VDISABLE)) \
 181                       || ((val) <= 0))
 182 #else
 183 #define DISABLED(val)   ((int)(val) <= 0)
 184 #endif
 185
 186 #define CHK(val, dft)   (unsigned char) (DISABLED(val) ? dft : val)
 187
 188 #define reset_char(item, value) \
 189     tty_settings->c_cc[item] = CHK(tty_settings->c_cc[item], value)
 190
 191 /*
 192  * Reset the terminal mode bits to a sensible state.  Very useful after
 193  * a child program dies in raw mode.
 194  */
 195 void
 196 reset_tty_settings(int fd, TTY * tty_settings)
 197 {
 198     GET_TTY(fd, tty_settings);
 199
 200 #ifdef TERMIOS
 201 #if defined(VDISCARD) && defined(CDISCARD)
 202     reset_char(VDISCARD, CDISCARD);
 203 #endif
 204     reset_char(VEOF, CEOF);
 205     reset_char(VERASE, CERASE);
 206 #if defined(VFLUSH) && defined(CFLUSH)
 207     reset_char(VFLUSH, CFLUSH);
 208 #endif
 209     reset_char(VINTR, CINTR);
 210     reset_char(VKILL, CKILL);
 211 #if defined(VLNEXT) && defined(CLNEXT)
 212     reset_char(VLNEXT, CLNEXT);
 213 #endif
 214     reset_char(VQUIT, CQUIT);
 215 #if defined(VREPRINT) && defined(CRPRNT)
 216     reset_char(VREPRINT, CRPRNT);
 217 #endif
 218 #if defined(VSTART) && defined(CSTART)
 219     reset_char(VSTART, CSTART);
 220 #endif
 221 #if defined(VSTOP) && defined(CSTOP)
 222     reset_char(VSTOP, CSTOP);
 223 #endif
 224 #if defined(VSUSP) && defined(CSUSP)
 225     reset_char(VSUSP, CSUSP);
 226 #endif
 227 #if defined(VWERASE) && defined(CWERASE)
 228     reset_char(VWERASE, CWERASE);
 229 #endif
 230
 231     tty_settings->c_iflag &= ~((unsigned) (IGNBRK
 232                                            | PARMRK
 233                                            | INPCK
 234                                            | ISTRIP
 235                                            | INLCR
 236                                            | IGNCR
 237 #ifdef IUCLC
 238                                            | IUCLC
 239 #endif
 240 #ifdef IXANY
 241                                            | IXANY
 242 #endif
 243                                            | IXOFF));
 244
 245     tty_settings->c_iflag |= (BRKINT
 246                               | IGNPAR
 247                               | ICRNL
 248                               | IXON
 249 #ifdef IMAXBEL
 250                               | IMAXBEL
 251 #endif
 252         );
 253
 254     tty_settings->c_oflag &= ~((unsigned) (0
 255 #ifdef OLCUC
 256                                            | OLCUC
 257 #endif
 258 #ifdef OCRNL
 259                                            | OCRNL
 260 #endif
 261 #ifdef ONOCR
 262                                            | ONOCR
 263 #endif
 264 #ifdef ONLRET
 265                                            | ONLRET
 266 #endif
 267 #ifdef OFILL
 268                                            | OFILL
 269 #endif
 270 #ifdef OFDEL
 271                                            | OFDEL
 272 #endif
 273 #ifdef NLDLY
 274                                            | NLDLY
 275 #endif
 276 #ifdef CRDLY
 277                                            | CRDLY
 278 #endif
 279 #ifdef TABDLY
 280                                            | TABDLY
 281 #endif
 282 #ifdef BSDLY
 283                                            | BSDLY
 284 #endif
 285 #ifdef VTDLY
 286                                            | VTDLY
 287 #endif
 288 #ifdef FFDLY
 289                                            | FFDLY
 290 #endif
 291                                ));
 292
 293     tty_settings->c_oflag |= (OPOST
 294 #ifdef ONLCR
 295                               | ONLCR
 296 #endif
 297         );
 298
 299     tty_settings->c_cflag &= ~((unsigned) (CSIZE
 300                                            | CSTOPB
 301                                            | PARENB
 302                                            | PARODD
 303                                            | CLOCAL));
 304     tty_settings->c_cflag |= (CS8 | CREAD);
 305     tty_settings->c_lflag &= ~((unsigned) (ECHONL
 306                                            | NOFLSH
 307 #ifdef TOSTOP
 308                                            | TOSTOP
 309 #endif
 310 #ifdef ECHOPTR
 311                                            | ECHOPRT
 312 #endif
 313 #ifdef XCASE
 314                                            | XCASE
 315 #endif
 316                                ));
 317
 318     tty_settings->c_lflag |= (ISIG
 319                               | ICANON
 320                               | ECHO
 321                               | ECHOE
 322                               | ECHOK
 323 #ifdef ECHOCTL
 324                               | ECHOCTL
 325 #endif
 326 #ifdef ECHOKE
 327                               | ECHOKE
 328 #endif
 329         );
 330 #endif
 331
 332     SET_TTY(fd, tty_settings);
 333 }
 334
 335 /*
 336  * Returns a "good" value for the erase character.  This is loosely based on
 337  * the BSD4.4 logic.
 338  */
 339 static int
 340 default_erase(void)
 341 {
 342     int result;
 343
 344     if (over_strike
 345         && VALID_STRING(key_backspace)
 346         && strlen(key_backspace) == 1) {
 347         result = key_backspace[0];
 348     } else {
 349         result = CERASE;
 350     }
 351
 352     return result;
 353 }
 354
 355 /*
 356  * Update the values of the erase, interrupt, and kill characters in the TTY
 357  * parameter.
 358  *
 359  * SVr4 tset (e.g., Solaris 2.5) only modifies the intr, quit or erase
 360  * characters if they're unset, or if we specify them as options.  This differs
 361  * from BSD 4.4 tset, which always sets erase.
 362  */
 363 void
 364 set_control_chars(TTY * tty_settings, int my_erase, int my_intr, int my_kill)
 365 {
 366 #if defined(EXP_WIN32_DRIVER)
 367     /* noop */
 368 #else
 369     if (DISABLED(tty_settings->c_cc[VERASE]) || my_erase >= 0) {
 370         tty_settings->c_cc[VERASE] = UChar((my_erase >= 0)
 371                                            ? my_erase
 372                                            : default_erase());
 373     }
 374
 375     if (DISABLED(tty_settings->c_cc[VINTR]) || my_intr >= 0) {
 376         tty_settings->c_cc[VINTR] = UChar((my_intr >= 0)
 377                                           ? my_intr
 378                                           : CINTR);
 379     }
 380
 381     if (DISABLED(tty_settings->c_cc[VKILL]) || my_kill >= 0) {
 382         tty_settings->c_cc[VKILL] = UChar((my_kill >= 0)
 383                                           ? my_kill
 384                                           : CKILL);
 385     }
 386 #endif
 387 }
 388
 389 /*
 390  * Set up various conversions in the TTY parameter, including parity, tabs,
 391  * returns, echo, and case, according to the termcap entry.
 392  */
 393 void
 394 set_conversions(TTY * tty_settings)
 395 {
 396 #if defined(EXP_WIN32_DRIVER)
 397     /* FIXME */
 398 #else
 399 #ifdef ONLCR
 400     tty_settings->c_oflag |= ONLCR;
 401 #endif
 402     tty_settings->c_iflag |= ICRNL;
 403     tty_settings->c_lflag |= ECHO;
 404 #ifdef OXTABS
 405     tty_settings->c_oflag |= OXTABS;
 406 #endif /* OXTABS */
 407
 408     /* test used to be tgetflag("NL") */
 409     if (VALID_STRING(newline) && newline[0] == '\n' && !newline[1]) {
 410         /* Newline, not linefeed. */
 411 #ifdef ONLCR
 412         tty_settings->c_oflag &= ~((unsigned) ONLCR);
 413 #endif
 414         tty_settings->c_iflag &= ~((unsigned) ICRNL);
 415     }
 416 #ifdef OXTABS
 417     /* test used to be tgetflag("pt") */
 418     if (VALID_STRING(set_tab) && VALID_STRING(clear_all_tabs))
 419         tty_settings->c_oflag &= ~OXTABS;
 420 #endif /* OXTABS */
 421     tty_settings->c_lflag |= (ECHOE | ECHOK);
 422 #endif
 423 }
 424
 425 static bool
 426 sent_string(const char *s)
 427 {
 428     bool sent = FALSE;
 429     if (VALID_STRING(s)) {
 430         tputs(s, 0, out_char);
 431         sent = TRUE;
 432     }
 433     return sent;
 434 }
 435
 436 static bool
 437 to_left_margin(void)
 438 {
 439     if (VALID_STRING(carriage_return)) {
 440         sent_string(carriage_return);
 441     } else {
 442         out_char('\r');
 443     }
 444     return TRUE;
 445 }
 446
 447 /*
 448  * Set the hardware tabs on the terminal, using the 'ct' (clear all tabs),
 449  * 'st' (set one tab) and 'ch' (horizontal cursor addressing) capabilities.
 450  * This is done before 'if' and 'is', so they can recover in case of error.
 451  *
 452  * Return TRUE if we set any tab stops, FALSE if not.
 453  */
 454 static bool
 455 reset_tabstops(int wide)
 456 {
 457     if ((init_tabs != 8)
 458         && VALID_NUMERIC(init_tabs)
 459         && VALID_STRING(set_tab)
 460         && VALID_STRING(clear_all_tabs)) {
 461         int c;
 462
 463         to_left_margin();
 464         tputs(clear_all_tabs, 0, out_char);
 465         if (init_tabs > 1) {
 466             if (init_tabs > wide)
 467                 init_tabs = (short) wide;
 468             for (c = init_tabs; c < wide; c += init_tabs) {
 469                 fprintf(my_file, "%*s", init_tabs, " ");
 470                 tputs(set_tab, 0, out_char);
 471             }
 472             to_left_margin();
 473         }
 474         return (TRUE);
 475     }
 476     return (FALSE);
 477 }
 478
 479 /* Output startup string. */
 480 bool
 481 send_init_strings(int fd GCC_UNUSED, TTY * old_settings)
 482 {
 483     int i;
 484     bool need_flush = FALSE;
 485
 486     (void) old_settings;
 487 #ifdef TAB3
 488     if (old_settings != 0 &&
 489         old_settings->c_oflag & (TAB3 | ONLCR | OCRNL | ONLRET)) {
 490         old_settings->c_oflag &= (TAB3 | ONLCR | OCRNL | ONLRET);
 491         SET_TTY(fd, old_settings);
 492     }
 493 #endif
 494     if (use_reset || use_init) {
 495         if (VALID_STRING(init_prog)) {
 496             IGNORE_RC(system(init_prog));
 497         }
 498
 499         need_flush |= sent_string((use_reset && (reset_1string != 0))
 500                                   ? reset_1string
 501                                   : init_1string);
 502
 503         need_flush |= sent_string((use_reset && (reset_2string != 0))
 504                                   ? reset_2string
 505                                   : init_2string);
 506
 507         if (VALID_STRING(clear_margins)) {
 508             need_flush |= sent_string(clear_margins);
 509         } else
 510 #if defined(set_lr_margin)
 511         if (VALID_STRING(set_lr_margin)) {
 512             need_flush |= sent_string(TIPARM_2(set_lr_margin, 0, columns - 1));
 513         } else
 514 #endif
 515 #if defined(set_left_margin_parm) && defined(set_right_margin_parm)
 516             if (VALID_STRING(set_left_margin_parm)
 517                 && VALID_STRING(set_right_margin_parm)) {
 518             need_flush |= sent_string(TIPARM_1(set_left_margin_parm, 0));
 519             need_flush |= sent_string(TIPARM_1(set_right_margin_parm,
 520                                                columns - 1));
 521         } else
 522 #endif
 523             if (VALID_STRING(set_left_margin)
 524                 && VALID_STRING(set_right_margin)) {
 525             need_flush |= to_left_margin();
 526             need_flush |= sent_string(set_left_margin);
 527             if (VALID_STRING(parm_right_cursor)) {
 528                 need_flush |= sent_string(TIPARM_1(parm_right_cursor,
 529                                                    columns - 1));
 530             } else {
 531                 for (i = 0; i < columns - 1; i++) {
 532                     out_char(' ');
 533                     need_flush = TRUE;
 534                 }
 535             }
 536             need_flush |= sent_string(set_right_margin);
 537             need_flush |= to_left_margin();
 538         }
 539
 540         need_flush |= reset_tabstops(columns);
 541
 542         need_flush |= cat_file((use_reset && reset_file) ? reset_file : init_file);
 543
 544         need_flush |= sent_string((use_reset && (reset_3string != 0))
 545                                   ? reset_3string
 546                                   : init_3string);
 547     }
 548
 549     return need_flush;
 550 }
 551
 552 /*
 553  * Tell the user if a control key has been changed from the default value.
 554  */
 555 static void
 556 show_tty_change(TTY * old_settings,
 557                 TTY * new_settings,
 558                 const char *name,
 559                 int which,
 560                 unsigned def)
 561 {
 562     unsigned older = 0, newer = 0;
 563     char *p;
 564
 565 #if defined(EXP_WIN32_DRIVER)
 566     /* noop */
 567 #else
 568     newer = new_settings->c_cc[which];
 569     older = old_settings->c_cc[which];
 570
 571     if (older == newer && older == def)
 572         return;
 573 #endif
 574     (void) fprintf(stderr, "%s %s ", name, older == newer ? "is" : "set to");
 575
 576     if (DISABLED(newer)) {
 577         (void) fprintf(stderr, "undef.\n");
 578         /*
 579          * Check 'delete' before 'backspace', since the key_backspace value
 580          * is ambiguous.
 581          */
 582     } else if (newer == 0177) {
 583         (void) fprintf(stderr, "delete.\n");
 584     } else if ((p = key_backspace) != 0
 585                && newer == (unsigned char) p[0]
 586                && p[1] == '\0') {
 587         (void) fprintf(stderr, "backspace.\n");
 588     } else if (newer < 040) {
 589         newer ^= 0100;
 590         (void) fprintf(stderr, "control-%c (^%c).\n", UChar(newer), UChar(newer));
 591     } else
 592         (void) fprintf(stderr, "%c.\n", UChar(newer));
 593 }
 594
 595 /**************************************************************************
 596  * Miscellaneous.
 597  **************************************************************************/
 598
 599 void
 600 reset_start(FILE *fp, bool is_reset, bool is_init)
 601 {
 602     my_file = fp;
 603     use_reset = is_reset;
 604     use_init = is_init;
 605 }
 606
 607 void
 608 reset_flush(void)
 609 {
 610     if (my_file != 0)
 611         fflush(my_file);
 612 }
 613
 614 void
 615 print_tty_chars(TTY * old_settings, TTY * new_settings)
 616 {
 617 #if defined(EXP_WIN32_DRIVER)
 618     /* noop */
 619 #else
 620     show_tty_change(old_settings, new_settings, "Erase", VERASE, CERASE);
 621     show_tty_change(old_settings, new_settings, "Kill", VKILL, CKILL);
 622     show_tty_change(old_settings, new_settings, "Interrupt", VINTR, CINTR);
 623 #endif
 624 }
 625
 626 #if HAVE_SIZECHANGE
 627 /*
 628  * Set window size if not set already, but update our copy of the values if the
 629  * size was set.
 630  */
 631 void
 632 set_window_size(int fd, short *high, short *wide)
 633 {
 634     STRUCT_WINSIZE win;
 635     (void) ioctl(fd, IOCTL_GET_WINSIZE, &win);
 636     if (WINSIZE_ROWS(win) == 0 &&
 637         WINSIZE_COLS(win) == 0) {
 638         if (*high > 0 && *wide > 0) {
 639             WINSIZE_ROWS(win) = (unsigned short) *high;
 640             WINSIZE_COLS(win) = (unsigned short) *wide;
 641             (void) ioctl(fd, IOCTL_SET_WINSIZE, &win);
 642         }
 643     } else if (WINSIZE_ROWS(win) > 0 &&
 644                WINSIZE_COLS(win) > 0) {
 645         *high = (short) WINSIZE_ROWS(win);
 646         *wide = (short) WINSIZE_COLS(win);
 647     }
 648 }
 649 #endif