bin/ed/main.c

   1 /*      $NetBSD: main.c,v 1.21 2009/06/10 03:24:27 ginsbach Exp $       */
   2
   3 /* main.c: This file contains the main control and user-interface routines
   4    for the ed line editor. */
   5 /*-
   6  * Copyright (c) 1993 Andrew Moore, Talke Studio.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  */
  30
  31 #include <sys/cdefs.h>
  32 #ifndef lint
  33 __COPYRIGHT(
  34 "@(#) Copyright (c) 1993 Andrew Moore, Talke Studio.\
  35  All rights reserved.");
  36 #endif /* not lint */
  37
  38 #ifndef lint
  39 #if 0
  40 static char *rcsid = "@(#)main.c,v 1.1 1994/02/01 00:34:42 alm Exp";
  41 #else
  42 __RCSID("$NetBSD: main.c,v 1.21 2009/06/10 03:24:27 ginsbach Exp $");
  43 #endif
  44 #endif /* not lint */
  45
  46 /*
  47  * CREDITS
  48  *
  49  *      This program is based on the editor algorithm described in
  50  *      Brian W. Kernighan and P. J. Plauger's book "Software Tools
  51  *      in Pascal," Addison-Wesley, 1981.
  52  *
  53  *      The buffering algorithm is attributed to Rodney Ruddock of
  54  *      the University of Guelph, Guelph, Ontario.
  55  *
  56  *      The cbc.c encryption code is adapted from
  57  *      the bdes program by Matt Bishop of Dartmouth College,
  58  *      Hanover, NH.
  59  *
  60  */
  61
  62 #include <sys/ioctl.h>
  63 #include <sys/wait.h>
  64 #include <termios.h>
  65 #include <ctype.h>
  66 #include <setjmp.h>
  67 #include <pwd.h>
  68
  69 #include "ed.h"
  70
  71
  72 #ifdef _POSIX_SOURCE
  73 sigjmp_buf env;
  74 #else
  75 jmp_buf env;
  76 #endif
  77
  78 /* static buffers */
  79 char stdinbuf[1];               /* stdin buffer */
  80 char *shcmd;                    /* shell command buffer */
  81 int shcmdsz;                    /* shell command buffer size */
  82 int shcmdi;                     /* shell command buffer index */
  83 char *ibuf;                     /* ed command-line buffer */
  84 int ibufsz;                     /* ed command-line buffer size */
  85 char *ibufp;                    /* pointer to ed command-line buffer */
  86
  87 /* global flags */
  88 int des = 0;                    /* if set, use crypt(3) for i/o */
  89 int garrulous = 0;              /* if set, print all error messages */
  90 int isbinary;                   /* if set, buffer contains ASCII NULs */
  91 int isglobal;                   /* if set, doing a global command */
  92 int modified;                   /* if set, buffer modified since last write */
  93 int mutex = 0;                  /* if set, signals set "sigflags" */
  94 int red = 0;                    /* if set, restrict shell/directory access */
  95 int ere = 0;                    /* if set, use extended regexes */
  96 int scripted = 0;               /* if set, suppress diagnostics */
  97 int sigflags = 0;               /* if set, signals received while mutex set */
  98 int sigactive = 0;              /* if set, signal handlers are enabled */
  99
 100 char old_filename[MAXPATHLEN + 1] = ""; /* default filename */
 101 long current_addr;              /* current address in editor buffer */
 102 long addr_last;                 /* last address in editor buffer */
 103 int lineno;                     /* script line number */
 104 const char *prompt;                     /* command-line prompt */
 105 const char *dps = "*";          /* default command-line prompt */
 106
 107 const char *usage = "usage: %s [-] [-sxE] [-p string] [name]\n";
 108
 109 /* ed: line editor */
 110 int
 111 main(int ac, char *av[])
 112 {
 113         int c, n;
 114         long status = 0;
 115         volatile int argc = ac;
 116         char ** volatile argv = av;
 117
 118         red = (n = strlen(argv[0])) > 2 && argv[0][n - 3] == 'r';
 119 top:
 120         while ((c = getopt(argc, argv, "p:sxE")) != -1)
 121                 switch(c) {
 122                 case 'p':                               /* set prompt */
 123                         prompt = optarg;
 124                         break;
 125                 case 's':                               /* run script */
 126                         scripted = 1;
 127                         break;
 128                 case 'x':                               /* use crypt */
 129 #ifdef DES
 130                         des = get_keyword();
 131 #else
 132                         fprintf(stderr, "crypt unavailable\n?\n");
 133 #endif
 134                         break;
 135
 136                 case 'E':
 137                         ere = REG_EXTENDED;
 138                         break;
 139                 default:
 140                         fprintf(stderr, usage, argv[0]);
 141                         exit(1);
 142                         /* NOTREACHED */
 143                 }
 144         argv += optind;
 145         argc -= optind;
 146         if (argc && **argv == '-') {
 147                 scripted = 1;
 148                 if (argc > 1) {
 149                         optind = 1;
 150                         goto top;
 151                 }
 152                 argv++;
 153                 argc--;
 154         }
 155         /* assert: reliable signals! */
 156 #ifdef SIGWINCH
 157         handle_winch(SIGWINCH);
 158         if (isatty(0)) signal(SIGWINCH, handle_winch);
 159 #endif
 160         signal(SIGHUP, signal_hup);
 161         signal(SIGQUIT, SIG_IGN);
 162         signal(SIGINT, signal_int);
 163 #ifdef _POSIX_SOURCE
 164         if ((status = sigsetjmp(env, 1)) != 0)
 165 #else
 166         if ((status = setjmp(env)) != 0)
 167 #endif
 168         {
 169                 fputs("\n?\n", stderr);
 170                 sprintf(errmsg, "interrupt");
 171         } else {
 172                 init_buffers();
 173                 sigactive = 1;                  /* enable signal handlers */
 174                 if (argc && **argv && is_legal_filename(*argv)) {
 175                         if (read_file(*argv, 0) < 0 && !isatty(0))
 176                                 quit(2);
 177                         else if (**argv != '!')
 178                                 strlcpy(old_filename, *argv,
 179                                     sizeof(old_filename) - 2);
 180                 } else if (argc) {
 181                         fputs("?\n", stderr);
 182                         if (**argv == '\0')
 183                                 sprintf(errmsg, "invalid filename");
 184                         if (!isatty(0))
 185                                 quit(2);
 186                 }
 187         }
 188         for (;;) {
 189                 if (status < 0 && garrulous)
 190                         fprintf(stderr, "%s\n", errmsg);
 191                 if (prompt) {
 192                         printf("%s", prompt);
 193                         fflush(stdout);
 194                 }
 195                 if ((n = get_tty_line()) < 0) {
 196                         status = ERR;
 197                         continue;
 198                 } else if (n == 0) {
 199                         if (modified && !scripted) {
 200                                 fputs("?\n", stderr);
 201                                 sprintf(errmsg, "warning: file modified");
 202                                 if (!isatty(0)) {
 203                                         fprintf(stderr, garrulous ?
 204                                             "script, line %d: %s\n" :
 205                                             "", lineno, errmsg);
 206                                         quit(2);
 207                                 }
 208                                 clearerr(stdin);
 209                                 modified = 0;
 210                                 status = EMOD;
 211                                 continue;
 212                         } else
 213                                 quit(0);
 214                 } else if (ibuf[n - 1] != '\n') {
 215                         /* discard line */
 216                         sprintf(errmsg, "unexpected end-of-file");
 217                         clearerr(stdin);
 218                         status = ERR;
 219                         continue;
 220                 }
 221                 isglobal = 0;
 222                 if ((status = extract_addr_range()) >= 0 &&
 223                     (status = exec_command()) >= 0)
 224                         if (!status || (status &&
 225                             (status = display_lines(current_addr, current_addr,
 226                                 status))) >= 0)
 227                                 continue;
 228                 switch (status) {
 229                 case EOF:
 230                         quit(0);
 231                 case EMOD:
 232                         modified = 0;
 233                         fputs("?\n", stderr);           /* give warning */
 234                         sprintf(errmsg, "warning: file modified");
 235                         if (!isatty(0)) {
 236                                 fprintf(stderr, garrulous ?
 237                                     "script, line %d: %s\n" :
 238                                     "", lineno, errmsg);
 239                                 quit(2);
 240                         }
 241                         break;
 242                 case FATAL:
 243                         if (!isatty(0))
 244                                 fprintf(stderr, garrulous ?
 245                                     "script, line %d: %s\n" : "",
 246                                     lineno, errmsg);
 247                         else
 248                                 fprintf(stderr, garrulous ? "%s\n" : "",
 249                                     errmsg);
 250                         quit(3);
 251                 default:
 252                         fputs("?\n", stderr);
 253                         if (!isatty(0)) {
 254                                 fprintf(stderr, garrulous ?
 255                                     "script, line %d: %s\n" : "",
 256                                     lineno, errmsg);
 257                                 quit(2);
 258                         }
 259                         break;
 260                 }
 261         }
 262         /* NOTREACHED */
 263 }
 264
 265 long first_addr, second_addr, addr_cnt;
 266
 267 /* extract_addr_range: get line addresses from the command buffer until an
 268    illegal address is seen; return status */
 269 int
 270 extract_addr_range(void)
 271 {
 272         long addr;
 273
 274         addr_cnt = 0;
 275         first_addr = second_addr = current_addr;
 276         while ((addr = next_addr()) >= 0) {
 277                 addr_cnt++;
 278                 first_addr = second_addr;
 279                 second_addr = addr;
 280                 if (*ibufp != ',' && *ibufp != ';')
 281                         break;
 282                 else if (*ibufp++ == ';')
 283                         current_addr = addr;
 284         }
 285         if ((addr_cnt = min(addr_cnt, 2)) == 1 || second_addr != addr)
 286                 first_addr = second_addr;
 287         return (addr == ERR) ? ERR : 0;
 288 }
 289
 290
 291 #define SKIP_BLANKS() while (isspace((unsigned char)*ibufp) && *ibufp != '\n') \
 292         ibufp++
 293
 294 #define MUST_BE_FIRST() \
 295         if (!first) { sprintf(errmsg, "invalid address"); return ERR; }
 296
 297 /*  next_addr: return the next line address in the command buffer */
 298 long
 299 next_addr(void)
 300 {
 301         char *hd;
 302         long addr = current_addr;
 303         long n;
 304         int first = 1;
 305         int c;
 306
 307         SKIP_BLANKS();
 308         for (hd = ibufp;; first = 0)
 309                 switch (c = *ibufp) {
 310                 case '+':
 311                 case '\t':
 312                 case ' ':
 313                 case '-':
 314                 case '^':
 315                         ibufp++;
 316                         SKIP_BLANKS();
 317                         if (isdigit((unsigned char)*ibufp)) {
 318                                 STRTOL(n, ibufp);
 319                                 addr += (c == '-' || c == '^') ? -n : n;
 320                         } else if (!isspace((unsigned char)c))
 321                                 addr += (c == '-' || c == '^') ? -1 : 1;
 322                         break;
 323                 case '0': case '1': case '2':
 324                 case '3': case '4': case '5':
 325                 case '6': case '7': case '8': case '9':
 326                         MUST_BE_FIRST();
 327                         STRTOL(addr, ibufp);
 328                         break;
 329                 case '.':
 330                 case '$':
 331                         MUST_BE_FIRST();
 332                         ibufp++;
 333                         addr = (c == '.') ? current_addr : addr_last;
 334                         break;
 335                 case '/':
 336                 case '?':
 337                         MUST_BE_FIRST();
 338                         if ((addr = get_matching_node_addr(
 339                             get_compiled_pattern(), c == '/')) < 0)
 340                                 return ERR;
 341                         else if (c == *ibufp)
 342                                 ibufp++;
 343                         break;
 344                 case '\'':
 345                         MUST_BE_FIRST();
 346                         ibufp++;
 347                         if ((addr = get_marked_node_addr((unsigned char)*ibufp++)) < 0)
 348                                 return ERR;
 349                         break;
 350                 case '%':
 351                 case ',':
 352                 case ';':
 353                         if (first) {
 354                                 ibufp++;
 355                                 addr_cnt++;
 356                                 second_addr = (c == ';') ? current_addr : 1;
 357                                 addr = addr_last;
 358                                 break;
 359                         }
 360                         /* FALL THROUGH */
 361                 default:
 362                         if (ibufp == hd)
 363                                 return EOF;
 364                         else if (addr < 0 || addr_last < addr) {
 365                                 sprintf(errmsg, "invalid address");
 366                                 return ERR;
 367                         } else
 368                                 return addr;
 369                 }
 370         /* NOTREACHED */
 371 }
 372
 373
 374 #ifdef BACKWARDS
 375 /* GET_THIRD_ADDR: get a legal address from the command buffer */
 376 #define GET_THIRD_ADDR(addr) \
 377 { \
 378         long ol1, ol2; \
 379 \
 380         ol1 = first_addr, ol2 = second_addr; \
 381         if (extract_addr_range() < 0) \
 382                 return ERR; \
 383         else if (addr_cnt == 0) { \
 384                 sprintf(errmsg, "destination expected"); \
 385                 return ERR; \
 386         } else if (second_addr < 0 || addr_last < second_addr) { \
 387                 sprintf(errmsg, "invalid address"); \
 388                 return ERR; \
 389         } \
 390         addr = second_addr; \
 391         first_addr = ol1, second_addr = ol2; \
 392 }
 393 #else   /* BACKWARDS */
 394 /* GET_THIRD_ADDR: get a legal address from the command buffer */
 395 #define GET_THIRD_ADDR(addr) \
 396 { \
 397         long ol1, ol2; \
 398 \
 399         ol1 = first_addr, ol2 = second_addr; \
 400         if (extract_addr_range() < 0) \
 401                 return ERR; \
 402         if (second_addr < 0 || addr_last < second_addr) { \
 403                 sprintf(errmsg, "invalid address"); \
 404                 return ERR; \
 405         } \
 406         addr = second_addr; \
 407         first_addr = ol1, second_addr = ol2; \
 408 }
 409 #endif
 410
 411
 412 /* GET_COMMAND_SUFFIX: verify the command suffix in the command buffer */
 413 #define GET_COMMAND_SUFFIX() { \
 414         int done = 0; \
 415         do { \
 416                 switch(*ibufp) { \
 417                 case 'p': \
 418                         gflag |= GPR, ibufp++; \
 419                         break; \
 420                 case 'l': \
 421                         gflag |= GLS, ibufp++; \
 422                         break; \
 423                 case 'n': \
 424                         gflag |= GNP, ibufp++; \
 425                         break; \
 426                 default: \
 427                         done++; \
 428                 } \
 429         } while (!done); \
 430         if (*ibufp++ != '\n') { \
 431                 sprintf(errmsg, "invalid command suffix"); \
 432                 return ERR; \
 433         } \
 434 }
 435
 436
 437 /* sflags */
 438 #define SGG 001         /* complement previous global substitute suffix */
 439 #define SGP 002         /* complement previous print suffix */
 440 #define SGR 004         /* use last regex instead of last pat */
 441 #define SGF 010         /* repeat last substitution */
 442
 443 int patlock = 0;        /* if set, pattern not freed by get_compiled_pattern() */
 444
 445 long rows = 22;         /* scroll length: ws_row - 2 */
 446
 447 /* exec_command: execute the next command in command buffer; return print
 448    request, if any */
 449 int
 450 exec_command(void)
 451 {
 452         static pattern_t *pat = NULL;
 453         static int sgflag = 0;
 454         static long sgnum = 0;
 455
 456         pattern_t *tpat;
 457         char *fnp;
 458         int gflag = 0;
 459         int sflags = 0;
 460         long addr = 0;
 461         int n = 0;
 462         int c;
 463
 464         SKIP_BLANKS();
 465         switch(c = *ibufp++) {
 466         case 'a':
 467                 GET_COMMAND_SUFFIX();
 468                 if (!isglobal) clear_undo_stack();
 469                 if (append_lines(second_addr) < 0)
 470                         return ERR;
 471                 break;
 472         case 'c':
 473                 if (check_addr_range(current_addr, current_addr) < 0)
 474                         return ERR;
 475                 GET_COMMAND_SUFFIX();
 476                 if (!isglobal) clear_undo_stack();
 477                 if (delete_lines(first_addr, second_addr) < 0 ||
 478                     append_lines(current_addr) < 0)
 479                         return ERR;
 480                 break;
 481         case 'd':
 482                 if (check_addr_range(current_addr, current_addr) < 0)
 483                         return ERR;
 484                 GET_COMMAND_SUFFIX();
 485                 if (!isglobal) clear_undo_stack();
 486                 if (delete_lines(first_addr, second_addr) < 0)
 487                         return ERR;
 488                 else if ((addr = INC_MOD(current_addr, addr_last)) != 0)
 489                         current_addr = addr;
 490                 break;
 491         case 'e':
 492                 if (modified && !scripted)
 493                         return EMOD;
 494                 /* fall through */
 495         case 'E':
 496                 if (addr_cnt > 0) {
 497                         sprintf(errmsg, "unexpected address");
 498                         return ERR;
 499                 } else if (!isspace((unsigned char)*ibufp)) {
 500                         sprintf(errmsg, "unexpected command suffix");
 501                         return ERR;
 502                 } else if ((fnp = get_filename()) == NULL)
 503                         return ERR;
 504                 GET_COMMAND_SUFFIX();
 505                 if (delete_lines(1, addr_last) < 0)
 506                         return ERR;
 507                 clear_undo_stack();
 508                 if (close_sbuf() < 0)
 509                         return ERR;
 510                 else if (open_sbuf() < 0)
 511                         return FATAL;
 512                 if (*fnp && *fnp != '!') strlcpy(old_filename, fnp,
 513                         sizeof(old_filename) - 2);
 514 #ifdef BACKWARDS
 515                 if (*fnp == '\0' && *old_filename == '\0') {
 516                         sprintf(errmsg, "no current filename");
 517                         return ERR;
 518                 }
 519 #endif
 520                 if (read_file(*fnp ? fnp : old_filename, 0) < 0)
 521                         return ERR;
 522                 clear_undo_stack();
 523                 modified = 0;
 524                 u_current_addr = u_addr_last = -1;
 525                 break;
 526         case 'f':
 527                 if (addr_cnt > 0) {
 528                         sprintf(errmsg, "unexpected address");
 529                         return ERR;
 530                 } else if (!isspace((unsigned char)*ibufp)) {
 531                         sprintf(errmsg, "unexpected command suffix");
 532                         return ERR;
 533                 } else if ((fnp = get_filename()) == NULL)
 534                         return ERR;
 535                 else if (*fnp == '!') {
 536                         sprintf(errmsg, "invalid redirection");
 537                         return ERR;
 538                 }
 539                 GET_COMMAND_SUFFIX();
 540                 if (*fnp) strlcpy(old_filename, fnp, sizeof(old_filename) - 2);
 541                 printf("%s\n", strip_escapes(old_filename));
 542                 break;
 543         case 'g':
 544         case 'v':
 545         case 'G':
 546         case 'V':
 547                 if (isglobal) {
 548                         sprintf(errmsg, "cannot nest global commands");
 549                         return ERR;
 550                 } else if (check_addr_range(1, addr_last) < 0)
 551                         return ERR;
 552                 else if (build_active_list(c == 'g' || c == 'G') < 0)
 553                         return ERR;
 554                 else if ((n = (c == 'G' || c == 'V')) != 0)
 555                         GET_COMMAND_SUFFIX();
 556                 isglobal++;
 557                 if (exec_global(n, gflag) < 0)
 558                         return ERR;
 559                 break;
 560         case 'h':
 561                 if (addr_cnt > 0) {
 562                         sprintf(errmsg, "unexpected address");
 563                         return ERR;
 564                 }
 565                 GET_COMMAND_SUFFIX();
 566                 if (*errmsg) fprintf(stderr, "%s\n", errmsg);
 567                 break;
 568         case 'H':
 569                 if (addr_cnt > 0) {
 570                         sprintf(errmsg, "unexpected address");
 571                         return ERR;
 572                 }
 573                 GET_COMMAND_SUFFIX();
 574                 if ((garrulous = 1 - garrulous) && *errmsg)
 575                         fprintf(stderr, "%s\n", errmsg);
 576                 break;
 577         case 'i':
 578                 if (second_addr == 0) {
 579                         sprintf(errmsg, "invalid address");
 580                         return ERR;
 581                 }
 582                 GET_COMMAND_SUFFIX();
 583                 if (!isglobal) clear_undo_stack();
 584                 if (append_lines(second_addr - 1) < 0)
 585                         return ERR;
 586                 break;
 587         case 'j':
 588                 if (check_addr_range(current_addr, current_addr + 1) < 0)
 589                         return ERR;
 590                 GET_COMMAND_SUFFIX();
 591                 if (!isglobal) clear_undo_stack();
 592                 if (first_addr != second_addr &&
 593                     join_lines(first_addr, second_addr) < 0)
 594                         return ERR;
 595                 break;
 596         case 'k':
 597                 c = *ibufp++;
 598                 if (second_addr == 0) {
 599                         sprintf(errmsg, "invalid address");
 600                         return ERR;
 601                 }
 602                 GET_COMMAND_SUFFIX();
 603                 if (mark_line_node(get_addressed_line_node(second_addr), (unsigned char)c) < 0)
 604                         return ERR;
 605                 break;
 606         case 'l':
 607                 if (check_addr_range(current_addr, current_addr) < 0)
 608                         return ERR;
 609                 GET_COMMAND_SUFFIX();
 610                 if (display_lines(first_addr, second_addr, gflag | GLS) < 0)
 611                         return ERR;
 612                 gflag = 0;
 613                 break;
 614         case 'm':
 615                 if (check_addr_range(current_addr, current_addr) < 0)
 616                         return ERR;
 617                 GET_THIRD_ADDR(addr);
 618                 if (first_addr <= addr && addr < second_addr) {
 619                         sprintf(errmsg, "invalid destination");
 620                         return ERR;
 621                 }
 622                 GET_COMMAND_SUFFIX();
 623                 if (!isglobal) clear_undo_stack();
 624                 if (move_lines(addr) < 0)
 625                         return ERR;
 626                 break;
 627         case 'n':
 628                 if (check_addr_range(current_addr, current_addr) < 0)
 629                         return ERR;
 630                 GET_COMMAND_SUFFIX();
 631                 if (display_lines(first_addr, second_addr, gflag | GNP) < 0)
 632                         return ERR;
 633                 gflag = 0;
 634                 break;
 635         case 'p':
 636                 if (check_addr_range(current_addr, current_addr) < 0)
 637                         return ERR;
 638                 GET_COMMAND_SUFFIX();
 639                 if (display_lines(first_addr, second_addr, gflag | GPR) < 0)
 640                         return ERR;
 641                 gflag = 0;
 642                 break;
 643         case 'P':
 644                 if (addr_cnt > 0) {
 645                         sprintf(errmsg, "unexpected address");
 646                         return ERR;
 647                 }
 648                 GET_COMMAND_SUFFIX();
 649                 prompt = prompt ? NULL : optarg ? optarg : dps;
 650                 break;
 651         case 'q':
 652         case 'Q':
 653                 if (addr_cnt > 0) {
 654                         sprintf(errmsg, "unexpected address");
 655                         return ERR;
 656                 }
 657                 GET_COMMAND_SUFFIX();
 658                 gflag =  (modified && !scripted && c == 'q') ? EMOD : EOF;
 659                 break;
 660         case 'r':
 661                 if (!isspace((unsigned char)*ibufp)) {
 662                         sprintf(errmsg, "unexpected command suffix");
 663                         return ERR;
 664                 } else if (addr_cnt == 0)
 665                         second_addr = addr_last;
 666                 if ((fnp = get_filename()) == NULL)
 667                         return ERR;
 668                 GET_COMMAND_SUFFIX();
 669                 if (!isglobal) clear_undo_stack();
 670                 if (*old_filename == '\0' && *fnp != '!')
 671                         strlcpy(old_filename, fnp, sizeof(old_filename) - 2);
 672 #ifdef BACKWARDS
 673                 if (*fnp == '\0' && *old_filename == '\0') {
 674                         sprintf(errmsg, "no current filename");
 675                         return ERR;
 676                 }
 677 #endif
 678                 if ((addr = read_file(*fnp ? fnp : old_filename, second_addr)) < 0)
 679                         return ERR;
 680                 else if (addr && addr != addr_last)
 681                         modified = 1;
 682                 break;
 683         case 's':
 684                 do {
 685                         switch(*ibufp) {
 686                         case '\n':
 687                                 sflags |=SGF;
 688                                 break;
 689                         case 'g':
 690                                 sflags |= SGG;
 691                                 ibufp++;
 692                                 break;
 693                         case 'p':
 694                                 sflags |= SGP;
 695                                 ibufp++;
 696                                 break;
 697                         case 'r':
 698                                 sflags |= SGR;
 699                                 ibufp++;
 700                                 break;
 701                         case '0': case '1': case '2': case '3': case '4':
 702                         case '5': case '6': case '7': case '8': case '9':
 703                                 STRTOL(sgnum, ibufp);
 704                                 sflags |= SGF;
 705                                 sgflag &= ~GSG;         /* override GSG */
 706                                 break;
 707                         default:
 708                                 if (sflags) {
 709                                         sprintf(errmsg, "invalid command suffix");
 710                                         return ERR;
 711                                 }
 712                         }
 713                 } while (sflags && *ibufp != '\n');
 714                 if (sflags && !pat) {
 715                         sprintf(errmsg, "no previous substitution");
 716                         return ERR;
 717                 } else if (sflags & SGG)
 718                         sgnum = 0;              /* override numeric arg */
 719                 if (*ibufp != '\n' && *(ibufp + 1) == '\n') {
 720                         sprintf(errmsg, "invalid pattern delimiter");
 721                         return ERR;
 722                 }
 723                 tpat = pat;
 724                 SPL1();
 725                 if ((!sflags || (sflags & SGR)) &&
 726                     (tpat = get_compiled_pattern()) == NULL) {
 727                         SPL0();
 728                         return ERR;
 729                 } else if (tpat != pat) {
 730                         if (pat) {
 731                                 regfree(pat);
 732                                 free(pat);
 733                         }
 734                         pat = tpat;
 735                         patlock = 1;            /* reserve pattern */
 736                 }
 737                 SPL0();
 738                 if (!sflags && extract_subst_tail(&sgflag, &sgnum) < 0)
 739                         return ERR;
 740                 else if (isglobal)
 741                         sgflag |= GLB;
 742                 else
 743                         sgflag &= ~GLB;
 744                 if (sflags & SGG)
 745                         sgflag ^= GSG;
 746                 if (sflags & SGP)
 747                         sgflag ^= GPR, sgflag &= ~(GLS | GNP);
 748                 do {
 749                         switch(*ibufp) {
 750                         case 'p':
 751                                 sgflag |= GPR, ibufp++;
 752                                 break;
 753                         case 'l':
 754                                 sgflag |= GLS, ibufp++;
 755                                 break;
 756                         case 'n':
 757                                 sgflag |= GNP, ibufp++;
 758                                 break;
 759                         default:
 760                                 n++;
 761                         }
 762                 } while (!n);
 763                 if (check_addr_range(current_addr, current_addr) < 0)
 764                         return ERR;
 765                 GET_COMMAND_SUFFIX();
 766                 if (!isglobal) clear_undo_stack();
 767                 if (search_and_replace(pat, sgflag, sgnum) < 0)
 768                         return ERR;
 769                 break;
 770         case 't':
 771                 if (check_addr_range(current_addr, current_addr) < 0)
 772                         return ERR;
 773                 GET_THIRD_ADDR(addr);
 774                 GET_COMMAND_SUFFIX();
 775                 if (!isglobal) clear_undo_stack();
 776                 if (copy_lines(addr) < 0)
 777                         return ERR;
 778                 break;
 779         case 'u':
 780                 if (addr_cnt > 0) {
 781                         sprintf(errmsg, "unexpected address");
 782                         return ERR;
 783                 }
 784                 GET_COMMAND_SUFFIX();
 785                 if (pop_undo_stack() < 0)
 786                         return ERR;
 787                 break;
 788         case 'w':
 789         case 'W':
 790                 if ((n = *ibufp) == 'q' || n == 'Q') {
 791                         gflag = EOF;
 792                         ibufp++;
 793                 }
 794                 if (!isspace((unsigned char)*ibufp)) {
 795                         sprintf(errmsg, "unexpected command suffix");
 796                         return ERR;
 797                 } else if ((fnp = get_filename()) == NULL)
 798                         return ERR;
 799                 if (addr_cnt == 0 && !addr_last)
 800                         first_addr = second_addr = 0;
 801                 else if (check_addr_range(1, addr_last) < 0)
 802                         return ERR;
 803                 GET_COMMAND_SUFFIX();
 804                 if (*old_filename == '\0' && *fnp != '!')
 805                         strlcpy(old_filename, fnp, sizeof(old_filename) - 2);
 806 #ifdef BACKWARDS
 807                 if (*fnp == '\0' && *old_filename == '\0') {
 808                         sprintf(errmsg, "no current filename");
 809                         return ERR;
 810                 }
 811 #endif
 812                 if ((addr = write_file(*fnp ? fnp : old_filename,
 813                     (c == 'W') ? "a" : "w", first_addr, second_addr)) < 0)
 814                         return ERR;
 815                 else if (addr == addr_last)
 816                         modified = 0;
 817                 else if (modified && !scripted && n == 'q')
 818                         gflag = EMOD;
 819                 break;
 820         case 'x':
 821                 if (addr_cnt > 0) {
 822                         sprintf(errmsg, "unexpected address");
 823                         return ERR;
 824                 }
 825                 GET_COMMAND_SUFFIX();
 826 #ifdef DES
 827                 des = get_keyword();
 828 #else
 829                 sprintf(errmsg, "crypt unavailable");
 830                 return ERR;
 831 #endif
 832                 break;
 833         case 'z':
 834 #ifdef BACKWARDS
 835                 if (check_addr_range(first_addr = 1, current_addr + 1) < 0)
 836 #else
 837                 if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0)
 838 #endif
 839                         return ERR;
 840                 else if ('0' < *ibufp && *ibufp <= '9')
 841                         STRTOL(rows, ibufp);
 842                 GET_COMMAND_SUFFIX();
 843                 if (display_lines(second_addr, min(addr_last,
 844                     second_addr + rows), gflag) < 0)
 845                         return ERR;
 846                 gflag = 0;
 847                 break;
 848         case '=':
 849                 GET_COMMAND_SUFFIX();
 850                 printf("%ld\n", addr_cnt ? second_addr : addr_last);
 851                 break;
 852         case '!':
 853                 if (addr_cnt > 0) {
 854                         sprintf(errmsg, "unexpected address");
 855                         return ERR;
 856                 } else if ((sflags = get_shell_command()) < 0)
 857                         return ERR;
 858                 GET_COMMAND_SUFFIX();
 859                 if (sflags) printf("%s\n", shcmd + 1);
 860                 system(shcmd + 1);
 861                 if (!scripted) printf("!\n");
 862                 break;
 863         case '\n':
 864 #ifdef BACKWARDS
 865                 if (check_addr_range(first_addr = 1, current_addr + 1) < 0
 866 #else
 867                 if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0
 868 #endif
 869                  || display_lines(second_addr, second_addr, 0) < 0)
 870                         return ERR;
 871                 break;
 872         default:
 873                 sprintf(errmsg, "unknown command");
 874                 return ERR;
 875         }
 876         return gflag;
 877 }
 878
 879
 880 /* check_addr_range: return status of address range check */
 881 int
 882 check_addr_range(long n, long m)
 883 {
 884         if (addr_cnt == 0) {
 885                 first_addr = n;
 886                 second_addr = m;
 887         }
 888         if (first_addr > second_addr || 1 > first_addr ||
 889             second_addr > addr_last) {
 890                 sprintf(errmsg, "invalid address");
 891                 return ERR;
 892         }
 893         return 0;
 894 }
 895
 896
 897 /* get_matching_node_addr: return the address of the next line matching a
 898    pattern in a given direction.  wrap around begin/end of editor buffer if
 899    necessary */
 900 long
 901 get_matching_node_addr(pattern_t *pat, int dir)
 902 {
 903         char *s;
 904         long n = current_addr;
 905         line_t *lp;
 906
 907         if (!pat) return ERR;
 908         do {
 909                 if ((n = dir ? INC_MOD(n, addr_last) :
 910                     DEC_MOD(n, addr_last)) != 0) {
 911                         lp = get_addressed_line_node(n);
 912                         if ((s = get_sbuf_line(lp)) == NULL)
 913                                 return ERR;
 914                         if (isbinary)
 915                                 NUL_TO_NEWLINE(s, lp->len);
 916                         if (!regexec(pat, s, 0, NULL, 0))
 917                                 return n;
 918                 }
 919         } while (n != current_addr);
 920         sprintf(errmsg, "no match");
 921         return  ERR;
 922 }
 923
 924
 925 /* get_filename: return pointer to copy of filename in the command buffer */
 926 char *
 927 get_filename(void)
 928 {
 929         static char *file = NULL;
 930         static int filesz = 0;
 931
 932         int n;
 933
 934         if (*ibufp != '\n') {
 935                 SKIP_BLANKS();
 936                 if (*ibufp == '\n') {
 937                         sprintf(errmsg, "invalid filename");
 938                         return NULL;
 939                 } else if ((ibufp = get_extended_line(&n, 1)) == NULL)
 940                         return NULL;
 941                 else if (*ibufp == '!') {
 942                         ibufp++;
 943                         if ((n = get_shell_command()) < 0)
 944                                 return NULL;
 945                         if (n) printf("%s\n", shcmd + 1);
 946                         return shcmd;
 947                 } else if (n - 1 > MAXPATHLEN) {
 948                         sprintf(errmsg, "filename too long");
 949                         return  NULL;
 950                 }
 951         }
 952 #ifndef BACKWARDS
 953         else if (*old_filename == '\0') {
 954                 sprintf(errmsg, "no current filename");
 955                 return  NULL;
 956         }
 957 #endif
 958         REALLOC(file, filesz, MAXPATHLEN + 1, NULL);
 959         for (n = 0; *ibufp != '\n';)
 960                 file[n++] = *ibufp++;
 961         file[n] = '\0';
 962         return is_legal_filename(file) ? file : NULL;
 963 }
 964
 965
 966 /* get_shell_command: read a shell command from stdin; return substitution
 967    status */
 968 int
 969 get_shell_command(void)
 970 {
 971         static char *buf = NULL;
 972         static int n = 0;
 973
 974         char *s;                        /* substitution char pointer */
 975         int i = 0;
 976         int j = 0;
 977
 978         if (red) {
 979                 sprintf(errmsg, "shell access restricted");
 980                 return ERR;
 981         } else if ((s = ibufp = get_extended_line(&j, 1)) == NULL)
 982                 return ERR;
 983         REALLOC(buf, n, j + 1, ERR);
 984         buf[i++] = '!';                 /* prefix command w/ bang */
 985         while (*ibufp != '\n')
 986                 switch (*ibufp) {
 987                 default:
 988                         REALLOC(buf, n, i + 2, ERR);
 989                         buf[i++] = *ibufp;
 990                         if (*ibufp++ == '\\')
 991                                 buf[i++] = *ibufp++;
 992                         break;
 993                 case '!':
 994                         if (s != ibufp) {
 995                                 REALLOC(buf, n, i + 1, ERR);
 996                                 buf[i++] = *ibufp++;
 997                         }
 998 #ifdef BACKWARDS
 999                         else if (shcmd == NULL || *(shcmd + 1) == '\0')
1000 #else
1001                         else if (shcmd == NULL)
1002 #endif
1003                         {
1004                                 sprintf(errmsg, "no previous command");
1005                                 return ERR;
1006                         } else {
1007                                 REALLOC(buf, n, i + shcmdi, ERR);
1008                                 for (s = shcmd + 1; s < shcmd + shcmdi;)
1009                                         buf[i++] = *s++;
1010                                 s = ibufp++;
1011                         }
1012                         break;
1013                 case '%':
1014                         if (*old_filename  == '\0') {
1015                                 sprintf(errmsg, "no current filename");
1016                                 return ERR;
1017                         }
1018                         j = strlen(s = strip_escapes(old_filename));
1019                         REALLOC(buf, n, i + j, ERR);
1020                         while (j--)
1021                                 buf[i++] = *s++;
1022                         s = ibufp++;
1023                         break;
1024                 }
1025         REALLOC(shcmd, shcmdsz, i + 1, ERR);
1026         memcpy(shcmd, buf, i);
1027         shcmd[shcmdi = i] = '\0';
1028         return *s == '!' || *s == '%';
1029 }
1030
1031
1032 /* append_lines: insert text from stdin to after line n; stop when either a
1033    single period is read or EOF; return status */
1034 int
1035 append_lines(long n)
1036 {
1037         int l;
1038         char *lp = ibuf;
1039         char *eot;
1040         undo_t *up = NULL;
1041
1042         for (current_addr = n;;) {
1043                 if (!isglobal) {
1044                         if ((l = get_tty_line()) < 0)
1045                                 return ERR;
1046                         else if (l == 0 || ibuf[l - 1] != '\n') {
1047                                 clearerr(stdin);
1048                                 return  l ? EOF : 0;
1049                         }
1050                         lp = ibuf;
1051                 } else if (*(lp = ibufp) == '\0')
1052                         return 0;
1053                 else {
1054                         while (*ibufp++ != '\n')
1055                                 ;
1056                         l = ibufp - lp;
1057                 }
1058                 if (l == 2 && lp[0] == '.' && lp[1] == '\n') {
1059                         return 0;
1060                 }
1061                 eot = lp + l;
1062                 SPL1();
1063                 do {
1064                         if ((lp = put_sbuf_line(lp)) == NULL) {
1065                                 SPL0();
1066                                 return ERR;
1067                         } else if (up)
1068                                 up->t = get_addressed_line_node(current_addr);
1069                         else if ((up = push_undo_stack(UADD, current_addr,
1070                             current_addr)) == NULL) {
1071                                 SPL0();
1072                                 return ERR;
1073                         }
1074                 } while (lp != eot);
1075                 modified = 1;
1076                 SPL0();
1077         }
1078         /* NOTREACHED */
1079 }
1080
1081
1082 /* join_lines: replace a range of lines with the joined text of those lines */
1083 int
1084 join_lines(long from, long to)
1085 {
1086         static char *buf = NULL;
1087         static int n;
1088
1089         char *s;
1090         int size = 0;
1091         line_t *bp, *ep;
1092
1093         ep = get_addressed_line_node(INC_MOD(to, addr_last));
1094         bp = get_addressed_line_node(from);
1095         for (; bp != ep; bp = bp->q_forw) {
1096                 if ((s = get_sbuf_line(bp)) == NULL)
1097                         return ERR;
1098                 REALLOC(buf, n, size + bp->len, ERR);
1099                 memcpy(buf + size, s, bp->len);
1100                 size += bp->len;
1101         }
1102         REALLOC(buf, n, size + 2, ERR);
1103         memcpy(buf + size, "\n", 2);
1104         if (delete_lines(from, to) < 0)
1105                 return ERR;
1106         current_addr = from - 1;
1107         SPL1();
1108         if (put_sbuf_line(buf) == NULL ||
1109             push_undo_stack(UADD, current_addr, current_addr) == NULL) {
1110                 SPL0();
1111                 return ERR;
1112         }
1113         modified = 1;
1114         SPL0();
1115         return 0;
1116 }
1117
1118
1119 /* move_lines: move a range of lines */
1120 int
1121 move_lines(long addr)
1122 {
1123         line_t *b1, *a1, *b2, *a2;
1124         long n = INC_MOD(second_addr, addr_last);
1125         long p = first_addr - 1;
1126         int done = (addr == first_addr - 1 || addr == second_addr);
1127
1128         SPL1();
1129         if (done) {
1130                 a2 = get_addressed_line_node(n);
1131                 b2 = get_addressed_line_node(p);
1132                 current_addr = second_addr;
1133         } else if (push_undo_stack(UMOV, p, n) == NULL ||
1134             push_undo_stack(UMOV, addr, INC_MOD(addr, addr_last)) == NULL) {
1135                 SPL0();
1136                 return ERR;
1137         } else {
1138                 a1 = get_addressed_line_node(n);
1139                 if (addr < first_addr) {
1140                         b1 = get_addressed_line_node(p);
1141                         b2 = get_addressed_line_node(addr);
1142                                         /* this get_addressed_line_node last! */
1143                 } else {
1144                         b2 = get_addressed_line_node(addr);
1145                         b1 = get_addressed_line_node(p);
1146                                         /* this get_addressed_line_node last! */
1147                 }
1148                 a2 = b2->q_forw;
1149                 REQUE(b2, b1->q_forw);
1150                 REQUE(a1->q_back, a2);
1151                 REQUE(b1, a1);
1152                 current_addr = addr + ((addr < first_addr) ?
1153                     second_addr - first_addr + 1 : 0);
1154         }
1155         if (isglobal)
1156                 unset_active_nodes(b2->q_forw, a2);
1157         modified = 1;
1158         SPL0();
1159         return 0;
1160 }
1161
1162
1163 /* copy_lines: copy a range of lines; return status */
1164 int
1165 copy_lines(long addr)
1166 {
1167         line_t *lp, *np = get_addressed_line_node(first_addr);
1168         undo_t *up = NULL;
1169         long n = second_addr - first_addr + 1;
1170         long m = 0;
1171
1172         current_addr = addr;
1173         if (first_addr <= addr && addr < second_addr) {
1174                 n =  addr - first_addr + 1;
1175                 m = second_addr - addr;
1176         }
1177         for (; n > 0; n=m, m=0, np = get_addressed_line_node(current_addr + 1))
1178                 for (; n-- > 0; np = np->q_forw) {
1179                         SPL1();
1180                         if ((lp = dup_line_node(np)) == NULL) {
1181                                 SPL0();
1182                                 return ERR;
1183                         }
1184                         add_line_node(lp);
1185                         if (up)
1186                                 up->t = lp;
1187                         else if ((up = push_undo_stack(UADD, current_addr,
1188                             current_addr)) == NULL) {
1189                                 SPL0();
1190                                 return ERR;
1191                         }
1192                         modified = 1;
1193                         SPL0();
1194                 }
1195         return 0;
1196 }
1197
1198
1199 /* delete_lines: delete a range of lines */
1200 int
1201 delete_lines(long from, long to)
1202 {
1203         line_t *n, *p;
1204
1205         SPL1();
1206         if (push_undo_stack(UDEL, from, to) == NULL) {
1207                 SPL0();
1208                 return ERR;
1209         }
1210         n = get_addressed_line_node(INC_MOD(to, addr_last));
1211         p = get_addressed_line_node(from - 1);
1212                                         /* this get_addressed_line_node last! */
1213         if (isglobal)
1214                 unset_active_nodes(p->q_forw, n);
1215         REQUE(p, n);
1216         addr_last -= to - from + 1;
1217         current_addr = from - 1;
1218         modified = 1;
1219         SPL0();
1220         return 0;
1221 }
1222
1223
1224 /* display_lines: print a range of lines to stdout */
1225 int
1226 display_lines(long from, long to, int gflag)
1227 {
1228         line_t *bp;
1229         line_t *ep;
1230         char *s;
1231
1232         if (!from) {
1233                 sprintf(errmsg, "invalid address");
1234                 return ERR;
1235         }
1236         ep = get_addressed_line_node(INC_MOD(to, addr_last));
1237         bp = get_addressed_line_node(from);
1238         for (; bp != ep; bp = bp->q_forw) {
1239                 if ((s = get_sbuf_line(bp)) == NULL)
1240                         return ERR;
1241                 if (put_tty_line(s, bp->len, current_addr = from++, gflag) < 0)
1242                         return ERR;
1243         }
1244         return 0;
1245 }
1246
1247
1248 #define MAXMARK 26                      /* max number of marks */
1249
1250 line_t  *mark[MAXMARK];                 /* line markers */
1251 int markno;                             /* line marker count */
1252
1253 /* mark_line_node: set a line node mark */
1254 int
1255 mark_line_node(line_t *lp, int n)
1256 {
1257         if (!islower(n)) {
1258                 sprintf(errmsg, "invalid mark character");
1259                 return ERR;
1260         } else if (mark[n - 'a'] == NULL)
1261                 markno++;
1262         mark[n - 'a'] = lp;
1263         return 0;
1264 }
1265
1266
1267 /* get_marked_node_addr: return address of a marked line */
1268 long
1269 get_marked_node_addr(int n)
1270 {
1271         if (!islower(n)) {
1272                 sprintf(errmsg, "invalid mark character");
1273                 return ERR;
1274         }
1275         return get_line_node_addr(mark[n - 'a']);
1276 }
1277
1278
1279 /* unmark_line_node: clear line node mark */
1280 void
1281 unmark_line_node(line_t *lp)
1282 {
1283         int i;
1284
1285         for (i = 0; markno && i < MAXMARK; i++)
1286                 if (mark[i] == lp) {
1287                         mark[i] = NULL;
1288                         markno--;
1289                 }
1290 }
1291
1292
1293 /* dup_line_node: return a pointer to a copy of a line node */
1294 line_t *
1295 dup_line_node(line_t *lp)
1296 {
1297         line_t *np;
1298
1299         if ((np = (line_t *) malloc(sizeof(line_t))) == NULL) {
1300                 fprintf(stderr, "%s\n", strerror(errno));
1301                 sprintf(errmsg, "out of memory");
1302                 return NULL;
1303         }
1304         np->seek = lp->seek;
1305         np->len = lp->len;
1306         return np;
1307 }
1308
1309
1310 /* has_trailing_escape:  return the parity of escapes preceding a character
1311    in a string */
1312 int
1313 has_trailing_escape(char *s, char *t)
1314 {
1315     return (s == t || *(t - 1) != '\\') ? 0 : !has_trailing_escape(s, t - 1);
1316 }
1317
1318
1319 /* strip_escapes: return copy of escaped string of at most length MAXPATHLEN */
1320 char *
1321 strip_escapes(const char *s)
1322 {
1323         static char *file = NULL;
1324         static int filesz = 0;
1325
1326         int i = 0;
1327
1328         REALLOC(file, filesz, MAXPATHLEN + 1, NULL);
1329         while ((i < (filesz - 1)) &&
1330                (file[i++] = (*s == '\\') != '\0' ? *++s : *s))
1331                 s++;
1332         file[filesz - 1] = '\0';
1333         return file;
1334 }
1335
1336
1337 void
1338 signal_hup(int signo)
1339 {
1340         if (mutex)
1341                 sigflags |= (1 << (signo - 1));
1342         else    handle_hup(signo);
1343 }
1344
1345
1346 void
1347 signal_int(int signo)
1348 {
1349         if (mutex)
1350                 sigflags |= (1 << (signo - 1));
1351         else    handle_int(signo);
1352 }
1353
1354
1355 void
1356 handle_hup(int signo)
1357 {
1358         char *hup = NULL;               /* hup filename */
1359         char *s;
1360         int n;
1361
1362         if (!sigactive)
1363                 quit(1);
1364         sigflags &= ~(1 << (signo - 1));
1365         if (addr_last && write_file("ed.hup", "w", 1, addr_last) < 0 &&
1366             (s = getenv("HOME")) != NULL &&
1367             (n = strlen(s)) + 8 <= MAXPATHLEN &&        /* "ed.hup" + '/' */
1368             (hup = (char *) malloc(n + 10)) != NULL) {
1369                 strcpy(hup, s);
1370                 if (hup[n - 1] != '/')
1371                         hup[n] = '/', hup[n+1] = '\0';
1372                 strcat(hup, "ed.hup");
1373                 write_file(hup, "w", 1, addr_last);
1374         }
1375         quit(2);
1376 }
1377
1378
1379 void
1380 handle_int(int signo)
1381 {
1382         if (!sigactive)
1383                 quit(1);
1384         sigflags &= ~(1 << (signo - 1));
1385 #ifdef _POSIX_SOURCE
1386         siglongjmp(env, -1);
1387 #else
1388         longjmp(env, -1);
1389 #endif
1390 }
1391
1392
1393 int cols = 72;                          /* wrap column */
1394
1395 void
1396 handle_winch(int signo)
1397 {
1398         struct winsize ws;              /* window size structure */
1399
1400         sigflags &= ~(1 << (signo - 1));
1401         if (ioctl(0, TIOCGWINSZ, (char *) &ws) >= 0) {
1402                 if (ws.ws_row > 2) rows = ws.ws_row - 2;
1403                 if (ws.ws_col > 8) cols = ws.ws_col - 8;
1404         }
1405 }
1406
1407
1408 /* is_legal_filename: return a legal filename */
1409 int
1410 is_legal_filename(char *s)
1411 {
1412         if (red && (*s == '!' || !strcmp(s, "..") || strchr(s, '/'))) {
1413                 sprintf(errmsg, "shell access restricted");
1414                 return 0;
1415         }
1416         return 1;
1417 }