bin/ed/main.c

   1 /*      $NetBSD: main.c,v 1.28.8.2 2018/06/22 10:08:22 martin 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 1.28.8.2 2018/06/22 10:08:22 martin 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 secure = 0;                 /* is set, ! is not allowed */
  98 int sigflags = 0;               /* if set, signals received while mutex set */
  99 int sigactive = 0;              /* if set, signal handlers are enabled */
 100
 101 char old_filename[MAXPATHLEN + 1] = ""; /* default filename */
 102 long current_addr;              /* current address in editor buffer */
 103 long addr_last;                 /* last address in editor buffer */
 104 int lineno;                     /* script line number */
 105 const char *prompt;                     /* command-line prompt */
 106 const char *dps = "*";          /* default command-line prompt */
 107
 108
 109 static const char usage[] = "Usage: %s [-] [-ESsx] [-p string] [name]\n";
 110
 111 /* ed: line editor */
 112 int
 113 main(int ac, char *av[])
 114 {
 115         int c, n;
 116         long status = 0;
 117         volatile int argc = ac;
 118         char ** volatile argv = av;
 119
 120         red = (n = strlen(argv[0])) > 2 && argv[0][n - 3] == 'r';
 121 top:
 122         while ((c = getopt(argc, argv, "p:sxES")) != -1)
 123                 switch(c) {
 124                 case 'p':                               /* set prompt */
 125                         prompt = optarg;
 126                         break;
 127                 case 's':                               /* run script */
 128                         scripted = 1;
 129                         break;
 130                 case 'x':                               /* use crypt */
 131 #ifdef DES
 132                         des = get_keyword();
 133 #else
 134                         fprintf(stderr, "crypt unavailable\n?\n");
 135 #endif
 136                         break;
 137
 138                 case 'E':
 139                         ere = REG_EXTENDED;
 140                         break;
 141                 case 'S':                               /* ! is not allowed */
 142                         secure = 1;
 143                         break;
 144                 default:
 145                         fprintf(stderr, usage, getprogname());
 146                         exit(1);
 147                         /* NOTREACHED */
 148                 }
 149         argv += optind;
 150         argc -= optind;
 151         if (argc && **argv == '-') {
 152                 scripted = 1;
 153                 if (argc > 1) {
 154                         optind = 1;
 155                         goto top;
 156                 }
 157                 argv++;
 158                 argc--;
 159         }
 160         /* assert: reliable signals! */
 161 #ifdef SIGWINCH
 162         handle_winch(SIGWINCH);
 163         if (isatty(0)) signal(SIGWINCH, handle_winch);
 164 #endif
 165         signal(SIGHUP, signal_hup);
 166         signal(SIGQUIT, SIG_IGN);
 167         signal(SIGINT, signal_int);
 168 #ifdef _POSIX_SOURCE
 169         if ((status = sigsetjmp(env, 1)) != 0)
 170 #else
 171         if ((status = setjmp(env)) != 0)
 172 #endif
 173         {
 174                 fputs("\n?\n", stderr);
 175                 seterrmsg("interrupt");
 176         } else {
 177                 init_buffers();
 178                 sigactive = 1;                  /* enable signal handlers */
 179                 if (argc && **argv && is_legal_filename(*argv)) {
 180                         if (read_file(*argv, 0) < 0 && !isatty(0))
 181                                 quit(2);
 182                         else if (**argv != '!')
 183                                 strlcpy(old_filename, *argv,
 184                                     sizeof(old_filename) - 2);
 185                 } else if (argc) {
 186                         fputs("?\n", stderr);
 187                         if (**argv == '\0')
 188                                 seterrmsg("invalid filename");
 189                         if (!isatty(0))
 190                                 quit(2);
 191                 }
 192         }
 193         for (;;) {
 194                 if (status < 0 && garrulous)
 195                         fprintf(stderr, "%s\n", errmsg);
 196                 if (prompt) {
 197                         printf("%s", prompt);
 198                         fflush(stdout);
 199                 }
 200                 if ((n = get_tty_line()) < 0) {
 201                         status = ERR;
 202                         continue;
 203                 } else if (n == 0) {
 204                         if (modified && !scripted) {
 205                                 fputs("?\n", stderr);
 206                                 seterrmsg("warning: file modified");
 207                                 if (!isatty(0)) {
 208                                         if (garrulous) {
 209                                                 fprintf(stderr,
 210                                                     "script, line %d: %s\n",
 211                                                     lineno, errmsg);
 212                                         }
 213                                         quit(2);
 214                                 }
 215                                 clearerr(stdin);
 216                                 modified = 0;
 217                                 status = EMOD;
 218                                 continue;
 219                         } else
 220                                 quit(0);
 221                 } else if (ibuf[n - 1] != '\n') {
 222                         /* discard line */
 223                         seterrmsg("unexpected end-of-file");
 224                         clearerr(stdin);
 225                         status = ERR;
 226                         continue;
 227                 }
 228                 isglobal = 0;
 229                 if ((status = extract_addr_range()) >= 0 &&
 230                     (status = exec_command()) >= 0) {
 231                         if (status == 0)
 232                                 continue;
 233                         status = display_lines(current_addr, current_addr,
 234                             status);
 235                         if (status >= 0)
 236                                 continue;
 237                 }
 238                 switch (status) {
 239                 case EOF:
 240                         quit(0);
 241                 case EMOD:
 242                         modified = 0;
 243                         fputs("?\n", stderr);           /* give warning */
 244                         seterrmsg("warning: file modified");
 245                         if (!isatty(0)) {
 246                                 if (garrulous) {
 247                                         fprintf(stderr,
 248                                             "script, line %d: %s\n",
 249                                             lineno, errmsg);
 250                                 }
 251                                 quit(2);
 252                         }
 253                         break;
 254                 case FATAL:
 255                         if (garrulous) {
 256                                 if (!isatty(0)) {
 257                                         fprintf(stderr,
 258                                             "script, line %d: %s\n",
 259                                             lineno, errmsg);
 260                                 } else {
 261                                         fprintf(stderr, "%s\n", errmsg);
 262                                 }
 263                         }
 264                         quit(3);
 265                 default:
 266                         fputs("?\n", stderr);
 267                         if (!isatty(0)) {
 268                                 if (garrulous) {
 269                                         fprintf(stderr, "script, line %d: %s\n",
 270                                             lineno, errmsg);
 271                                 }
 272                                 quit(2);
 273                         }
 274                         break;
 275                 }
 276         }
 277         /* NOTREACHED */
 278 }
 279
 280 long first_addr, second_addr, addr_cnt;
 281
 282 /* extract_addr_range: get line addresses from the command buffer until an
 283    illegal address is seen; return status */
 284 int
 285 extract_addr_range(void)
 286 {
 287         long addr;
 288
 289         addr_cnt = 0;
 290         first_addr = second_addr = current_addr;
 291         while ((addr = next_addr()) >= 0) {
 292                 addr_cnt++;
 293                 first_addr = second_addr;
 294                 second_addr = addr;
 295                 if (*ibufp != ',' && *ibufp != ';')
 296                         break;
 297                 else if (*ibufp++ == ';')
 298                         current_addr = addr;
 299         }
 300         if ((addr_cnt = min(addr_cnt, 2)) == 1 || second_addr != addr)
 301                 first_addr = second_addr;
 302         return (addr == ERR) ? ERR : 0;
 303 }
 304
 305
 306 #define SKIP_BLANKS() while (isspace((unsigned char)*ibufp) && *ibufp != '\n') \
 307         ibufp++
 308
 309 #define MUST_BE_FIRST() \
 310         if (!first) { seterrmsg("invalid address"); return ERR; }
 311
 312 /*  next_addr: return the next line address in the command buffer */
 313 long
 314 next_addr(void)
 315 {
 316         char *hd;
 317         long addr = current_addr;
 318         long n;
 319         int first = 1;
 320         int c;
 321
 322         SKIP_BLANKS();
 323         for (hd = ibufp;; first = 0)
 324                 switch (c = *ibufp) {
 325                 case '+':
 326                 case '\t':
 327                 case ' ':
 328                 case '-':
 329                 case '^':
 330                         ibufp++;
 331                         SKIP_BLANKS();
 332                         if (isdigit((unsigned char)*ibufp)) {
 333                                 STRTOL(n, ibufp);
 334                                 addr += (c == '-' || c == '^') ? -n : n;
 335                         } else if (!isspace((unsigned char)c))
 336                                 addr += (c == '-' || c == '^') ? -1 : 1;
 337                         break;
 338                 case '0': case '1': case '2':
 339                 case '3': case '4': case '5':
 340                 case '6': case '7': case '8': case '9':
 341                         MUST_BE_FIRST();
 342                         STRTOL(addr, ibufp);
 343                         break;
 344                 case '.':
 345                 case '$':
 346                         MUST_BE_FIRST();
 347                         ibufp++;
 348                         addr = (c == '.') ? current_addr : addr_last;
 349                         break;
 350                 case '/':
 351                 case '?':
 352                         MUST_BE_FIRST();
 353                         if ((addr = get_matching_node_addr(
 354                             get_compiled_pattern(), c == '/')) < 0)
 355                                 return ERR;
 356                         else if (c == *ibufp)
 357                                 ibufp++;
 358                         break;
 359                 case '\'':
 360                         MUST_BE_FIRST();
 361                         ibufp++;
 362                         if ((addr = get_marked_node_addr((unsigned char)*ibufp++)) < 0)
 363                                 return ERR;
 364                         break;
 365                 case '%':
 366                 case ',':
 367                 case ';':
 368                         if (first) {
 369                                 ibufp++;
 370                                 addr_cnt++;
 371                                 second_addr = (c == ';') ? current_addr : 1;
 372                                 addr = addr_last;
 373                                 break;
 374                         }
 375                         /* FALL THROUGH */
 376                 default:
 377                         if (ibufp == hd)
 378                                 return EOF;
 379                         else if (addr < 0 || addr_last < addr) {
 380                                 seterrmsg("invalid address");
 381                                 return ERR;
 382                         } else
 383                                 return addr;
 384                 }
 385         /* NOTREACHED */
 386 }
 387
 388
 389 #ifdef BACKWARDS
 390 /* GET_THIRD_ADDR: get a legal address from the command buffer */
 391 #define GET_THIRD_ADDR(addr) \
 392 { \
 393         long ol1, ol2; \
 394 \
 395         ol1 = first_addr, ol2 = second_addr; \
 396         if (extract_addr_range() < 0) \
 397                 return ERR; \
 398         else if (addr_cnt == 0) { \
 399                 seterrmsg("destination expected"); \
 400                 return ERR; \
 401         } else if (second_addr < 0 || addr_last < second_addr) { \
 402                 seterrmsg("invalid address"); \
 403                 return ERR; \
 404         } \
 405         addr = second_addr; \
 406         first_addr = ol1, second_addr = ol2; \
 407 }
 408 #else   /* BACKWARDS */
 409 /* GET_THIRD_ADDR: get a legal address from the command buffer */
 410 #define GET_THIRD_ADDR(addr) \
 411 { \
 412         long ol1, ol2; \
 413 \
 414         ol1 = first_addr, ol2 = second_addr; \
 415         if (extract_addr_range() < 0) \
 416                 return ERR; \
 417         if (second_addr < 0 || addr_last < second_addr) { \
 418                 seterrmsg("invalid address"); \
 419                 return ERR; \
 420         } \
 421         addr = second_addr; \
 422         first_addr = ol1, second_addr = ol2; \
 423 }
 424 #endif
 425
 426
 427 /* GET_COMMAND_SUFFIX: verify the command suffix in the command buffer */
 428 #define GET_COMMAND_SUFFIX() { \
 429         int done = 0; \
 430         do { \
 431                 switch(*ibufp) { \
 432                 case 'p': \
 433                         gflag |= GPR, ibufp++; \
 434                         break; \
 435                 case 'l': \
 436                         gflag |= GLS, ibufp++; \
 437                         break; \
 438                 case 'n': \
 439                         gflag |= GNP, ibufp++; \
 440                         break; \
 441                 default: \
 442                         done++; \
 443                 } \
 444         } while (!done); \
 445         if (*ibufp++ != '\n') { \
 446                 seterrmsg("invalid command suffix"); \
 447                 return ERR; \
 448         } \
 449 }
 450
 451
 452 /* sflags */
 453 #define SGG 001         /* complement previous global substitute suffix */
 454 #define SGP 002         /* complement previous print suffix */
 455 #define SGR 004         /* use last regex instead of last pat */
 456 #define SGF 010         /* repeat last substitution */
 457
 458 int patlock = 0;        /* if set, pattern not freed by get_compiled_pattern() */
 459
 460 long rows = 22;         /* scroll length: ws_row - 2 */
 461
 462 /* exec_command: execute the next command in command buffer; return print
 463    request, if any */
 464 int
 465 exec_command(void)
 466 {
 467         static pattern_t *pat = NULL;
 468         static int sgflag = 0;
 469         static long sgnum = 0;
 470
 471         pattern_t *tpat;
 472         char *fnp;
 473         int gflag = 0;
 474         int sflags = 0;
 475         long addr = 0;
 476         int n = 0;
 477         int c;
 478
 479         SKIP_BLANKS();
 480         switch(c = *ibufp++) {
 481         case 'a':
 482                 GET_COMMAND_SUFFIX();
 483                 if (!isglobal) clear_undo_stack();
 484                 if (append_lines(second_addr) < 0)
 485                         return ERR;
 486                 break;
 487         case 'c':
 488                 if (check_addr_range(current_addr, current_addr) < 0)
 489                         return ERR;
 490                 GET_COMMAND_SUFFIX();
 491                 if (!isglobal) clear_undo_stack();
 492                 if (delete_lines(first_addr, second_addr) < 0 ||
 493                     append_lines(current_addr) < 0)
 494                         return ERR;
 495                 break;
 496         case 'd':
 497                 if (check_addr_range(current_addr, current_addr) < 0)
 498                         return ERR;
 499                 GET_COMMAND_SUFFIX();
 500                 if (!isglobal) clear_undo_stack();
 501                 if (delete_lines(first_addr, second_addr) < 0)
 502                         return ERR;
 503                 else if ((addr = INC_MOD(current_addr, addr_last)) != 0)
 504                         current_addr = addr;
 505                 break;
 506         case 'e':
 507                 if (modified && !scripted)
 508                         return EMOD;
 509                 /* fall through */
 510         case 'E':
 511                 if (addr_cnt > 0) {
 512                         seterrmsg("unexpected address");
 513                         return ERR;
 514                 } else if (!isspace((unsigned char)*ibufp)) {
 515                         seterrmsg("unexpected command suffix");
 516                         return ERR;
 517                 } else if ((fnp = get_filename()) == NULL)
 518                         return ERR;
 519                 GET_COMMAND_SUFFIX();
 520                 if (delete_lines(1, addr_last) < 0)
 521                         return ERR;
 522                 clear_undo_stack();
 523                 if (close_sbuf() < 0)
 524                         return ERR;
 525                 else if (open_sbuf() < 0)
 526                         return FATAL;
 527                 if (*fnp && *fnp != '!') strlcpy(old_filename, fnp,
 528                         sizeof(old_filename) - 2);
 529 #ifdef BACKWARDS
 530                 if (*fnp == '\0' && *old_filename == '\0') {
 531                         seterrmsg("no current filename");
 532                         return ERR;
 533                 }
 534 #endif
 535                 if (read_file(*fnp ? fnp : old_filename, 0) < 0)
 536                         return ERR;
 537                 clear_undo_stack();
 538                 modified = 0;
 539                 u_current_addr = u_addr_last = -1;
 540                 break;
 541         case 'f':
 542                 if (addr_cnt > 0) {
 543                         seterrmsg("unexpected address");
 544                         return ERR;
 545                 } else if (!isspace((unsigned char)*ibufp)) {
 546                         seterrmsg("unexpected command suffix");
 547                         return ERR;
 548                 } else if ((fnp = get_filename()) == NULL)
 549                         return ERR;
 550                 else if (*fnp == '!') {
 551                         seterrmsg("invalid redirection");
 552                         return ERR;
 553                 }
 554                 GET_COMMAND_SUFFIX();
 555                 if (*fnp) strlcpy(old_filename, fnp, sizeof(old_filename) - 2);
 556                 printf("%s\n", strip_escapes(old_filename));
 557                 break;
 558         case 'g':
 559         case 'v':
 560         case 'G':
 561         case 'V':
 562                 if (isglobal) {
 563                         seterrmsg("cannot nest global commands");
 564                         return ERR;
 565                 } else if (check_addr_range(1, addr_last) < 0)
 566                         return ERR;
 567                 else if (build_active_list(c == 'g' || c == 'G') < 0)
 568                         return ERR;
 569                 else if ((n = (c == 'G' || c == 'V')) != 0)
 570                         GET_COMMAND_SUFFIX();
 571                 isglobal++;
 572                 if (exec_global(n, gflag) < 0)
 573                         return ERR;
 574                 break;
 575         case 'h':
 576                 if (addr_cnt > 0) {
 577                         seterrmsg("unexpected address");
 578                         return ERR;
 579                 }
 580                 GET_COMMAND_SUFFIX();
 581                 if (*errmsg) fprintf(stderr, "%s\n", errmsg);
 582                 break;
 583         case 'H':
 584                 if (addr_cnt > 0) {
 585                         seterrmsg("unexpected address");
 586                         return ERR;
 587                 }
 588                 GET_COMMAND_SUFFIX();
 589                 if ((garrulous = 1 - garrulous) && *errmsg)
 590                         fprintf(stderr, "%s\n", errmsg);
 591                 break;
 592         case 'i':
 593                 if (second_addr == 0) {
 594                         seterrmsg("invalid address");
 595                         return ERR;
 596                 }
 597                 GET_COMMAND_SUFFIX();
 598                 if (!isglobal) clear_undo_stack();
 599                 if (append_lines(second_addr - 1) < 0)
 600                         return ERR;
 601                 break;
 602         case 'j':
 603                 if (check_addr_range(current_addr, current_addr + 1) < 0)
 604                         return ERR;
 605                 GET_COMMAND_SUFFIX();
 606                 if (!isglobal) clear_undo_stack();
 607                 if (first_addr != second_addr &&
 608                     join_lines(first_addr, second_addr) < 0)
 609                         return ERR;
 610                 break;
 611         case 'k':
 612                 c = *ibufp++;
 613                 if (second_addr == 0) {
 614                         seterrmsg("invalid address");
 615                         return ERR;
 616                 }
 617                 GET_COMMAND_SUFFIX();
 618                 if (mark_line_node(get_addressed_line_node(second_addr), (unsigned char)c) < 0)
 619                         return ERR;
 620                 break;
 621         case 'l':
 622                 if (check_addr_range(current_addr, current_addr) < 0)
 623                         return ERR;
 624                 GET_COMMAND_SUFFIX();
 625                 if (display_lines(first_addr, second_addr, gflag | GLS) < 0)
 626                         return ERR;
 627                 gflag = 0;
 628                 break;
 629         case 'm':
 630                 if (check_addr_range(current_addr, current_addr) < 0)
 631                         return ERR;
 632                 GET_THIRD_ADDR(addr);
 633                 if (first_addr <= addr && addr < second_addr) {
 634                         seterrmsg("invalid destination");
 635                         return ERR;
 636                 }
 637                 GET_COMMAND_SUFFIX();
 638                 if (!isglobal) clear_undo_stack();
 639                 if (move_lines(addr) < 0)
 640                         return ERR;
 641                 break;
 642         case 'n':
 643                 if (check_addr_range(current_addr, current_addr) < 0)
 644                         return ERR;
 645                 GET_COMMAND_SUFFIX();
 646                 if (display_lines(first_addr, second_addr, gflag | GNP) < 0)
 647                         return ERR;
 648                 gflag = 0;
 649                 break;
 650         case 'p':
 651                 if (check_addr_range(current_addr, current_addr) < 0)
 652                         return ERR;
 653                 GET_COMMAND_SUFFIX();
 654                 if (display_lines(first_addr, second_addr, gflag | GPR) < 0)
 655                         return ERR;
 656                 gflag = 0;
 657                 break;
 658         case 'P':
 659                 if (addr_cnt > 0) {
 660                         seterrmsg("unexpected address");
 661                         return ERR;
 662                 }
 663                 GET_COMMAND_SUFFIX();
 664                 prompt = prompt ? NULL : optarg ? optarg : dps;
 665                 break;
 666         case 'q':
 667         case 'Q':
 668                 if (addr_cnt > 0) {
 669                         seterrmsg("unexpected address");
 670                         return ERR;
 671                 }
 672                 GET_COMMAND_SUFFIX();
 673                 gflag =  (modified && !scripted && c == 'q') ? EMOD : EOF;
 674                 break;
 675         case 'r':
 676                 if (!isspace((unsigned char)*ibufp)) {
 677                         seterrmsg("unexpected command suffix");
 678                         return ERR;
 679                 } else if (addr_cnt == 0)
 680                         second_addr = addr_last;
 681                 if ((fnp = get_filename()) == NULL)
 682                         return ERR;
 683                 GET_COMMAND_SUFFIX();
 684                 if (!isglobal) clear_undo_stack();
 685                 if (*old_filename == '\0' && *fnp != '!')
 686                         strlcpy(old_filename, fnp, sizeof(old_filename) - 2);
 687 #ifdef BACKWARDS
 688                 if (*fnp == '\0' && *old_filename == '\0') {
 689                         seterrmsg("no current filename");
 690                         return ERR;
 691                 }
 692 #endif
 693                 if ((addr = read_file(*fnp ? fnp : old_filename, second_addr)) < 0)
 694                         return ERR;
 695                 else if (addr && addr != addr_last)
 696                         modified = 1;
 697                 break;
 698         case 's':
 699                 do {
 700                         switch(*ibufp) {
 701                         case '\n':
 702                                 sflags |=SGF;
 703                                 break;
 704                         case 'g':
 705                                 sflags |= SGG;
 706                                 ibufp++;
 707                                 break;
 708                         case 'p':
 709                                 sflags |= SGP;
 710                                 ibufp++;
 711                                 break;
 712                         case 'r':
 713                                 sflags |= SGR;
 714                                 ibufp++;
 715                                 break;
 716                         case '0': case '1': case '2': case '3': case '4':
 717                         case '5': case '6': case '7': case '8': case '9':
 718                                 STRTOL(sgnum, ibufp);
 719                                 sflags |= SGF;
 720                                 sgflag &= ~GSG;         /* override GSG */
 721                                 break;
 722                         default:
 723                                 if (sflags) {
 724                                         seterrmsg("invalid command suffix");
 725                                         return ERR;
 726                                 }
 727                         }
 728                 } while (sflags && *ibufp != '\n');
 729                 if (sflags && !pat) {
 730                         seterrmsg("no previous substitution");
 731                         return ERR;
 732                 } else if (sflags & SGG)
 733                         sgnum = 0;              /* override numeric arg */
 734                 if (*ibufp != '\n' && *(ibufp + 1) == '\n') {
 735                         seterrmsg("invalid pattern delimiter");
 736                         return ERR;
 737                 }
 738                 tpat = pat;
 739                 SPL1();
 740                 if ((!sflags || (sflags & SGR)) &&
 741                     (tpat = get_compiled_pattern()) == NULL) {
 742                         SPL0();
 743                         return ERR;
 744                 } else if (tpat != pat) {
 745                         if (pat) {
 746                                 regfree(pat);
 747                                 free(pat);
 748                         }
 749                         pat = tpat;
 750                         patlock = 1;            /* reserve pattern */
 751                 }
 752                 SPL0();
 753                 if (!sflags && extract_subst_tail(&sgflag, &sgnum) < 0)
 754                         return ERR;
 755                 else if (isglobal)
 756                         sgflag |= GLB;
 757                 else
 758                         sgflag &= ~GLB;
 759                 if (sflags & SGG)
 760                         sgflag ^= GSG;
 761                 if (sflags & SGP)
 762                         sgflag ^= GPR, sgflag &= ~(GLS | GNP);
 763                 do {
 764                         switch(*ibufp) {
 765                         case 'p':
 766                                 sgflag |= GPR, ibufp++;
 767                                 break;
 768                         case 'l':
 769                                 sgflag |= GLS, ibufp++;
 770                                 break;
 771                         case 'n':
 772                                 sgflag |= GNP, ibufp++;
 773                                 break;
 774                         default:
 775                                 n++;
 776                         }
 777                 } while (!n);
 778                 if (check_addr_range(current_addr, current_addr) < 0)
 779                         return ERR;
 780                 GET_COMMAND_SUFFIX();
 781                 if (!isglobal) clear_undo_stack();
 782                 if (search_and_replace(pat, sgflag, sgnum) < 0)
 783                         return ERR;
 784                 break;
 785         case 't':
 786                 if (check_addr_range(current_addr, current_addr) < 0)
 787                         return ERR;
 788                 GET_THIRD_ADDR(addr);
 789                 GET_COMMAND_SUFFIX();
 790                 if (!isglobal) clear_undo_stack();
 791                 if (copy_lines(addr) < 0)
 792                         return ERR;
 793                 break;
 794         case 'u':
 795                 if (addr_cnt > 0) {
 796                         seterrmsg("unexpected address");
 797                         return ERR;
 798                 }
 799                 GET_COMMAND_SUFFIX();
 800                 if (pop_undo_stack() < 0)
 801                         return ERR;
 802                 break;
 803         case 'w':
 804         case 'W':
 805                 if ((n = *ibufp) == 'q' || n == 'Q') {
 806                         gflag = EOF;
 807                         ibufp++;
 808                 }
 809                 if (!isspace((unsigned char)*ibufp)) {
 810                         seterrmsg("unexpected command suffix");
 811                         return ERR;
 812                 } else if ((fnp = get_filename()) == NULL)
 813                         return ERR;
 814                 if (addr_cnt == 0 && !addr_last)
 815                         first_addr = second_addr = 0;
 816                 else if (check_addr_range(1, addr_last) < 0)
 817                         return ERR;
 818                 GET_COMMAND_SUFFIX();
 819                 if (*old_filename == '\0' && *fnp != '!')
 820                         strlcpy(old_filename, fnp, sizeof(old_filename) - 2);
 821 #ifdef BACKWARDS
 822                 if (*fnp == '\0' && *old_filename == '\0') {
 823                         seterrmsg("no current filename");
 824                         return ERR;
 825                 }
 826 #endif
 827                 if ((addr = write_file(*fnp ? fnp : old_filename,
 828                     (c == 'W') ? "a" : "w", first_addr, second_addr)) < 0)
 829                         return ERR;
 830                 else if (addr == addr_last)
 831                         modified = 0;
 832                 else if (modified && !scripted && n == 'q')
 833                         gflag = EMOD;
 834                 break;
 835         case 'x':
 836                 if (addr_cnt > 0) {
 837                         seterrmsg("unexpected address");
 838                         return ERR;
 839                 }
 840                 GET_COMMAND_SUFFIX();
 841 #ifdef DES
 842                 des = get_keyword();
 843 #else
 844                 seterrmsg("crypt unavailable");
 845                 return ERR;
 846 #endif
 847                 break;
 848         case 'z':
 849 #ifdef BACKWARDS
 850                 if (check_addr_range(first_addr = 1, current_addr + 1) < 0)
 851 #else
 852                 if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0)
 853 #endif
 854                         return ERR;
 855                 else if ('0' < *ibufp && *ibufp <= '9')
 856                         STRTOL(rows, ibufp);
 857                 GET_COMMAND_SUFFIX();
 858                 if (display_lines(second_addr, min(addr_last,
 859                     second_addr + rows), gflag) < 0)
 860                         return ERR;
 861                 gflag = 0;
 862                 break;
 863         case '=':
 864                 GET_COMMAND_SUFFIX();
 865                 printf("%ld\n", addr_cnt ? second_addr : addr_last);
 866                 break;
 867         case '!':
 868                 if (addr_cnt > 0) {
 869                         seterrmsg("unexpected address");
 870                         return ERR;
 871                 }
 872                 if ((sflags = get_shell_command()) < 0)
 873                         return ERR;
 874                 GET_COMMAND_SUFFIX();
 875                 if (sflags) printf("%s\n", shcmd + 1);
 876                 system(shcmd + 1);
 877                 if (!scripted) printf("!\n");
 878                 break;
 879         case '\n':
 880 #ifdef BACKWARDS
 881                 if (check_addr_range(first_addr = 1, current_addr + 1) < 0
 882 #else
 883                 if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0
 884 #endif
 885                  || display_lines(second_addr, second_addr, 0) < 0)
 886                         return ERR;
 887                 break;
 888         default:
 889                 seterrmsg("unknown command");
 890                 return ERR;
 891         }
 892         return gflag;
 893 }
 894
 895
 896 /* check_addr_range: return status of address range check */
 897 int
 898 check_addr_range(long n, long m)
 899 {
 900         if (addr_cnt == 0) {
 901                 first_addr = n;
 902                 second_addr = m;
 903         }
 904         if (first_addr > second_addr || 1 > first_addr ||
 905             second_addr > addr_last) {
 906                 seterrmsg("invalid address");
 907                 return ERR;
 908         }
 909         return 0;
 910 }
 911
 912
 913 /* get_matching_node_addr: return the address of the next line matching a
 914    pattern in a given direction.  wrap around begin/end of editor buffer if
 915    necessary */
 916 long
 917 get_matching_node_addr(pattern_t *pat, int dir)
 918 {
 919         char *s;
 920         long n = current_addr;
 921         line_t *lp;
 922
 923         if (!pat) return ERR;
 924         do {
 925                 if ((n = dir ? INC_MOD(n, addr_last) :
 926                     DEC_MOD(n, addr_last)) != 0) {
 927                         lp = get_addressed_line_node(n);
 928                         if ((s = get_sbuf_line(lp)) == NULL)
 929                                 return ERR;
 930                         if (isbinary)
 931                                 NUL_TO_NEWLINE(s, lp->len);
 932                         if (!regexec(pat, s, 0, NULL, 0))
 933                                 return n;
 934                 }
 935         } while (n != current_addr);
 936         seterrmsg("no match");
 937         return  ERR;
 938 }
 939
 940
 941 /* get_filename: return pointer to copy of filename in the command buffer */
 942 char *
 943 get_filename(void)
 944 {
 945         static char *file = NULL;
 946         static int filesz = 0;
 947
 948         int n;
 949
 950         if (*ibufp != '\n') {
 951                 SKIP_BLANKS();
 952                 if (*ibufp == '\n') {
 953                         seterrmsg("invalid filename");
 954                         return NULL;
 955                 } else if ((ibufp = get_extended_line(&n, 1)) == NULL)
 956                         return NULL;
 957                 else if (*ibufp == '!') {
 958                         ibufp++;
 959                         if ((n = get_shell_command()) < 0)
 960                                 return NULL;
 961                         if (n) printf("%s\n", shcmd + 1);
 962                         return shcmd;
 963                 } else if (n - 1 > MAXPATHLEN) {
 964                         seterrmsg("filename too long");
 965                         return  NULL;
 966                 }
 967         }
 968 #ifndef BACKWARDS
 969         else if (*old_filename == '\0') {
 970                 seterrmsg("no current filename");
 971                 return  NULL;
 972         }
 973 #endif
 974         REALLOC(file, filesz, MAXPATHLEN + 1, NULL);
 975         for (n = 0; *ibufp != '\n';)
 976                 file[n++] = *ibufp++;
 977         file[n] = '\0';
 978         return is_legal_filename(file) ? file : NULL;
 979 }
 980
 981
 982 /* get_shell_command: read a shell command from stdin; return substitution
 983    status */
 984 int
 985 get_shell_command(void)
 986 {
 987         static char *buf = NULL;
 988         static int n = 0;
 989
 990         char *s;                        /* substitution char pointer */
 991         int i = 0;
 992         int j = 0;
 993
 994         if (red || secure) {
 995                 seterrmsg("shell access restricted");
 996                 return ERR;
 997         } else if ((s = ibufp = get_extended_line(&j, 1)) == NULL)
 998                 return ERR;
 999         REALLOC(buf, n, j + 1, ERR);
1000         buf[i++] = '!';                 /* prefix command w/ bang */
1001         while (*ibufp != '\n')
1002                 switch (*ibufp) {
1003                 default:
1004                         REALLOC(buf, n, i + 2, ERR);
1005                         buf[i++] = *ibufp;
1006                         if (*ibufp++ == '\\')
1007                                 buf[i++] = *ibufp++;
1008                         break;
1009                 case '!':
1010                         if (s != ibufp) {
1011                                 REALLOC(buf, n, i + 1, ERR);
1012                                 buf[i++] = *ibufp++;
1013                         }
1014 #ifdef BACKWARDS
1015                         else if (shcmd == NULL || *(shcmd + 1) == '\0')
1016 #else
1017                         else if (shcmd == NULL)
1018 #endif
1019                         {
1020                                 seterrmsg("no previous command");
1021                                 return ERR;
1022                         } else {
1023                                 REALLOC(buf, n, i + shcmdi, ERR);
1024                                 for (s = shcmd + 1; s < shcmd + shcmdi;)
1025                                         buf[i++] = *s++;
1026                                 s = ibufp++;
1027                         }
1028                         break;
1029                 case '%':
1030                         if (*old_filename  == '\0') {
1031                                 seterrmsg("no current filename");
1032                                 return ERR;
1033                         }
1034                         j = strlen(s = strip_escapes(old_filename));
1035                         REALLOC(buf, n, i + j, ERR);
1036                         while (j--)
1037                                 buf[i++] = *s++;
1038                         s = ibufp++;
1039                         break;
1040                 }
1041         REALLOC(shcmd, shcmdsz, i + 1, ERR);
1042         memcpy(shcmd, buf, i);
1043         shcmd[shcmdi = i] = '\0';
1044         return *s == '!' || *s == '%';
1045 }
1046
1047
1048 /* append_lines: insert text from stdin to after line n; stop when either a
1049    single period is read or EOF; return status */
1050 int
1051 append_lines(long n)
1052 {
1053         int l;
1054         char *lp = ibuf;
1055         char *eot;
1056         undo_t *up = NULL;
1057
1058         for (current_addr = n;;) {
1059                 if (!isglobal) {
1060                         if ((l = get_tty_line()) < 0)
1061                                 return ERR;
1062                         else if (l == 0 || ibuf[l - 1] != '\n') {
1063                                 clearerr(stdin);
1064                                 return  l ? EOF : 0;
1065                         }
1066                         lp = ibuf;
1067                 } else if (*(lp = ibufp) == '\0')
1068                         return 0;
1069                 else {
1070                         while (*ibufp++ != '\n')
1071                                 ;
1072                         l = ibufp - lp;
1073                 }
1074                 if (l == 2 && lp[0] == '.' && lp[1] == '\n') {
1075                         return 0;
1076                 }
1077                 eot = lp + l;
1078                 SPL1();
1079                 do {
1080                         if ((lp = put_sbuf_line(lp)) == NULL) {
1081                                 SPL0();
1082                                 return ERR;
1083                         } else if (up)
1084                                 up->t = get_addressed_line_node(current_addr);
1085                         else if ((up = push_undo_stack(UADD, current_addr,
1086                             current_addr)) == NULL) {
1087                                 SPL0();
1088                                 return ERR;
1089                         }
1090                 } while (lp != eot);
1091                 modified = 1;
1092                 SPL0();
1093         }
1094         /* NOTREACHED */
1095 }
1096
1097
1098 /* join_lines: replace a range of lines with the joined text of those lines */
1099 int
1100 join_lines(long from, long to)
1101 {
1102         static char *buf = NULL;
1103         static int n;
1104
1105         char *s;
1106         int size = 0;
1107         line_t *bp, *ep;
1108
1109         ep = get_addressed_line_node(INC_MOD(to, addr_last));
1110         bp = get_addressed_line_node(from);
1111         for (; bp != ep; bp = bp->q_forw) {
1112                 if ((s = get_sbuf_line(bp)) == NULL)
1113                         return ERR;
1114                 REALLOC(buf, n, size + bp->len, ERR);
1115                 memcpy(buf + size, s, bp->len);
1116                 size += bp->len;
1117         }
1118         REALLOC(buf, n, size + 2, ERR);
1119         memcpy(buf + size, "\n", 2);
1120         if (delete_lines(from, to) < 0)
1121                 return ERR;
1122         current_addr = from - 1;
1123         SPL1();
1124         if (put_sbuf_line(buf) == NULL ||
1125             push_undo_stack(UADD, current_addr, current_addr) == NULL) {
1126                 SPL0();
1127                 return ERR;
1128         }
1129         modified = 1;
1130         SPL0();
1131         return 0;
1132 }
1133
1134
1135 /* move_lines: move a range of lines */
1136 int
1137 move_lines(long addr)
1138 {
1139         line_t *b1, *a1, *b2, *a2;
1140         long n = INC_MOD(second_addr, addr_last);
1141         long p = first_addr - 1;
1142         int done = (addr == first_addr - 1 || addr == second_addr);
1143
1144         SPL1();
1145         if (done) {
1146                 a2 = get_addressed_line_node(n);
1147                 b2 = get_addressed_line_node(p);
1148                 current_addr = second_addr;
1149         } else if (push_undo_stack(UMOV, p, n) == NULL ||
1150             push_undo_stack(UMOV, addr, INC_MOD(addr, addr_last)) == NULL) {
1151                 SPL0();
1152                 return ERR;
1153         } else {
1154                 a1 = get_addressed_line_node(n);
1155                 if (addr < first_addr) {
1156                         b1 = get_addressed_line_node(p);
1157                         b2 = get_addressed_line_node(addr);
1158                                         /* this get_addressed_line_node last! */
1159                 } else {
1160                         b2 = get_addressed_line_node(addr);
1161                         b1 = get_addressed_line_node(p);
1162                                         /* this get_addressed_line_node last! */
1163                 }
1164                 a2 = b2->q_forw;
1165                 REQUE(b2, b1->q_forw);
1166                 REQUE(a1->q_back, a2);
1167                 REQUE(b1, a1);
1168                 current_addr = addr + ((addr < first_addr) ?
1169                     second_addr - first_addr + 1 : 0);
1170         }
1171         if (isglobal)
1172                 unset_active_nodes(b2->q_forw, a2);
1173         modified = 1;
1174         SPL0();
1175         return 0;
1176 }
1177
1178
1179 /* copy_lines: copy a range of lines; return status */
1180 int
1181 copy_lines(long addr)
1182 {
1183         line_t *lp, *np = get_addressed_line_node(first_addr);
1184         undo_t *up = NULL;
1185         long n = second_addr - first_addr + 1;
1186         long m = 0;
1187
1188         current_addr = addr;
1189         if (first_addr <= addr && addr < second_addr) {
1190                 n =  addr - first_addr + 1;
1191                 m = second_addr - addr;
1192         }
1193         for (; n > 0; n=m, m=0, np = get_addressed_line_node(current_addr + 1))
1194                 for (; n-- > 0; np = np->q_forw) {
1195                         SPL1();
1196                         if ((lp = dup_line_node(np)) == NULL) {
1197                                 SPL0();
1198                                 return ERR;
1199                         }
1200                         add_line_node(lp);
1201                         if (up)
1202                                 up->t = lp;
1203                         else if ((up = push_undo_stack(UADD, current_addr,
1204                             current_addr)) == NULL) {
1205                                 SPL0();
1206                                 return ERR;
1207                         }
1208                         modified = 1;
1209                         SPL0();
1210                 }
1211         return 0;
1212 }
1213
1214
1215 /* delete_lines: delete a range of lines */
1216 int
1217 delete_lines(long from, long to)
1218 {
1219         line_t *n, *p;
1220
1221         SPL1();
1222         if (push_undo_stack(UDEL, from, to) == NULL) {
1223                 SPL0();
1224                 return ERR;
1225         }
1226         n = get_addressed_line_node(INC_MOD(to, addr_last));
1227         p = get_addressed_line_node(from - 1);
1228                                         /* this get_addressed_line_node last! */
1229         if (isglobal)
1230                 unset_active_nodes(p->q_forw, n);
1231         REQUE(p, n);
1232         addr_last -= to - from + 1;
1233         current_addr = from - 1;
1234         modified = 1;
1235         SPL0();
1236         return 0;
1237 }
1238
1239
1240 /* display_lines: print a range of lines to stdout */
1241 int
1242 display_lines(long from, long to, int gflag)
1243 {
1244         line_t *bp;
1245         line_t *ep;
1246         char *s;
1247
1248         if (!from) {
1249                 seterrmsg("invalid address");
1250                 return ERR;
1251         }
1252         ep = get_addressed_line_node(INC_MOD(to, addr_last));
1253         bp = get_addressed_line_node(from);
1254         for (; bp != ep; bp = bp->q_forw) {
1255                 if ((s = get_sbuf_line(bp)) == NULL)
1256                         return ERR;
1257                 if (put_tty_line(s, bp->len, current_addr = from++, gflag) < 0)
1258                         return ERR;
1259         }
1260         return 0;
1261 }
1262
1263
1264 #define MAXMARK 26                      /* max number of marks */
1265
1266 line_t  *mark[MAXMARK];                 /* line markers */
1267 int markno;                             /* line marker count */
1268
1269 /* mark_line_node: set a line node mark */
1270 int
1271 mark_line_node(line_t *lp, int n)
1272 {
1273         if (!islower(n)) {
1274                 seterrmsg("invalid mark character");
1275                 return ERR;
1276         } else if (mark[n - 'a'] == NULL)
1277                 markno++;
1278         mark[n - 'a'] = lp;
1279         return 0;
1280 }
1281
1282
1283 /* get_marked_node_addr: return address of a marked line */
1284 long
1285 get_marked_node_addr(int n)
1286 {
1287         if (!islower(n)) {
1288                 seterrmsg("invalid mark character");
1289                 return ERR;
1290         }
1291         return get_line_node_addr(mark[n - 'a']);
1292 }
1293
1294
1295 /* unmark_line_node: clear line node mark */
1296 void
1297 unmark_line_node(line_t *lp)
1298 {
1299         int i;
1300
1301         for (i = 0; markno && i < MAXMARK; i++)
1302                 if (mark[i] == lp) {
1303                         mark[i] = NULL;
1304                         markno--;
1305                 }
1306 }
1307
1308
1309 /* dup_line_node: return a pointer to a copy of a line node */
1310 line_t *
1311 dup_line_node(line_t *lp)
1312 {
1313         line_t *np;
1314
1315         if ((np = (line_t *) malloc(sizeof(line_t))) == NULL) {
1316                 fprintf(stderr, "%s\n", strerror(errno));
1317                 seterrmsg("out of memory");
1318                 return NULL;
1319         }
1320         np->seek = lp->seek;
1321         np->len = lp->len;
1322         return np;
1323 }
1324
1325
1326 /* has_trailing_escape:  return the parity of escapes preceding a character
1327    in a string */
1328 int
1329 has_trailing_escape(char *s, char *t)
1330 {
1331     return (s == t || *(t - 1) != '\\') ? 0 : !has_trailing_escape(s, t - 1);
1332 }
1333
1334
1335 /* strip_escapes: return copy of escaped string of at most length MAXPATHLEN */
1336 char *
1337 strip_escapes(const char *s)
1338 {
1339         static char *file = NULL;
1340         static int filesz = 0;
1341
1342         int i = 0;
1343
1344         REALLOC(file, filesz, MAXPATHLEN + 1, NULL);
1345         while ((i < (filesz - 1)) &&
1346                (file[i++] = (*s == '\\') != '\0' ? *++s : *s))
1347                 s++;
1348         file[filesz - 1] = '\0';
1349         return file;
1350 }
1351
1352
1353 void
1354 signal_hup(int signo)
1355 {
1356         if (mutex)
1357                 sigflags |= (1 << (signo - 1));
1358         else    handle_hup(signo);
1359 }
1360
1361
1362 void
1363 signal_int(int signo)
1364 {
1365         if (mutex)
1366                 sigflags |= (1 << (signo - 1));
1367         else    handle_int(signo);
1368 }
1369
1370
1371 void
1372 handle_hup(int signo)
1373 {
1374         char *hup = NULL;               /* hup filename */
1375         char *s;
1376         int n;
1377
1378         if (!sigactive)
1379                 quit(1);
1380         sigflags &= ~(1 << (signo - 1));
1381         if (addr_last && write_file("ed.hup", "w", 1, addr_last) < 0 &&
1382             (s = getenv("HOME")) != NULL &&
1383             (n = strlen(s)) + 8 <= MAXPATHLEN &&        /* "ed.hup" + '/' */
1384             (hup = (char *) malloc(n + 10)) != NULL) {
1385                 strcpy(hup, s);
1386                 if (hup[n - 1] != '/')
1387                         hup[n] = '/', hup[n+1] = '\0';
1388                 strcat(hup, "ed.hup");
1389                 write_file(hup, "w", 1, addr_last);
1390         }
1391         quit(2);
1392 }
1393
1394
1395 void
1396 handle_int(int signo)
1397 {
1398         if (!sigactive)
1399                 quit(1);
1400         sigflags &= ~(1 << (signo - 1));
1401 #ifdef _POSIX_SOURCE
1402         siglongjmp(env, -1);
1403 #else
1404         longjmp(env, -1);
1405 #endif
1406 }
1407
1408
1409 int cols = 72;                          /* wrap column */
1410
1411 void
1412 handle_winch(int signo)
1413 {
1414         struct winsize ws;              /* window size structure */
1415
1416         sigflags &= ~(1 << (signo - 1));
1417         if (ioctl(0, TIOCGWINSZ, (char *) &ws) >= 0) {
1418                 if (ws.ws_row > 2) rows = ws.ws_row - 2;
1419                 if (ws.ws_col > 8) cols = ws.ws_col - 8;
1420         }
1421 }
1422
1423
1424 /* is_legal_filename: return a legal filename */
1425 int
1426 is_legal_filename(char *s)
1427 {
1428         if (red && (*s == '!' || !strcmp(s, "..") || strchr(s, '/'))) {
1429                 seterrmsg("shell access restricted");
1430                 return 0;
1431         }
1432         return 1;
1433 }