bin/ed/main.c

   1 /* main.c: This file contains the main control and user-interface routines
   2    for the ed line editor. */
   3 /*-
   4  * Copyright (c) 1993 Andrew Moore, Talke Studio.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #ifndef lint
  30 #if 0
  31 static const char copyright[] =
  32 "@(#) Copyright (c) 1993 Andrew Moore, Talke Studio. \n\
  33  All rights reserved.\n";
  34 #endif
  35 #endif /* not lint */
  36
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD$");
  39
  40 /*
  41  * CREDITS
  42  *
  43  *      This program is based on the editor algorithm described in
  44  *      Brian W. Kernighan and P. J. Plauger's book "Software Tools
  45  *      in Pascal," Addison-Wesley, 1981.
  46  *
  47  *      The buffering algorithm is attributed to Rodney Ruddock of
  48  *      the University of Guelph, Guelph, Ontario.
  49  *
  50  *      The cbc.c encryption code is adapted from
  51  *      the bdes program by Matt Bishop of Dartmouth College,
  52  *      Hanover, NH.
  53  *
  54  */
  55
  56 #include <sys/types.h>
  57
  58 #include <sys/ioctl.h>
  59 #include <sys/wait.h>
  60 #include <ctype.h>
  61 #include <locale.h>
  62 #include <pwd.h>
  63 #include <setjmp.h>
  64
  65 #include "ed.h"
  66
  67
  68 #ifdef _POSIX_SOURCE
  69 sigjmp_buf env;
  70 #else
  71 jmp_buf env;
  72 #endif
  73
  74 /* static buffers */
  75 char stdinbuf[1];               /* stdin buffer */
  76 char *shcmd;                    /* shell command buffer */
  77 int shcmdsz;                    /* shell command buffer size */
  78 int shcmdi;                     /* shell command buffer index */
  79 char *ibuf;                     /* ed command-line buffer */
  80 int ibufsz;                     /* ed command-line buffer size */
  81 char *ibufp;                    /* pointer to ed command-line buffer */
  82
  83 /* global flags */
  84 int des = 0;                    /* if set, use crypt(3) for i/o */
  85 int garrulous = 0;              /* if set, print all error messages */
  86 int isbinary;                   /* if set, buffer contains ASCII NULs */
  87 int isglobal;                   /* if set, doing a global command */
  88 int modified;                   /* if set, buffer modified since last write */
  89 int mutex = 0;                  /* if set, signals set "sigflags" */
  90 int red = 0;                    /* if set, restrict shell/directory access */
  91 int scripted = 0;               /* if set, suppress diagnostics */
  92 int sigflags = 0;               /* if set, signals received while mutex set */
  93 int sigactive = 0;              /* if set, signal handlers are enabled */
  94
  95 char old_filename[PATH_MAX] = "";       /* default filename */
  96 long current_addr;              /* current address in editor buffer */
  97 long addr_last;                 /* last address in editor buffer */
  98 int lineno;                     /* script line number */
  99 const char *prompt;             /* command-line prompt */
 100 const char *dps = "*";          /* default command-line prompt */
 101
 102 const char usage[] = "usage: %s [-] [-sx] [-p string] [file]\n";
 103
 104 /* ed: line editor */
 105 int
 106 main(int argc, char *argv[])
 107 {
 108         int c, n;
 109         long status = 0;
 110 #if __GNUC__
 111         /* Avoid longjmp clobbering */
 112         (void) &argc;
 113         (void) &argv;
 114 #endif
 115
 116         (void)setlocale(LC_ALL, "");
 117
 118         red = (n = strlen(argv[0])) > 2 && argv[0][n - 3] == 'r';
 119 top:
 120         while ((c = getopt(argc, argv, "p:sx")) != -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                 default:
 137                         fprintf(stderr, usage, red ? "red" : "ed");
 138                         exit(1);
 139                 }
 140         argv += optind;
 141         argc -= optind;
 142         if (argc && **argv == '-') {
 143                 scripted = 1;
 144                 if (argc > 1) {
 145                         optind = 1;
 146                         goto top;
 147                 }
 148                 argv++;
 149                 argc--;
 150         }
 151         /* assert: reliable signals! */
 152 #ifdef SIGWINCH
 153         handle_winch(SIGWINCH);
 154         if (isatty(0)) signal(SIGWINCH, handle_winch);
 155 #endif
 156         signal(SIGHUP, signal_hup);
 157         signal(SIGQUIT, SIG_IGN);
 158         signal(SIGINT, signal_int);
 159 #ifdef _POSIX_SOURCE
 160         if ((status = sigsetjmp(env, 1)))
 161 #else
 162         if ((status = setjmp(env)))
 163 #endif
 164         {
 165                 fputs("\n?\n", stderr);
 166                 errmsg = "interrupt";
 167         } else {
 168                 init_buffers();
 169                 sigactive = 1;                  /* enable signal handlers */
 170                 if (argc && **argv && is_legal_filename(*argv)) {
 171                         if (read_file(*argv, 0) < 0 && !isatty(0))
 172                                 quit(2);
 173                         else if (**argv != '!')
 174                                 if (strlcpy(old_filename, *argv, sizeof(old_filename))
 175                                     >= sizeof(old_filename))
 176                                         quit(2);
 177                 } else if (argc) {
 178                         fputs("?\n", stderr);
 179                         if (**argv == '\0')
 180                                 errmsg = "invalid filename";
 181                         if (!isatty(0))
 182                                 quit(2);
 183                 }
 184         }
 185         for (;;) {
 186                 if (status < 0 && garrulous)
 187                         fprintf(stderr, "%s\n", errmsg);
 188                 if (prompt) {
 189                         printf("%s", prompt);
 190                         fflush(stdout);
 191                 }
 192                 if ((n = get_tty_line()) < 0) {
 193                         status = ERR;
 194                         continue;
 195                 } else if (n == 0) {
 196                         if (modified && !scripted) {
 197                                 fputs("?\n", stderr);
 198                                 errmsg = "warning: file modified";
 199                                 if (!isatty(0)) {
 200                                         fprintf(stderr, garrulous ?
 201                                             "script, line %d: %s\n" :
 202                                             "", lineno, errmsg);
 203                                         quit(2);
 204                                 }
 205                                 clearerr(stdin);
 206                                 modified = 0;
 207                                 status = EMOD;
 208                                 continue;
 209                         } else
 210                                 quit(0);
 211                 } else if (ibuf[n - 1] != '\n') {
 212                         /* discard line */
 213                         errmsg = "unexpected end-of-file";
 214                         clearerr(stdin);
 215                         status = ERR;
 216                         continue;
 217                 }
 218                 isglobal = 0;
 219                 if ((status = extract_addr_range()) >= 0 &&
 220                     (status = exec_command()) >= 0)
 221                         if (!status ||
 222                             (status = display_lines(current_addr, current_addr,
 223                                 status)) >= 0)
 224                                 continue;
 225                 switch (status) {
 226                 case EOF:
 227                         quit(0);
 228                 case EMOD:
 229                         modified = 0;
 230                         fputs("?\n", stderr);           /* give warning */
 231                         errmsg = "warning: file modified";
 232                         if (!isatty(0)) {
 233                                 fprintf(stderr, garrulous ?
 234                                     "script, line %d: %s\n" :
 235                                     "", lineno, errmsg);
 236                                 quit(2);
 237                         }
 238                         break;
 239                 case FATAL:
 240                         if (!isatty(0))
 241                                 fprintf(stderr, garrulous ?
 242                                     "script, line %d: %s\n" : "",
 243                                     lineno, errmsg);
 244                         else
 245                                 fprintf(stderr, garrulous ? "%s\n" : "",
 246                                     errmsg);
 247                         quit(3);
 248                 default:
 249                         fputs("?\n", stderr);
 250                         if (!isatty(0)) {
 251                                 fprintf(stderr, garrulous ?
 252                                     "script, line %d: %s\n" : "",
 253                                     lineno, errmsg);
 254                                 quit(2);
 255                         }
 256                         break;
 257                 }
 258         }
 259         /*NOTREACHED*/
 260 }
 261
 262 long first_addr, second_addr, addr_cnt;
 263
 264 /* extract_addr_range: get line addresses from the command buffer until an
 265    illegal address is seen; return status */
 266 int
 267 extract_addr_range(void)
 268 {
 269         long addr;
 270
 271         addr_cnt = 0;
 272         first_addr = second_addr = current_addr;
 273         while ((addr = next_addr()) >= 0) {
 274                 addr_cnt++;
 275                 first_addr = second_addr;
 276                 second_addr = addr;
 277                 if (*ibufp != ',' && *ibufp != ';')
 278                         break;
 279                 else if (*ibufp++ == ';')
 280                         current_addr = addr;
 281         }
 282         if ((addr_cnt = min(addr_cnt, 2)) == 1 || second_addr != addr)
 283                 first_addr = second_addr;
 284         return (addr == ERR) ? ERR : 0;
 285 }
 286
 287
 288 #define SKIP_BLANKS() while (isspace((unsigned char)*ibufp) && *ibufp != '\n') ibufp++
 289
 290 #define MUST_BE_FIRST() do {                                    \
 291         if (!first) {                                           \
 292                 errmsg = "invalid address";                     \
 293                 return ERR;                                     \
 294         }                                                       \
 295 } while (0)
 296
 297 /*  next_addr: return the next line address in the command buffer */
 298 long
 299 next_addr(void)
 300 {
 301         const 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(*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                         /* FALLTHROUGH */
 361                 default:
 362                         if (ibufp == hd)
 363                                 return EOF;
 364                         else if (addr < 0 || addr_last < addr) {
 365                                 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                 errmsg = "destination expected"; \
 385                 return ERR; \
 386         } else if (second_addr < 0 || addr_last < second_addr) { \
 387                 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                 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                 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                 /* FALLTHROUGH */
 495         case 'E':
 496                 if (addr_cnt > 0) {
 497                         errmsg = "unexpected address";
 498                         return ERR;
 499                 } else if (!isspace((unsigned char)*ibufp)) {
 500                         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 != '!') strcpy(old_filename, fnp);
 513 #ifdef BACKWARDS
 514                 if (*fnp == '\0' && *old_filename == '\0') {
 515                         errmsg = "no current filename";
 516                         return ERR;
 517                 }
 518 #endif
 519                 if (read_file(*fnp ? fnp : old_filename, 0) < 0)
 520                         return ERR;
 521                 clear_undo_stack();
 522                 modified = 0;
 523                 u_current_addr = u_addr_last = -1;
 524                 break;
 525         case 'f':
 526                 if (addr_cnt > 0) {
 527                         errmsg = "unexpected address";
 528                         return ERR;
 529                 } else if (!isspace((unsigned char)*ibufp)) {
 530                         errmsg = "unexpected command suffix";
 531                         return ERR;
 532                 } else if ((fnp = get_filename()) == NULL)
 533                         return ERR;
 534                 else if (*fnp == '!') {
 535                         errmsg = "invalid redirection";
 536                         return ERR;
 537                 }
 538                 GET_COMMAND_SUFFIX();
 539                 if (*fnp) strcpy(old_filename, fnp);
 540                 printf("%s\n", strip_escapes(old_filename));
 541                 break;
 542         case 'g':
 543         case 'v':
 544         case 'G':
 545         case 'V':
 546                 if (isglobal) {
 547                         errmsg = "cannot nest global commands";
 548                         return ERR;
 549                 } else if (check_addr_range(1, addr_last) < 0)
 550                         return ERR;
 551                 else if (build_active_list(c == 'g' || c == 'G') < 0)
 552                         return ERR;
 553                 else if ((n = (c == 'G' || c == 'V')))
 554                         GET_COMMAND_SUFFIX();
 555                 isglobal++;
 556                 if (exec_global(n, gflag) < 0)
 557                         return ERR;
 558                 break;
 559         case 'h':
 560                 if (addr_cnt > 0) {
 561                         errmsg = "unexpected address";
 562                         return ERR;
 563                 }
 564                 GET_COMMAND_SUFFIX();
 565                 if (*errmsg) fprintf(stderr, "%s\n", errmsg);
 566                 break;
 567         case 'H':
 568                 if (addr_cnt > 0) {
 569                         errmsg = "unexpected address";
 570                         return ERR;
 571                 }
 572                 GET_COMMAND_SUFFIX();
 573                 if ((garrulous = 1 - garrulous) && *errmsg)
 574                         fprintf(stderr, "%s\n", errmsg);
 575                 break;
 576         case 'i':
 577                 if (second_addr == 0) {
 578                         errmsg = "invalid address";
 579                         return ERR;
 580                 }
 581                 GET_COMMAND_SUFFIX();
 582                 if (!isglobal) clear_undo_stack();
 583                 if (append_lines(second_addr - 1) < 0)
 584                         return ERR;
 585                 break;
 586         case 'j':
 587                 if (check_addr_range(current_addr, current_addr + 1) < 0)
 588                         return ERR;
 589                 GET_COMMAND_SUFFIX();
 590                 if (!isglobal) clear_undo_stack();
 591                 if (first_addr != second_addr &&
 592                     join_lines(first_addr, second_addr) < 0)
 593                         return ERR;
 594                 break;
 595         case 'k':
 596                 c = *ibufp++;
 597                 if (second_addr == 0) {
 598                         errmsg = "invalid address";
 599                         return ERR;
 600                 }
 601                 GET_COMMAND_SUFFIX();
 602                 if (mark_line_node(get_addressed_line_node(second_addr), c) < 0)
 603                         return ERR;
 604                 break;
 605         case 'l':
 606                 if (check_addr_range(current_addr, current_addr) < 0)
 607                         return ERR;
 608                 GET_COMMAND_SUFFIX();
 609                 if (display_lines(first_addr, second_addr, gflag | GLS) < 0)
 610                         return ERR;
 611                 gflag = 0;
 612                 break;
 613         case 'm':
 614                 if (check_addr_range(current_addr, current_addr) < 0)
 615                         return ERR;
 616                 GET_THIRD_ADDR(addr);
 617                 if (first_addr <= addr && addr < second_addr) {
 618                         errmsg = "invalid destination";
 619                         return ERR;
 620                 }
 621                 GET_COMMAND_SUFFIX();
 622                 if (!isglobal) clear_undo_stack();
 623                 if (move_lines(addr) < 0)
 624                         return ERR;
 625                 break;
 626         case 'n':
 627                 if (check_addr_range(current_addr, current_addr) < 0)
 628                         return ERR;
 629                 GET_COMMAND_SUFFIX();
 630                 if (display_lines(first_addr, second_addr, gflag | GNP) < 0)
 631                         return ERR;
 632                 gflag = 0;
 633                 break;
 634         case 'p':
 635                 if (check_addr_range(current_addr, current_addr) < 0)
 636                         return ERR;
 637                 GET_COMMAND_SUFFIX();
 638                 if (display_lines(first_addr, second_addr, gflag | GPR) < 0)
 639                         return ERR;
 640                 gflag = 0;
 641                 break;
 642         case 'P':
 643                 if (addr_cnt > 0) {
 644                         errmsg = "unexpected address";
 645                         return ERR;
 646                 }
 647                 GET_COMMAND_SUFFIX();
 648                 prompt = prompt ? NULL : optarg ? optarg : dps;
 649                 break;
 650         case 'q':
 651         case 'Q':
 652                 if (addr_cnt > 0) {
 653                         errmsg = "unexpected address";
 654                         return ERR;
 655                 }
 656                 GET_COMMAND_SUFFIX();
 657                 gflag =  (modified && !scripted && c == 'q') ? EMOD : EOF;
 658                 break;
 659         case 'r':
 660                 if (!isspace((unsigned char)*ibufp)) {
 661                         errmsg = "unexpected command suffix";
 662                         return ERR;
 663                 } else if (addr_cnt == 0)
 664                         second_addr = addr_last;
 665                 if ((fnp = get_filename()) == NULL)
 666                         return ERR;
 667                 GET_COMMAND_SUFFIX();
 668                 if (!isglobal) clear_undo_stack();
 669                 if (*old_filename == '\0' && *fnp != '!')
 670                         strcpy(old_filename, fnp);
 671 #ifdef BACKWARDS
 672                 if (*fnp == '\0' && *old_filename == '\0') {
 673                         errmsg = "no current filename";
 674                         return ERR;
 675                 }
 676 #endif
 677                 if ((addr = read_file(*fnp ? fnp : old_filename, second_addr)) < 0)
 678                         return ERR;
 679                 else if (addr && addr != addr_last)
 680                         modified = 1;
 681                 break;
 682         case 's':
 683                 do {
 684                         switch(*ibufp) {
 685                         case '\n':
 686                                 sflags |=SGF;
 687                                 break;
 688                         case 'g':
 689                                 sflags |= SGG;
 690                                 ibufp++;
 691                                 break;
 692                         case 'p':
 693                                 sflags |= SGP;
 694                                 ibufp++;
 695                                 break;
 696                         case 'r':
 697                                 sflags |= SGR;
 698                                 ibufp++;
 699                                 break;
 700                         case '0': case '1': case '2': case '3': case '4':
 701                         case '5': case '6': case '7': case '8': case '9':
 702                                 STRTOL(sgnum, ibufp);
 703                                 sflags |= SGF;
 704                                 sgflag &= ~GSG;         /* override GSG */
 705                                 break;
 706                         default:
 707                                 if (sflags) {
 708                                         errmsg = "invalid command suffix";
 709                                         return ERR;
 710                                 }
 711                         }
 712                 } while (sflags && *ibufp != '\n');
 713                 if (sflags && !pat) {
 714                         errmsg = "no previous substitution";
 715                         return ERR;
 716                 } else if (sflags & SGG)
 717                         sgnum = 0;              /* override numeric arg */
 718                 if (*ibufp != '\n' && *(ibufp + 1) == '\n') {
 719                         errmsg = "invalid pattern delimiter";
 720                         return ERR;
 721                 }
 722                 tpat = pat;
 723                 SPL1();
 724                 if ((!sflags || (sflags & SGR)) &&
 725                     (tpat = get_compiled_pattern()) == NULL) {
 726                         SPL0();
 727                         return ERR;
 728                 } else if (tpat != pat) {
 729                         if (pat) {
 730                                 regfree(pat);
 731                                 free(pat);
 732                         }
 733                         pat = tpat;
 734                         patlock = 1;            /* reserve pattern */
 735                 }
 736                 SPL0();
 737                 if (!sflags && extract_subst_tail(&sgflag, &sgnum) < 0)
 738                         return ERR;
 739                 else if (isglobal)
 740                         sgflag |= GLB;
 741                 else
 742                         sgflag &= ~GLB;
 743                 if (sflags & SGG)
 744                         sgflag ^= GSG;
 745                 if (sflags & SGP)
 746                         sgflag ^= GPR, sgflag &= ~(GLS | GNP);
 747                 do {
 748                         switch(*ibufp) {
 749                         case 'p':
 750                                 sgflag |= GPR, ibufp++;
 751                                 break;
 752                         case 'l':
 753                                 sgflag |= GLS, ibufp++;
 754                                 break;
 755                         case 'n':
 756                                 sgflag |= GNP, ibufp++;
 757                                 break;
 758                         default:
 759                                 n++;
 760                         }
 761                 } while (!n);
 762                 if (check_addr_range(current_addr, current_addr) < 0)
 763                         return ERR;
 764                 GET_COMMAND_SUFFIX();
 765                 if (!isglobal) clear_undo_stack();
 766                 if (search_and_replace(pat, sgflag, sgnum) < 0)
 767                         return ERR;
 768                 break;
 769         case 't':
 770                 if (check_addr_range(current_addr, current_addr) < 0)
 771                         return ERR;
 772                 GET_THIRD_ADDR(addr);
 773                 GET_COMMAND_SUFFIX();
 774                 if (!isglobal) clear_undo_stack();
 775                 if (copy_lines(addr) < 0)
 776                         return ERR;
 777                 break;
 778         case 'u':
 779                 if (addr_cnt > 0) {
 780                         errmsg = "unexpected address";
 781                         return ERR;
 782                 }
 783                 GET_COMMAND_SUFFIX();
 784                 if (pop_undo_stack() < 0)
 785                         return ERR;
 786                 break;
 787         case 'w':
 788         case 'W':
 789                 if ((n = *ibufp) == 'q' || n == 'Q') {
 790                         gflag = EOF;
 791                         ibufp++;
 792                 }
 793                 if (!isspace((unsigned char)*ibufp)) {
 794                         errmsg = "unexpected command suffix";
 795                         return ERR;
 796                 } else if ((fnp = get_filename()) == NULL)
 797                         return ERR;
 798                 if (addr_cnt == 0 && !addr_last)
 799                         first_addr = second_addr = 0;
 800                 else if (check_addr_range(1, addr_last) < 0)
 801                         return ERR;
 802                 GET_COMMAND_SUFFIX();
 803                 if (*old_filename == '\0' && *fnp != '!')
 804                         strcpy(old_filename, fnp);
 805 #ifdef BACKWARDS
 806                 if (*fnp == '\0' && *old_filename == '\0') {
 807                         errmsg = "no current filename";
 808                         return ERR;
 809                 }
 810 #endif
 811                 if ((addr = write_file(*fnp ? fnp : old_filename,
 812                     (c == 'W') ? "a" : "w", first_addr, second_addr)) < 0)
 813                         return ERR;
 814                 else if (addr == addr_last)
 815                         modified = 0;
 816                 else if (modified && !scripted && n == 'q')
 817                         gflag = EMOD;
 818                 break;
 819         case 'x':
 820                 if (addr_cnt > 0) {
 821                         errmsg = "unexpected address";
 822                         return ERR;
 823                 }
 824                 GET_COMMAND_SUFFIX();
 825 #ifdef DES
 826                 des = get_keyword();
 827                 break;
 828 #else
 829                 errmsg = "crypt unavailable";
 830                 return ERR;
 831 #endif
 832         case 'z':
 833 #ifdef BACKWARDS
 834                 if (check_addr_range(first_addr = 1, current_addr + 1) < 0)
 835 #else
 836                 if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0)
 837 #endif
 838                         return ERR;
 839                 else if ('0' < *ibufp && *ibufp <= '9')
 840                         STRTOL(rows, ibufp);
 841                 GET_COMMAND_SUFFIX();
 842                 if (display_lines(second_addr, min(addr_last,
 843                     second_addr + rows), gflag) < 0)
 844                         return ERR;
 845                 gflag = 0;
 846                 break;
 847         case '=':
 848                 GET_COMMAND_SUFFIX();
 849                 printf("%ld\n", addr_cnt ? second_addr : addr_last);
 850                 break;
 851         case '!':
 852                 if (addr_cnt > 0) {
 853                         errmsg = "unexpected address";
 854                         return ERR;
 855                 } else if ((sflags = get_shell_command()) < 0)
 856                         return ERR;
 857                 GET_COMMAND_SUFFIX();
 858                 if (sflags) printf("%s\n", shcmd + 1);
 859                 system(shcmd + 1);
 860                 if (!scripted) printf("!\n");
 861                 break;
 862         case '\n':
 863 #ifdef BACKWARDS
 864                 if (check_addr_range(first_addr = 1, current_addr + 1) < 0
 865 #else
 866                 if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0
 867 #endif
 868                  || display_lines(second_addr, second_addr, 0) < 0)
 869                         return ERR;
 870                 break;
 871         default:
 872                 errmsg = "unknown command";
 873                 return ERR;
 874         }
 875         return gflag;
 876 }
 877
 878
 879 /* check_addr_range: return status of address range check */
 880 int
 881 check_addr_range(long n, long m)
 882 {
 883         if (addr_cnt == 0) {
 884                 first_addr = n;
 885                 second_addr = m;
 886         }
 887         if (first_addr > second_addr || 1 > first_addr ||
 888             second_addr > addr_last) {
 889                 errmsg = "invalid address";
 890                 return ERR;
 891         }
 892         return 0;
 893 }
 894
 895
 896 /* get_matching_node_addr: return the address of the next line matching a
 897    pattern in a given direction.  wrap around begin/end of editor buffer if
 898    necessary */
 899 long
 900 get_matching_node_addr(pattern_t *pat, int dir)
 901 {
 902         char *s;
 903         long n = current_addr;
 904         line_t *lp;
 905
 906         if (!pat) return ERR;
 907         do {
 908                if ((n = dir ? INC_MOD(n, addr_last) : DEC_MOD(n, addr_last))) {
 909                         lp = get_addressed_line_node(n);
 910                         if ((s = get_sbuf_line(lp)) == NULL)
 911                                 return ERR;
 912                         if (isbinary)
 913                                 NUL_TO_NEWLINE(s, lp->len);
 914                         if (!regexec(pat, s, 0, NULL, 0))
 915                                 return n;
 916                }
 917         } while (n != current_addr);
 918         errmsg = "no match";
 919         return  ERR;
 920 }
 921
 922
 923 /* get_filename: return pointer to copy of filename in the command buffer */
 924 char *
 925 get_filename(void)
 926 {
 927         static char *file = NULL;
 928         static int filesz = 0;
 929
 930         int n;
 931
 932         if (*ibufp != '\n') {
 933                 SKIP_BLANKS();
 934                 if (*ibufp == '\n') {
 935                         errmsg = "invalid filename";
 936                         return NULL;
 937                 } else if ((ibufp = get_extended_line(&n, 1)) == NULL)
 938                         return NULL;
 939                 else if (*ibufp == '!') {
 940                         ibufp++;
 941                         if ((n = get_shell_command()) < 0)
 942                                 return NULL;
 943                         if (n)
 944                                 printf("%s\n", shcmd + 1);
 945                         return shcmd;
 946                 } else if (n > PATH_MAX - 1) {
 947                         errmsg = "filename too long";
 948                         return  NULL;
 949                 }
 950         }
 951 #ifndef BACKWARDS
 952         else if (*old_filename == '\0') {
 953                 errmsg = "no current filename";
 954                 return  NULL;
 955         }
 956 #endif
 957         REALLOC(file, filesz, PATH_MAX, NULL);
 958         for (n = 0; *ibufp != '\n';)
 959                 file[n++] = *ibufp++;
 960         file[n] = '\0';
 961         return is_legal_filename(file) ? file : NULL;
 962 }
 963
 964
 965 /* get_shell_command: read a shell command from stdin; return substitution
 966    status */
 967 int
 968 get_shell_command(void)
 969 {
 970         static char *buf = NULL;
 971         static int n = 0;
 972
 973         char *s;                        /* substitution char pointer */
 974         int i = 0;
 975         int j = 0;
 976
 977         if (red) {
 978                 errmsg = "shell access restricted";
 979                 return ERR;
 980         } else if ((s = ibufp = get_extended_line(&j, 1)) == NULL)
 981                 return ERR;
 982         REALLOC(buf, n, j + 1, ERR);
 983         buf[i++] = '!';                 /* prefix command w/ bang */
 984         while (*ibufp != '\n')
 985                 switch (*ibufp) {
 986                 default:
 987                         REALLOC(buf, n, i + 2, ERR);
 988                         buf[i++] = *ibufp;
 989                         if (*ibufp++ == '\\')
 990                                 buf[i++] = *ibufp++;
 991                         break;
 992                 case '!':
 993                         if (s != ibufp) {
 994                                 REALLOC(buf, n, i + 1, ERR);
 995                                 buf[i++] = *ibufp++;
 996                         }
 997 #ifdef BACKWARDS
 998                         else if (shcmd == NULL || *(shcmd + 1) == '\0')
 999 #else
1000                         else if (shcmd == NULL)
1001 #endif
1002                         {
1003                                 errmsg = "no previous command";
1004                                 return ERR;
1005                         } else {
1006                                 REALLOC(buf, n, i + shcmdi, ERR);
1007                                 for (s = shcmd + 1; s < shcmd + shcmdi;)
1008                                         buf[i++] = *s++;
1009                                 s = ibufp++;
1010                         }
1011                         break;
1012                 case '%':
1013                         if (*old_filename  == '\0') {
1014                                 errmsg = "no current filename";
1015                                 return ERR;
1016                         }
1017                         j = strlen(s = strip_escapes(old_filename));
1018                         REALLOC(buf, n, i + j, ERR);
1019                         while (j--)
1020                                 buf[i++] = *s++;
1021                         s = ibufp++;
1022                         break;
1023                 }
1024         REALLOC(shcmd, shcmdsz, i + 1, ERR);
1025         memcpy(shcmd, buf, i);
1026         shcmd[shcmdi = i] = '\0';
1027         return *s == '!' || *s == '%';
1028 }
1029
1030
1031 /* append_lines: insert text from stdin to after line n; stop when either a
1032    single period is read or EOF; return status */
1033 int
1034 append_lines(long n)
1035 {
1036         int l;
1037         const char *lp = ibuf;
1038         const char *eot;
1039         undo_t *up = NULL;
1040
1041         for (current_addr = n;;) {
1042                 if (!isglobal) {
1043                         if ((l = get_tty_line()) < 0)
1044                                 return ERR;
1045                         else if (l == 0 || ibuf[l - 1] != '\n') {
1046                                 clearerr(stdin);
1047                                 return  l ? EOF : 0;
1048                         }
1049                         lp = ibuf;
1050                 } else if (*(lp = ibufp) == '\0')
1051                         return 0;
1052                 else {
1053                         while (*ibufp++ != '\n')
1054                                 ;
1055                         l = ibufp - lp;
1056                 }
1057                 if (l == 2 && lp[0] == '.' && lp[1] == '\n') {
1058                         return 0;
1059                 }
1060                 eot = lp + l;
1061                 SPL1();
1062                 do {
1063                         if ((lp = put_sbuf_line(lp)) == NULL) {
1064                                 SPL0();
1065                                 return ERR;
1066                         } else if (up)
1067                                 up->t = get_addressed_line_node(current_addr);
1068                         else if ((up = push_undo_stack(UADD, current_addr,
1069                             current_addr)) == NULL) {
1070                                 SPL0();
1071                                 return ERR;
1072                         }
1073                 } while (lp != eot);
1074                 modified = 1;
1075                 SPL0();
1076         }
1077         /* NOTREACHED */
1078 }
1079
1080
1081 /* join_lines: replace a range of lines with the joined text of those lines */
1082 int
1083 join_lines(long from, long to)
1084 {
1085         static char *buf = NULL;
1086         static int n;
1087
1088         char *s;
1089         int size = 0;
1090         line_t *bp, *ep;
1091
1092         ep = get_addressed_line_node(INC_MOD(to, addr_last));
1093         bp = get_addressed_line_node(from);
1094         for (; bp != ep; bp = bp->q_forw) {
1095                 if ((s = get_sbuf_line(bp)) == NULL)
1096                         return ERR;
1097                 REALLOC(buf, n, size + bp->len, ERR);
1098                 memcpy(buf + size, s, bp->len);
1099                 size += bp->len;
1100         }
1101         REALLOC(buf, n, size + 2, ERR);
1102         memcpy(buf + size, "\n", 2);
1103         if (delete_lines(from, to) < 0)
1104                 return ERR;
1105         current_addr = from - 1;
1106         SPL1();
1107         if (put_sbuf_line(buf) == NULL ||
1108             push_undo_stack(UADD, current_addr, current_addr) == NULL) {
1109                 SPL0();
1110                 return ERR;
1111         }
1112         modified = 1;
1113         SPL0();
1114         return 0;
1115 }
1116
1117
1118 /* move_lines: move a range of lines */
1119 int
1120 move_lines(long addr)
1121 {
1122         line_t *b1, *a1, *b2, *a2;
1123         long n = INC_MOD(second_addr, addr_last);
1124         long p = first_addr - 1;
1125         int done = (addr == first_addr - 1 || addr == second_addr);
1126
1127         SPL1();
1128         if (done) {
1129                 a2 = get_addressed_line_node(n);
1130                 b2 = get_addressed_line_node(p);
1131                 current_addr = second_addr;
1132         } else if (push_undo_stack(UMOV, p, n) == NULL ||
1133             push_undo_stack(UMOV, addr, INC_MOD(addr, addr_last)) == NULL) {
1134                 SPL0();
1135                 return ERR;
1136         } else {
1137                 a1 = get_addressed_line_node(n);
1138                 if (addr < first_addr) {
1139                         b1 = get_addressed_line_node(p);
1140                         b2 = get_addressed_line_node(addr);
1141                                         /* this get_addressed_line_node last! */
1142                 } else {
1143                         b2 = get_addressed_line_node(addr);
1144                         b1 = get_addressed_line_node(p);
1145                                         /* this get_addressed_line_node last! */
1146                 }
1147                 a2 = b2->q_forw;
1148                 REQUE(b2, b1->q_forw);
1149                 REQUE(a1->q_back, a2);
1150                 REQUE(b1, a1);
1151                 current_addr = addr + ((addr < first_addr) ?
1152                     second_addr - first_addr + 1 : 0);
1153         }
1154         if (isglobal)
1155                 unset_active_nodes(b2->q_forw, a2);
1156         modified = 1;
1157         SPL0();
1158         return 0;
1159 }
1160
1161
1162 /* copy_lines: copy a range of lines; return status */
1163 int
1164 copy_lines(long addr)
1165 {
1166         line_t *lp, *np = get_addressed_line_node(first_addr);
1167         undo_t *up = NULL;
1168         long n = second_addr - first_addr + 1;
1169         long m = 0;
1170
1171         current_addr = addr;
1172         if (first_addr <= addr && addr < second_addr) {
1173                 n =  addr - first_addr + 1;
1174                 m = second_addr - addr;
1175         }
1176         for (; n > 0; n=m, m=0, np = get_addressed_line_node(current_addr + 1))
1177                 for (; n-- > 0; np = np->q_forw) {
1178                         SPL1();
1179                         if ((lp = dup_line_node(np)) == NULL) {
1180                                 SPL0();
1181                                 return ERR;
1182                         }
1183                         add_line_node(lp);
1184                         if (up)
1185                                 up->t = lp;
1186                         else if ((up = push_undo_stack(UADD, current_addr,
1187                             current_addr)) == NULL) {
1188                                 SPL0();
1189                                 return ERR;
1190                         }
1191                         modified = 1;
1192                         SPL0();
1193                 }
1194         return 0;
1195 }
1196
1197
1198 /* delete_lines: delete a range of lines */
1199 int
1200 delete_lines(long from, long to)
1201 {
1202         line_t *n, *p;
1203
1204         SPL1();
1205         if (push_undo_stack(UDEL, from, to) == NULL) {
1206                 SPL0();
1207                 return ERR;
1208         }
1209         n = get_addressed_line_node(INC_MOD(to, addr_last));
1210         p = get_addressed_line_node(from - 1);
1211                                         /* this get_addressed_line_node last! */
1212         if (isglobal)
1213                 unset_active_nodes(p->q_forw, n);
1214         REQUE(p, n);
1215         addr_last -= to - from + 1;
1216         current_addr = from - 1;
1217         modified = 1;
1218         SPL0();
1219         return 0;
1220 }
1221
1222
1223 /* display_lines: print a range of lines to stdout */
1224 int
1225 display_lines(long from, long to, int gflag)
1226 {
1227         line_t *bp;
1228         line_t *ep;
1229         char *s;
1230
1231         if (!from) {
1232                 errmsg = "invalid address";
1233                 return ERR;
1234         }
1235         ep = get_addressed_line_node(INC_MOD(to, addr_last));
1236         bp = get_addressed_line_node(from);
1237         for (; bp != ep; bp = bp->q_forw) {
1238                 if ((s = get_sbuf_line(bp)) == NULL)
1239                         return ERR;
1240                 if (put_tty_line(s, bp->len, current_addr = from++, gflag) < 0)
1241                         return ERR;
1242         }
1243         return 0;
1244 }
1245
1246
1247 #define MAXMARK 26                      /* max number of marks */
1248
1249 line_t  *mark[MAXMARK];                 /* line markers */
1250 int markno;                             /* line marker count */
1251
1252 /* mark_line_node: set a line node mark */
1253 int
1254 mark_line_node(line_t *lp, int n)
1255 {
1256         if (!islower((unsigned char)n)) {
1257                 errmsg = "invalid mark character";
1258                 return ERR;
1259         } else if (mark[n - 'a'] == NULL)
1260                 markno++;
1261         mark[n - 'a'] = lp;
1262         return 0;
1263 }
1264
1265
1266 /* get_marked_node_addr: return address of a marked line */
1267 long
1268 get_marked_node_addr(int n)
1269 {
1270         if (!islower((unsigned char)n)) {
1271                 errmsg = "invalid mark character";
1272                 return ERR;
1273         }
1274         return get_line_node_addr(mark[n - 'a']);
1275 }
1276
1277
1278 /* unmark_line_node: clear line node mark */
1279 void
1280 unmark_line_node(line_t *lp)
1281 {
1282         int i;
1283
1284         for (i = 0; markno && i < MAXMARK; i++)
1285                 if (mark[i] == lp) {
1286                         mark[i] = NULL;
1287                         markno--;
1288                 }
1289 }
1290
1291
1292 /* dup_line_node: return a pointer to a copy of a line node */
1293 line_t *
1294 dup_line_node(line_t *lp)
1295 {
1296         line_t *np;
1297
1298         if ((np = (line_t *) malloc(sizeof(line_t))) == NULL) {
1299                 fprintf(stderr, "%s\n", strerror(errno));
1300                 errmsg = "out of memory";
1301                 return NULL;
1302         }
1303         np->seek = lp->seek;
1304         np->len = lp->len;
1305         return np;
1306 }
1307
1308
1309 /* has_trailing_escape:  return the parity of escapes preceding a character
1310    in a string */
1311 int
1312 has_trailing_escape(char *s, char *t)
1313 {
1314     return (s == t || *(t - 1) != '\\') ? 0 : !has_trailing_escape(s, t - 1);
1315 }
1316
1317
1318 /* strip_escapes: return copy of escaped string of at most length PATH_MAX */
1319 char *
1320 strip_escapes(char *s)
1321 {
1322         static char *file = NULL;
1323         static int filesz = 0;
1324
1325         int i = 0;
1326
1327         REALLOC(file, filesz, PATH_MAX, NULL);
1328         while (i < filesz - 1   /* Worry about a possible trailing escape */
1329                && (file[i++] = (*s == '\\') ? *++s : *s))
1330                 s++;
1331         return file;
1332 }
1333
1334
1335 void
1336 signal_hup(int signo)
1337 {
1338         if (mutex)
1339                 sigflags |= (1 << (signo - 1));
1340         else
1341                 handle_hup(signo);
1342 }
1343
1344
1345 void
1346 signal_int(int signo)
1347 {
1348         if (mutex)
1349                 sigflags |= (1 << (signo - 1));
1350         else
1351                 handle_int(signo);
1352 }
1353
1354
1355 void
1356 handle_hup(int signo)
1357 {
1358         char *hup = NULL;               /* hup filename */
1359         char *s;
1360         char ed_hup[] = "ed.hup";
1361         int n;
1362
1363         if (!sigactive)
1364                 quit(1);
1365         sigflags &= ~(1 << (signo - 1));
1366         if (addr_last && write_file(ed_hup, "w", 1, addr_last) < 0 &&
1367             (s = getenv("HOME")) != NULL &&
1368             (n = strlen(s)) + 8 <= PATH_MAX &&  /* "ed.hup" + '/' */
1369             (hup = (char *) malloc(n + 10)) != NULL) {
1370                 strcpy(hup, s);
1371                 if (hup[n - 1] != '/')
1372                         hup[n] = '/', hup[n+1] = '\0';
1373                 strcat(hup, "ed.hup");
1374                 write_file(hup, "w", 1, addr_last);
1375         }
1376         quit(2);
1377 }
1378
1379
1380 void
1381 handle_int(int signo)
1382 {
1383         if (!sigactive)
1384                 quit(1);
1385         sigflags &= ~(1 << (signo - 1));
1386 #ifdef _POSIX_SOURCE
1387         siglongjmp(env, -1);
1388 #else
1389         longjmp(env, -1);
1390 #endif
1391 }
1392
1393
1394 int cols = 72;                          /* wrap column */
1395
1396 void
1397 handle_winch(int signo)
1398 {
1399         int save_errno = errno;
1400
1401         struct winsize ws;              /* window size structure */
1402
1403         sigflags &= ~(1 << (signo - 1));
1404         if (ioctl(0, TIOCGWINSZ, (char *) &ws) >= 0) {
1405                 if (ws.ws_row > 2) rows = ws.ws_row - 2;
1406                 if (ws.ws_col > 8) cols = ws.ws_col - 8;
1407         }
1408         errno = save_errno;
1409 }
1410
1411
1412 /* is_legal_filename: return a legal filename */
1413 int
1414 is_legal_filename(char *s)
1415 {
1416         if (red && (*s == '!' || !strcmp(s, "..") || strchr(s, '/'))) {
1417                 errmsg = "shell access restricted";
1418                 return 0;
1419         }
1420         return 1;
1421 }