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