bin/ed/main.c

   1 /*      $OpenBSD: main.c,v 1.35 2013/01/15 20:26:28 espie Exp $ */
   2 /*      $NetBSD: main.c,v 1.3 1995/03/21 09:04:44 cgd Exp $     */
   3
   4 /* main.c: This file contains the main control and user-interface routines
   5    for the ed line editor. */
   6 /*-
   7  * Copyright (c) 1993 Andrew Moore, Talke Studio.
   8  * All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 /*
  33  * CREDITS
  34  *
  35  *      This program is based on the editor algorithm described in
  36  *      Brian W. Kernighan and P. J. Plauger's book "Software Tools
  37  *      in Pascal," Addison-Wesley, 1981.
  38  *
  39  *      The buffering algorithm is attributed to Rodney Ruddock of
  40  *      the University of Guelph, Guelph, Ontario.
  41  *
  42  *      The cbc.c encryption code is adapted from
  43  *      the bdes program by Matt Bishop of Dartmouth College,
  44  *      Hanover, NH.
  45  *
  46  */
  47
  48 #include <sys/ioctl.h>
  49 #include <sys/stat.h>
  50 #include <sys/wait.h>
  51 #include <ctype.h>
  52 #include <setjmp.h>
  53 #include <unistd.h>
  54 #include <pwd.h>
  55
  56 #include "ed.h"
  57
  58
  59 #ifdef _POSIX_SOURCE
  60 sigjmp_buf env;
  61 #else
  62 jmp_buf env;
  63 #endif
  64
  65 /* static buffers */
  66 char stdinbuf[1];               /* stdin buffer */
  67 char *shcmd;                    /* shell command buffer */
  68 int shcmdsz;                    /* shell command buffer size */
  69 int shcmdi;                     /* shell command buffer index */
  70 char *ibuf;                     /* ed command-line buffer */
  71 int ibufsz;                     /* ed command-line buffer size */
  72 char *ibufp;                    /* pointer to ed command-line buffer */
  73
  74 /* global flags */
  75 int des = 0;                    /* if set, use crypt(3) for i/o */
  76 int garrulous = 0;              /* if set, print all error messages */
  77 int isbinary;                   /* if set, buffer contains ASCII NULs */
  78 int isglobal;                   /* if set, doing a global command */
  79 int modified;                   /* if set, buffer modified since last write */
  80 int mutex = 0;                  /* if set, signals set "sigflags" */
  81 int red = 0;                    /* if set, restrict shell/directory access */
  82 int scripted = 0;               /* if set, suppress diagnostics */
  83 int sigflags = 0;               /* if set, signals received while mutex set */
  84 int interactive = 0;            /* if set, we are in interactive mode */
  85
  86 /* if set, signal handlers are enabled */
  87 volatile sig_atomic_t sigactive = 0;
  88
  89 char old_filename[MAXPATHLEN] = "";     /* default filename */
  90 int current_addr;               /* current address in editor buffer */
  91 int addr_last;                  /* last address in editor buffer */
  92 int lineno;                     /* script line number */
  93 char *prompt;                   /* command-line prompt */
  94 char *dps = "*";                /* default command-line prompt */
  95
  96 char *usage = "usage: %s [-] [-sx] [-p string] [file]\n";
  97
  98 char *home;             /* home directory */
  99
 100 void
 101 seterrmsg(char *s)
 102 {
 103         strlcpy(errmsg, s, sizeof(errmsg));
 104 }
 105
 106 /* ed: line editor */
 107 int
 108 main(volatile int argc, char ** volatile argv)
 109 {
 110         int c, n;
 111         int status = 0;
 112
 113         home = getenv("HOME");
 114
 115         red = (n = strlen(argv[0])) > 2 && argv[0][n - 3] == 'r';
 116 top:
 117         while ((c = getopt(argc, argv, "p:sx")) != -1)
 118                 switch (c) {
 119                 case 'p':                               /* set prompt */
 120                         prompt = optarg;
 121                         break;
 122                 case 's':                               /* run script */
 123                         scripted = 1;
 124                         break;
 125                 case 'x':                               /* use crypt */
 126 #ifdef DES
 127                         des = get_keyword();
 128 #else
 129                         fprintf(stderr, "crypt unavailable\n?\n");
 130 #endif
 131                         break;
 132
 133                 default:
 134                         fprintf(stderr, usage, argv[0]);
 135                         exit(1);
 136                 }
 137         argv += optind;
 138         argc -= optind;
 139         if (argc && **argv == '-') {
 140                 scripted = 1;
 141                 if (argc > 1) {
 142                         optind = 1;
 143                         goto top;
 144                 }
 145                 argv++;
 146                 argc--;
 147         }
 148
 149         if (!(interactive = isatty(0))) {
 150                 struct stat sb;
 151
 152                 /* assert: pipes show up as fifo's when fstat'd */
 153                 if (fstat(STDIN_FILENO, &sb) || !S_ISFIFO(sb.st_mode)) {
 154                         if (lseek(STDIN_FILENO, 0, SEEK_CUR)) {
 155                                 interactive = 1;
 156                                 setlinebuf(stdout);
 157                         }
 158                 }
 159         }
 160
 161         /* assert: reliable signals! */
 162 #ifdef SIGWINCH
 163         if (isatty(STDIN_FILENO)) {
 164                 handle_winch(SIGWINCH);
 165                 signal(SIGWINCH, handle_winch);
 166         }
 167 #endif
 168         signal(SIGHUP, signal_hup);
 169         signal(SIGQUIT, SIG_IGN);
 170         signal(SIGINT, signal_int);
 171 #ifdef _POSIX_SOURCE
 172         if (status = sigsetjmp(env, 1))
 173 #else
 174         if ((status = setjmp(env)) != 0)
 175 #endif
 176         {
 177                 fputs("\n?\n", stderr);
 178                 seterrmsg("interrupt");
 179         } else {
 180                 init_buffers();
 181                 sigactive = 1;                  /* enable signal handlers */
 182                 if (argc && **argv && is_legal_filename(*argv)) {
 183                         if (read_file(*argv, 0) < 0 && !interactive)
 184                                 quit(2);
 185                         else if (**argv != '!')
 186                                 strlcpy(old_filename, *argv,
 187                                     sizeof old_filename);
 188                 } else if (argc) {
 189                         fputs("?\n", stderr);
 190                         if (**argv == '\0')
 191                                 seterrmsg("invalid filename");
 192                         if (!interactive)
 193                                 quit(2);
 194                 }
 195         }
 196         for (;;) {
 197                 if (status < 0 && garrulous)
 198                         fprintf(stderr, "%s\n", errmsg);
 199                 if (prompt) {
 200                         fputs(prompt, stdout);
 201                         fflush(stdout);
 202                 }
 203                 if ((n = get_tty_line()) < 0) {
 204                         status = ERR;
 205                         continue;
 206                 } else if (n == 0) {
 207                         if (modified && !scripted) {
 208                                 fputs("?\n", stderr);
 209                                 seterrmsg("warning: file modified");
 210                                 if (!interactive) {
 211                                         fprintf(stderr, garrulous ?
 212                                             "script, line %d: %s\n" :
 213                                             "", lineno, errmsg);
 214                                         quit(2);
 215                                 }
 216                                 clearerr(stdin);
 217                                 modified = 0;
 218                                 status = EMOD;
 219                                 continue;
 220                         } else
 221                                 quit(0);
 222                 } else if (ibuf[n - 1] != '\n') {
 223                         /* discard line */
 224                         seterrmsg("unexpected end-of-file");
 225                         clearerr(stdin);
 226                         status = ERR;
 227                         continue;
 228                 }
 229                 isglobal = 0;
 230                 if ((status = extract_addr_range()) >= 0 &&
 231                     (status = exec_command()) >= 0)
 232                         if (!status || (status &&
 233                             (status = display_lines(current_addr, current_addr,
 234                                 status)) >= 0))
 235                                 continue;
 236                 switch (status) {
 237                 case EOF:
 238                         quit(0);
 239                 case EMOD:
 240                         modified = 0;
 241                         fputs("?\n", stderr);           /* give warning */
 242                         seterrmsg("warning: file modified");
 243                         if (!interactive) {
 244                                 fprintf(stderr, garrulous ?
 245                                     "script, line %d: %s\n" :
 246                                     "", lineno, errmsg);
 247                                 quit(2);
 248                         }
 249                         break;
 250                 case FATAL:
 251                         if (!interactive)
 252                                 fprintf(stderr, garrulous ?
 253                                     "script, line %d: %s\n" : "",
 254                                     lineno, errmsg);
 255                         else
 256                                 fprintf(stderr, garrulous ? "%s\n" : "",
 257                                     errmsg);
 258                         quit(3);
 259                 default:
 260                         fputs("?\n", stderr);
 261                         if (!interactive) {
 262                                 fprintf(stderr, garrulous ?
 263                                     "script, line %d: %s\n" : "",
 264                                     lineno, errmsg);
 265                                 quit(2);
 266                         }
 267                         break;
 268                 }
 269         }
 270         /*NOTREACHED*/
 271 }
 272
 273 int first_addr, second_addr, addr_cnt;
 274
 275 /* extract_addr_range: get line addresses from the command buffer until an
 276    illegal address is seen; return status */
 277 int
 278 extract_addr_range(void)
 279 {
 280         int addr;
 281
 282         addr_cnt = 0;
 283         first_addr = second_addr = current_addr;
 284         while ((addr = next_addr()) >= 0) {
 285                 addr_cnt++;
 286                 first_addr = second_addr;
 287                 second_addr = addr;
 288                 if (*ibufp != ',' && *ibufp != ';')
 289                         break;
 290                 else if (*ibufp++ == ';')
 291                         current_addr = addr;
 292         }
 293         if ((addr_cnt = min(addr_cnt, 2)) == 1 || second_addr != addr)
 294                 first_addr = second_addr;
 295         return (addr == ERR) ? ERR : 0;
 296 }
 297
 298
 299 #define SKIP_BLANKS() \
 300         do { \
 301                 while (isspace(*ibufp) && *ibufp != '\n') \
 302                         ibufp++; \
 303         } while (0)
 304
 305 #define MUST_BE_FIRST() \
 306         do { \
 307                 if (!first) { \
 308                         seterrmsg("invalid address"); \
 309                         return ERR; \
 310                 } \
 311         } while (0)
 312
 313
 314 /*  next_addr: return the next line address in the command buffer */
 315 int
 316 next_addr(void)
 317 {
 318         char *hd;
 319         int addr = current_addr;
 320         int n;
 321         int first = 1;
 322         int c;
 323
 324         SKIP_BLANKS();
 325         for (hd = ibufp;; first = 0)
 326                 switch ((c = *ibufp)) {
 327                 case '+':
 328                 case '\t':
 329                 case ' ':
 330                 case '-':
 331                 case '^':
 332                         ibufp++;
 333                         SKIP_BLANKS();
 334                         if (isdigit(*ibufp)) {
 335                                 STRTOI(n, ibufp);
 336                                 addr += (c == '-' || c == '^') ? -n : n;
 337                         } else if (!isspace(c))
 338                                 addr += (c == '-' || c == '^') ? -1 : 1;
 339                         break;
 340                 case '0': case '1': case '2':
 341                 case '3': case '4': case '5':
 342                 case '6': case '7': case '8': case '9':
 343                         MUST_BE_FIRST();
 344                         STRTOI(addr, ibufp);
 345                         break;
 346                 case '.':
 347                 case '$':
 348                         MUST_BE_FIRST();
 349                         ibufp++;
 350                         addr = (c == '.') ? current_addr : addr_last;
 351                         break;
 352                 case '/':
 353                 case '?':
 354                         MUST_BE_FIRST();
 355                         if ((addr = get_matching_node_addr(
 356                             get_compiled_pattern(), c == '/')) < 0)
 357                                 return ERR;
 358                         else if (c == *ibufp)
 359                                 ibufp++;
 360                         break;
 361                 case '\'':
 362                         MUST_BE_FIRST();
 363                         ibufp++;
 364                         if ((addr = get_marked_node_addr(*ibufp++)) < 0)
 365                                 return ERR;
 366                         break;
 367                 case '%':
 368                 case ',':
 369                 case ';':
 370                         if (first) {
 371                                 ibufp++;
 372                                 addr_cnt++;
 373                                 second_addr = (c == ';') ? current_addr : 1;
 374                                 addr = addr_last;
 375                                 break;
 376                         }
 377                         /* FALLTHROUGH */
 378                 default:
 379                         if (ibufp == hd)
 380                                 return EOF;
 381                         else if (addr < 0 || addr_last < addr) {
 382                                 seterrmsg("invalid address");
 383                                 return ERR;
 384                         } else
 385                                 return addr;
 386                 }
 387         /* NOTREACHED */
 388 }
 389
 390
 391 #ifdef BACKWARDS
 392 /* GET_THIRD_ADDR: get a legal address from the command buffer */
 393 #define GET_THIRD_ADDR(addr) \
 394         do { \
 395                 int ol1, ol2; \
 396                 \
 397                 ol1 = first_addr; \
 398                 ol2 = second_addr; \
 399                 if (extract_addr_range() < 0) \
 400                         return ERR; \
 401                 else if (addr_cnt == 0) { \
 402                         seterrmsg("destination expected"); \
 403                         return ERR; \
 404                 } else if (second_addr < 0 || addr_last < second_addr) { \
 405                         seterrmsg("invalid address"); \
 406                         return ERR; \
 407                 } \
 408                 addr = second_addr; \
 409                 first_addr = ol1; \
 410                 second_addr = ol2; \
 411         } while (0)
 412
 413 #else   /* BACKWARDS */
 414 /* GET_THIRD_ADDR: get a legal address from the command buffer */
 415 #define GET_THIRD_ADDR(addr) \
 416         do { \
 417                 int ol1, ol2; \
 418                 \
 419                 ol1 = first_addr; \
 420                 ol2 = second_addr; \
 421                 if (extract_addr_range() < 0) \
 422                         return ERR; \
 423                 if (second_addr < 0 || addr_last < second_addr) { \
 424                         seterrmsg("invalid address"); \
 425                         return ERR; \
 426                 } \
 427                 addr = second_addr; \
 428                 first_addr = ol1; \
 429                 second_addr = ol2; \
 430         } while (0)
 431 #endif
 432
 433
 434 /* GET_COMMAND_SUFFIX: verify the command suffix in the command buffer */
 435 #define GET_COMMAND_SUFFIX() \
 436         do { \
 437                 int done = 0; \
 438                 do { \
 439                         switch (*ibufp) { \
 440                         case 'p': \
 441                                 gflag |= GPR; \
 442                                 ibufp++; \
 443                                 break; \
 444                         case 'l': \
 445                                 gflag |= GLS; \
 446                                 ibufp++; \
 447                                 break; \
 448                         case 'n': \
 449                                 gflag |= GNP; \
 450                                 ibufp++; \
 451                                 break; \
 452                         default: \
 453                                 done++; \
 454                         } \
 455                 } while (!done); \
 456                 if (*ibufp++ != '\n') { \
 457                         seterrmsg("invalid command suffix"); \
 458                         return ERR; \
 459                 } \
 460         } while (0)
 461
 462 /* sflags */
 463 #define SGG 001         /* complement previous global substitute suffix */
 464 #define SGP 002         /* complement previous print suffix */
 465 #define SGR 004         /* use last regex instead of last pat */
 466 #define SGF 010         /* repeat last substitution */
 467
 468 int patlock = 0;        /* if set, pattern not freed by get_compiled_pattern() */
 469
 470 volatile sig_atomic_t rows = 22;        /* scroll length: ws_row - 2 */
 471 volatile sig_atomic_t cols = 72;        /* wrap column */
 472
 473 /* exec_command: execute the next command in command buffer; return print
 474    request, if any */
 475 int
 476 exec_command(void)
 477 {
 478         extern int u_current_addr;
 479         extern int u_addr_last;
 480
 481         static pattern_t *pat = NULL;
 482         static int sgflag = 0;
 483         static int sgnum = 0;
 484
 485         pattern_t *tpat;
 486         char *fnp;
 487         int gflag = 0;
 488         int sflags = 0;
 489         int addr = 0;
 490         int n = 0;
 491         int c;
 492
 493         SKIP_BLANKS();
 494         switch ((c = *ibufp++)) {
 495         case 'a':
 496                 GET_COMMAND_SUFFIX();
 497                 if (!isglobal) clear_undo_stack();
 498                 if (append_lines(second_addr) < 0)
 499                         return ERR;
 500                 break;
 501         case 'c':
 502                 if (check_addr_range(current_addr, current_addr) < 0)
 503                         return ERR;
 504                 GET_COMMAND_SUFFIX();
 505                 if (!isglobal) clear_undo_stack();
 506                 if (delete_lines(first_addr, second_addr) < 0 ||
 507                     append_lines(current_addr) < 0)
 508                         return ERR;
 509                 break;
 510         case 'd':
 511                 if (check_addr_range(current_addr, current_addr) < 0)
 512                         return ERR;
 513                 GET_COMMAND_SUFFIX();
 514                 if (!isglobal) clear_undo_stack();
 515                 if (delete_lines(first_addr, second_addr) < 0)
 516                         return ERR;
 517                 else if ((addr = INC_MOD(current_addr, addr_last)) != 0)
 518                         current_addr = addr;
 519                 break;
 520         case 'e':
 521                 if (modified && !scripted)
 522                         return EMOD;
 523                 /* FALLTHROUGH */
 524         case 'E':
 525                 if (addr_cnt > 0) {
 526                         seterrmsg("unexpected address");
 527                         return ERR;
 528                 } else if (!isspace(*ibufp)) {
 529                         seterrmsg("unexpected command suffix");
 530                         return ERR;
 531                 } else if ((fnp = get_filename()) == NULL)
 532                         return ERR;
 533                 GET_COMMAND_SUFFIX();
 534                 if (delete_lines(1, addr_last) < 0)
 535                         return ERR;
 536                 clear_undo_stack();
 537                 if (close_sbuf() < 0)
 538                         return ERR;
 539                 else if (open_sbuf() < 0)
 540                         return FATAL;
 541                 if (*fnp && *fnp != '!')
 542                         strlcpy(old_filename, fnp, sizeof old_filename);
 543 #ifdef BACKWARDS
 544                 if (*fnp == '\0' && *old_filename == '\0') {
 545                         seterrmsg("no current filename");
 546                         return ERR;
 547                 }
 548 #endif
 549                 if (read_file(*fnp ? fnp : old_filename, 0) < 0)
 550                         return ERR;
 551                 clear_undo_stack();
 552                 modified = 0;
 553                 u_current_addr = u_addr_last = -1;
 554                 break;
 555         case 'f':
 556                 if (addr_cnt > 0) {
 557                         seterrmsg("unexpected address");
 558                         return ERR;
 559                 } else if (!isspace(*ibufp)) {
 560                         seterrmsg("unexpected command suffix");
 561                         return ERR;
 562                 } else if ((fnp = get_filename()) == NULL)
 563                         return ERR;
 564                 else if (*fnp == '!') {
 565                         seterrmsg("invalid redirection");
 566                         return ERR;
 567                 }
 568                 GET_COMMAND_SUFFIX();
 569                 if (*fnp)
 570                         strlcpy(old_filename, fnp, sizeof old_filename);
 571                 puts(strip_escapes(old_filename));
 572                 break;
 573         case 'g':
 574         case 'v':
 575         case 'G':
 576         case 'V':
 577                 if (isglobal) {
 578                         seterrmsg("cannot nest global commands");
 579                         return ERR;
 580                 } else if (check_addr_range(1, addr_last) < 0)
 581                         return ERR;
 582                 else if (build_active_list(c == 'g' || c == 'G') < 0)
 583                         return ERR;
 584                 else if ((n = (c == 'G' || c == 'V')))
 585                         GET_COMMAND_SUFFIX();
 586                 isglobal++;
 587                 if (exec_global(n, gflag) < 0)
 588                         return ERR;
 589                 break;
 590         case 'h':
 591                 if (addr_cnt > 0) {
 592                         seterrmsg("unexpected address");
 593                         return ERR;
 594                 }
 595                 GET_COMMAND_SUFFIX();
 596                 if (*errmsg) fprintf(stderr, "%s\n", errmsg);
 597                 break;
 598         case 'H':
 599                 if (addr_cnt > 0) {
 600                         seterrmsg("unexpected address");
 601                         return ERR;
 602                 }
 603                 GET_COMMAND_SUFFIX();
 604                 if ((garrulous = 1 - garrulous) && *errmsg)
 605                         fprintf(stderr, "%s\n", errmsg);
 606                 break;
 607         case 'i':
 608                 if (second_addr == 0) {
 609                         seterrmsg("invalid address");
 610                         return ERR;
 611                 }
 612                 GET_COMMAND_SUFFIX();
 613                 if (!isglobal) clear_undo_stack();
 614                 if (append_lines(second_addr - 1) < 0)
 615                         return ERR;
 616                 break;
 617         case 'j':
 618                 if (check_addr_range(current_addr, current_addr + 1) < 0)
 619                         return ERR;
 620                 GET_COMMAND_SUFFIX();
 621                 if (!isglobal) clear_undo_stack();
 622                 if (first_addr != second_addr &&
 623                     join_lines(first_addr, second_addr) < 0)
 624                         return ERR;
 625                 break;
 626         case 'k':
 627                 c = *ibufp++;
 628                 if (second_addr == 0) {
 629                         seterrmsg("invalid address");
 630                         return ERR;
 631                 }
 632                 GET_COMMAND_SUFFIX();
 633                 if (mark_line_node(get_addressed_line_node(second_addr), c) < 0)
 634                         return ERR;
 635                 break;
 636         case 'l':
 637                 if (check_addr_range(current_addr, current_addr) < 0)
 638                         return ERR;
 639                 GET_COMMAND_SUFFIX();
 640                 if (display_lines(first_addr, second_addr, gflag | GLS) < 0)
 641                         return ERR;
 642                 gflag = 0;
 643                 break;
 644         case 'm':
 645                 if (check_addr_range(current_addr, current_addr) < 0)
 646                         return ERR;
 647                 GET_THIRD_ADDR(addr);
 648                 if (first_addr <= addr && addr < second_addr) {
 649                         seterrmsg("invalid destination");
 650                         return ERR;
 651                 }
 652                 GET_COMMAND_SUFFIX();
 653                 if (!isglobal) clear_undo_stack();
 654                 if (move_lines(addr) < 0)
 655                         return ERR;
 656                 break;
 657         case 'n':
 658                 if (check_addr_range(current_addr, current_addr) < 0)
 659                         return ERR;
 660                 GET_COMMAND_SUFFIX();
 661                 if (display_lines(first_addr, second_addr, gflag | GNP) < 0)
 662                         return ERR;
 663                 gflag = 0;
 664                 break;
 665         case 'p':
 666                 if (check_addr_range(current_addr, current_addr) < 0)
 667                         return ERR;
 668                 GET_COMMAND_SUFFIX();
 669                 if (display_lines(first_addr, second_addr, gflag | GPR) < 0)
 670                         return ERR;
 671                 gflag = 0;
 672                 break;
 673         case 'P':
 674                 if (addr_cnt > 0) {
 675                         seterrmsg("unexpected address");
 676                         return ERR;
 677                 }
 678                 GET_COMMAND_SUFFIX();
 679                 prompt = prompt ? NULL : optarg ? optarg : dps;
 680                 break;
 681         case 'q':
 682         case 'Q':
 683                 if (addr_cnt > 0) {
 684                         seterrmsg("unexpected address");
 685                         return ERR;
 686                 }
 687                 GET_COMMAND_SUFFIX();
 688                 gflag =  (modified && !scripted && c == 'q') ? EMOD : EOF;
 689                 break;
 690         case 'r':
 691                 if (!isspace(*ibufp)) {
 692                         seterrmsg("unexpected command suffix");
 693                         return ERR;
 694                 } else if (addr_cnt == 0)
 695                         second_addr = addr_last;
 696                 if ((fnp = get_filename()) == NULL)
 697                         return ERR;
 698                 GET_COMMAND_SUFFIX();
 699                 if (!isglobal) clear_undo_stack();
 700                 if (*old_filename == '\0' && *fnp != '!')
 701                         strlcpy(old_filename, fnp, sizeof old_filename);
 702 #ifdef BACKWARDS
 703                 if (*fnp == '\0' && *old_filename == '\0') {
 704                         seterrmsg("no current filename");
 705                         return ERR;
 706                 }
 707 #endif
 708                 if ((addr = read_file(*fnp ? fnp : old_filename,
 709                     second_addr)) < 0)
 710                         return ERR;
 711                 else if (addr && addr != addr_last)
 712                         modified = 1;
 713                 break;
 714         case 's':
 715                 do {
 716                         switch (*ibufp) {
 717                         case '\n':
 718                                 sflags |=SGF;
 719                                 break;
 720                         case 'g':
 721                                 sflags |= SGG;
 722                                 ibufp++;
 723                                 break;
 724                         case 'p':
 725                                 sflags |= SGP;
 726                                 ibufp++;
 727                                 break;
 728                         case 'r':
 729                                 sflags |= SGR;
 730                                 ibufp++;
 731                                 break;
 732                         case '0': case '1': case '2': case '3': case '4':
 733                         case '5': case '6': case '7': case '8': case '9':
 734                                 STRTOI(sgnum, ibufp);
 735                                 sflags |= SGF;
 736                                 sgflag &= ~GSG;         /* override GSG */
 737                                 break;
 738                         default:
 739                                 if (sflags) {
 740                                         seterrmsg("invalid command suffix");
 741                                         return ERR;
 742                                 }
 743                         }
 744                 } while (sflags && *ibufp != '\n');
 745                 if (sflags && !pat) {
 746                         seterrmsg("no previous substitution");
 747                         return ERR;
 748                 } else if (sflags & SGG)
 749                         sgnum = 0;              /* override numeric arg */
 750                 if (*ibufp != '\n' && *(ibufp + 1) == '\n') {
 751                         seterrmsg("invalid pattern delimiter");
 752                         return ERR;
 753                 }
 754                 tpat = pat;
 755                 SPL1();
 756                 if ((!sflags || (sflags & SGR)) &&
 757                     (tpat = get_compiled_pattern()) == NULL) {
 758                         SPL0();
 759                         return ERR;
 760                 } else if (tpat != pat) {
 761                         if (pat) {
 762                                 regfree(pat);
 763                                 free(pat);
 764                         }
 765                         pat = tpat;
 766                         patlock = 1;            /* reserve pattern */
 767                 }
 768                 SPL0();
 769                 if (!sflags && extract_subst_tail(&sgflag, &sgnum) < 0)
 770                         return ERR;
 771                 else if (isglobal)
 772                         sgflag |= GLB;
 773                 else
 774                         sgflag &= ~GLB;
 775                 if (sflags & SGG)
 776                         sgflag ^= GSG;
 777                 if (sflags & SGP) {
 778                         sgflag ^= GPR;
 779                         sgflag &= ~(GLS | GNP);
 780                 }
 781                 do {
 782                         switch (*ibufp) {
 783                         case 'p':
 784                                 sgflag |= GPR;
 785                                 ibufp++;
 786                                 break;
 787                         case 'l':
 788                                 sgflag |= GLS;
 789                                 ibufp++;
 790                                 break;
 791                         case 'n':
 792                                 sgflag |= GNP;
 793                                 ibufp++;
 794                                 break;
 795                         default:
 796                                 n++;
 797                         }
 798                 } while (!n);
 799                 if (check_addr_range(current_addr, current_addr) < 0)
 800                         return ERR;
 801                 GET_COMMAND_SUFFIX();
 802                 if (!isglobal) clear_undo_stack();
 803                 if (search_and_replace(pat, sgflag, sgnum) < 0)
 804                         return ERR;
 805                 break;
 806         case 't':
 807                 if (check_addr_range(current_addr, current_addr) < 0)
 808                         return ERR;
 809                 GET_THIRD_ADDR(addr);
 810                 GET_COMMAND_SUFFIX();
 811                 if (!isglobal) clear_undo_stack();
 812                 if (copy_lines(addr) < 0)
 813                         return ERR;
 814                 break;
 815         case 'u':
 816                 if (addr_cnt > 0) {
 817                         seterrmsg("unexpected address");
 818                         return ERR;
 819                 }
 820                 GET_COMMAND_SUFFIX();
 821                 if (pop_undo_stack() < 0)
 822                         return ERR;
 823                 break;
 824         case 'w':
 825         case 'W':
 826                 if ((n = *ibufp) == 'q' || n == 'Q') {
 827                         gflag = EOF;
 828                         ibufp++;
 829                 }
 830                 if (!isspace(*ibufp)) {
 831                         seterrmsg("unexpected command suffix");
 832                         return ERR;
 833                 } else if ((fnp = get_filename()) == NULL)
 834                         return ERR;
 835                 if (addr_cnt == 0 && !addr_last)
 836                         first_addr = second_addr = 0;
 837                 else if (check_addr_range(1, addr_last) < 0)
 838                         return ERR;
 839                 GET_COMMAND_SUFFIX();
 840                 if (*old_filename == '\0' && *fnp != '!')
 841                         strlcpy(old_filename, fnp, sizeof old_filename);
 842 #ifdef BACKWARDS
 843                 if (*fnp == '\0' && *old_filename == '\0') {
 844                         seterrmsg("no current filename");
 845                         return ERR;
 846                 }
 847 #endif
 848                 if ((addr = write_file(*fnp ? fnp : old_filename,
 849                     (c == 'W') ? "a" : "w", first_addr, second_addr)) < 0)
 850                         return ERR;
 851                 else if (addr == addr_last)
 852                         modified = 0;
 853                 else if (modified && !scripted && n == 'q')
 854                         gflag = EMOD;
 855                 break;
 856         case 'x':
 857                 if (addr_cnt > 0) {
 858                         seterrmsg("unexpected address");
 859                         return ERR;
 860                 }
 861                 GET_COMMAND_SUFFIX();
 862 #ifdef DES
 863                 des = get_keyword();
 864 #else
 865                 seterrmsg("crypt unavailable");
 866                 return ERR;
 867 #endif
 868                 break;
 869         case 'z':
 870                 first_addr = 1;
 871 #ifdef BACKWARDS
 872                 if (check_addr_range(first_addr, current_addr + 1) < 0)
 873 #else
 874                 if (check_addr_range(first_addr, current_addr + !isglobal) < 0)
 875 #endif
 876                         return ERR;
 877                 else if ('0' < *ibufp && *ibufp <= '9')
 878                         STRTOI(rows, ibufp);
 879                 GET_COMMAND_SUFFIX();
 880                 if (display_lines(second_addr, min(addr_last,
 881                     second_addr + rows), gflag) < 0)
 882                         return ERR;
 883                 gflag = 0;
 884                 break;
 885         case '=':
 886                 GET_COMMAND_SUFFIX();
 887                 printf("%d\n", addr_cnt ? second_addr : addr_last);
 888                 break;
 889         case '!':
 890                 if (addr_cnt > 0) {
 891                         seterrmsg("unexpected address");
 892                         return ERR;
 893                 } else if ((sflags = get_shell_command()) < 0)
 894                         return ERR;
 895                 GET_COMMAND_SUFFIX();
 896                 if (sflags) printf("%s\n", shcmd + 1);
 897                 system(shcmd + 1);
 898                 if (!scripted) printf("!\n");
 899                 break;
 900         case '\n':
 901                 first_addr = 1;
 902 #ifdef BACKWARDS
 903                 if (check_addr_range(first_addr, current_addr + 1) < 0
 904 #else
 905                 if (check_addr_range(first_addr, current_addr + !isglobal) < 0
 906 #endif
 907                  || display_lines(second_addr, second_addr, 0) < 0)
 908                         return ERR;
 909                 break;
 910         default:
 911                 seterrmsg("unknown command");
 912                 return ERR;
 913         }
 914         return gflag;
 915 }
 916
 917
 918 /* check_addr_range: return status of address range check */
 919 int
 920 check_addr_range(int n, int m)
 921 {
 922         if (addr_cnt == 0) {
 923                 first_addr = n;
 924                 second_addr = m;
 925         }
 926         if (first_addr > second_addr || 1 > first_addr ||
 927             second_addr > addr_last) {
 928                 seterrmsg("invalid address");
 929                 return ERR;
 930         }
 931         return 0;
 932 }
 933
 934
 935 /* get_matching_node_addr: return the address of the next line matching a
 936    pattern in a given direction.  wrap around begin/end of editor buffer if
 937    necessary */
 938 int
 939 get_matching_node_addr(pattern_t *pat, int dir)
 940 {
 941         char *s;
 942         int n = current_addr;
 943         line_t *lp;
 944
 945         if (!pat) return ERR;
 946         do {
 947                 if ((n = dir ? INC_MOD(n, addr_last) : DEC_MOD(n, addr_last))) {
 948                         lp = get_addressed_line_node(n);
 949                         if ((s = get_sbuf_line(lp)) == NULL)
 950                                 return ERR;
 951                         if (isbinary)
 952                                 NUL_TO_NEWLINE(s, lp->len);
 953                         if (!regexec(pat, s, 0, NULL, 0))
 954                                 return n;
 955                 }
 956         } while (n != current_addr);
 957         seterrmsg("no match");
 958         return  ERR;
 959 }
 960
 961
 962 /* get_filename: return pointer to copy of filename in the command buffer */
 963 char *
 964 get_filename(void)
 965 {
 966         static char *file = NULL;
 967         static int filesz = 0;
 968         int n;
 969
 970         if (*ibufp != '\n') {
 971                 SKIP_BLANKS();
 972                 if (*ibufp == '\n') {
 973                         seterrmsg("invalid filename");
 974                         return NULL;
 975                 } else if ((ibufp = get_extended_line(&n, 1)) == NULL)
 976                         return NULL;
 977                 else if (*ibufp == '!') {
 978                         ibufp++;
 979                         if ((n = get_shell_command()) < 0)
 980                                 return NULL;
 981                         if (n) printf("%s\n", shcmd + 1);
 982                         return shcmd;
 983                 } else if (n >= MAXPATHLEN) {
 984                         seterrmsg("filename too long");
 985                         return  NULL;
 986                 }
 987         }
 988 #ifndef BACKWARDS
 989         else if (*old_filename == '\0') {
 990                 seterrmsg("no current filename");
 991                 return  NULL;
 992         }
 993 #endif
 994         REALLOC(file, filesz, MAXPATHLEN, NULL);
 995         for (n = 0; *ibufp != '\n';)
 996                 file[n++] = *ibufp++;
 997         file[n] = '\0';
 998         return is_legal_filename(file) ? file : NULL;
 999 }
1000
1001
1002 /* get_shell_command: read a shell command from stdin; return substitution
1003    status */
1004 int
1005 get_shell_command(void)
1006 {
1007         static char *buf = NULL;
1008         static int n = 0;
1009
1010         char *s;                        /* substitution char pointer */
1011         int i = 0;
1012         int j = 0;
1013
1014         if (red) {
1015                 seterrmsg("shell access restricted");
1016                 return ERR;
1017         } else if ((s = ibufp = get_extended_line(&j, 1)) == NULL)
1018                 return ERR;
1019         REALLOC(buf, n, j + 1, ERR);
1020         buf[i++] = '!';                 /* prefix command w/ bang */
1021         while (*ibufp != '\n')
1022                 switch (*ibufp) {
1023                 default:
1024                         REALLOC(buf, n, i + 2, ERR);
1025                         buf[i++] = *ibufp;
1026                         if (*ibufp++ == '\\')
1027                                 buf[i++] = *ibufp++;
1028                         break;
1029                 case '!':
1030                         if (s != ibufp) {
1031                                 REALLOC(buf, n, i + 1, ERR);
1032                                 buf[i++] = *ibufp++;
1033                         }
1034 #ifdef BACKWARDS
1035                         else if (shcmd == NULL || *(shcmd + 1) == '\0')
1036 #else
1037                         else if (shcmd == NULL)
1038 #endif
1039                         {
1040                                 seterrmsg("no previous command");
1041                                 return ERR;
1042                         } else {
1043                                 REALLOC(buf, n, i + shcmdi, ERR);
1044                                 for (s = shcmd + 1; s < shcmd + shcmdi;)
1045                                         buf[i++] = *s++;
1046                                 s = ibufp++;
1047                         }
1048                         break;
1049                 case '%':
1050                         if (*old_filename  == '\0') {
1051                                 seterrmsg("no current filename");
1052                                 return ERR;
1053                         }
1054                         j = strlen(s = strip_escapes(old_filename));
1055                         REALLOC(buf, n, i + j, ERR);
1056                         while (j--)
1057                                 buf[i++] = *s++;
1058                         s = ibufp++;
1059                         break;
1060                 }
1061         REALLOC(shcmd, shcmdsz, i + 1, ERR);
1062         memcpy(shcmd, buf, i);
1063         shcmd[shcmdi = i] = '\0';
1064         return *s == '!' || *s == '%';
1065 }
1066
1067
1068 /* append_lines: insert text from stdin to after line n; stop when either a
1069    single period is read or EOF; return status */
1070 int
1071 append_lines(int n)
1072 {
1073         int l;
1074         char *lp = ibuf;
1075         char *eot;
1076         undo_t *up = NULL;
1077
1078         for (current_addr = n;;) {
1079                 if (!isglobal) {
1080                         if ((l = get_tty_line()) < 0)
1081                                 return ERR;
1082                         else if (l == 0 || ibuf[l - 1] != '\n') {
1083                                 clearerr(stdin);
1084                                 return  l ? EOF : 0;
1085                         }
1086                         lp = ibuf;
1087                 } else if (*(lp = ibufp) == '\0')
1088                         return 0;
1089                 else {
1090                         while (*ibufp++ != '\n')
1091                                 ;
1092                         l = ibufp - lp;
1093                 }
1094                 if (l == 2 && lp[0] == '.' && lp[1] == '\n') {
1095                         return 0;
1096                 }
1097                 eot = lp + l;
1098                 SPL1();
1099                 do {
1100                         if ((lp = put_sbuf_line(lp)) == NULL) {
1101                                 SPL0();
1102                                 return ERR;
1103                         } else if (up)
1104                                 up->t = get_addressed_line_node(current_addr);
1105                         else if ((up = push_undo_stack(UADD, current_addr,
1106                             current_addr)) == NULL) {
1107                                 SPL0();
1108                                 return ERR;
1109                         }
1110                 } while (lp != eot);
1111                 modified = 1;
1112                 SPL0();
1113         }
1114         /* NOTREACHED */
1115 }
1116
1117
1118 /* join_lines: replace a range of lines with the joined text of those lines */
1119 int
1120 join_lines(int from, int to)
1121 {
1122         static char *buf = NULL;
1123         static int n;
1124
1125         char *s;
1126         int size = 0;
1127         line_t *bp, *ep;
1128
1129         ep = get_addressed_line_node(INC_MOD(to, addr_last));
1130         bp = get_addressed_line_node(from);
1131         for (; bp != ep; bp = bp->q_forw) {
1132                 if ((s = get_sbuf_line(bp)) == NULL)
1133                         return ERR;
1134                 REALLOC(buf, n, size + bp->len, ERR);
1135                 memcpy(buf + size, s, bp->len);
1136                 size += bp->len;
1137         }
1138         REALLOC(buf, n, size + 2, ERR);
1139         memcpy(buf + size, "\n", 2);
1140         if (delete_lines(from, to) < 0)
1141                 return ERR;
1142         current_addr = from - 1;
1143         SPL1();
1144         if (put_sbuf_line(buf) == NULL ||
1145             push_undo_stack(UADD, current_addr, current_addr) == NULL) {
1146                 SPL0();
1147                 return ERR;
1148         }
1149         modified = 1;
1150         SPL0();
1151         return 0;
1152 }
1153
1154
1155 /* move_lines: move a range of lines */
1156 int
1157 move_lines(int addr)
1158 {
1159         line_t *b1, *a1, *b2, *a2;
1160         int n = INC_MOD(second_addr, addr_last);
1161         int p = first_addr - 1;
1162         int done = (addr == first_addr - 1 || addr == second_addr);
1163
1164         SPL1();
1165         if (done) {
1166                 a2 = get_addressed_line_node(n);
1167                 b2 = get_addressed_line_node(p);
1168                 current_addr = second_addr;
1169         } else if (push_undo_stack(UMOV, p, n) == NULL ||
1170             push_undo_stack(UMOV, addr, INC_MOD(addr, addr_last)) == NULL) {
1171                 SPL0();
1172                 return ERR;
1173         } else {
1174                 a1 = get_addressed_line_node(n);
1175                 if (addr < first_addr) {
1176                         b1 = get_addressed_line_node(p);
1177                         b2 = get_addressed_line_node(addr);
1178                                         /* this get_addressed_line_node last! */
1179                 } else {
1180                         b2 = get_addressed_line_node(addr);
1181                         b1 = get_addressed_line_node(p);
1182                                         /* this get_addressed_line_node last! */
1183                 }
1184                 a2 = b2->q_forw;
1185                 REQUE(b2, b1->q_forw);
1186                 REQUE(a1->q_back, a2);
1187                 REQUE(b1, a1);
1188                 current_addr = addr + ((addr < first_addr) ?
1189                     second_addr - first_addr + 1 : 0);
1190         }
1191         if (isglobal)
1192                 unset_active_nodes(b2->q_forw, a2);
1193         modified = 1;
1194         SPL0();
1195         return 0;
1196 }
1197
1198
1199 /* copy_lines: copy a range of lines; return status */
1200 int
1201 copy_lines(int addr)
1202 {
1203         line_t *lp, *np = get_addressed_line_node(first_addr);
1204         undo_t *up = NULL;
1205         int n = second_addr - first_addr + 1;
1206         int m = 0;
1207
1208         current_addr = addr;
1209         if (first_addr <= addr && addr < second_addr) {
1210                 n =  addr - first_addr + 1;
1211                 m = second_addr - addr;
1212         }
1213         for (; n > 0; n=m, m=0, np = get_addressed_line_node(current_addr + 1))
1214                 for (; n-- > 0; np = np->q_forw) {
1215                         SPL1();
1216                         if ((lp = dup_line_node(np)) == NULL) {
1217                                 SPL0();
1218                                 return ERR;
1219                         }
1220                         add_line_node(lp);
1221                         if (up)
1222                                 up->t = lp;
1223                         else if ((up = push_undo_stack(UADD, current_addr,
1224                             current_addr)) == NULL) {
1225                                 SPL0();
1226                                 return ERR;
1227                         }
1228                         modified = 1;
1229                         SPL0();
1230                 }
1231         return 0;
1232 }
1233
1234
1235 /* delete_lines: delete a range of lines */
1236 int
1237 delete_lines(int from, int to)
1238 {
1239         line_t *n, *p;
1240
1241         SPL1();
1242         if (push_undo_stack(UDEL, from, to) == NULL) {
1243                 SPL0();
1244                 return ERR;
1245         }
1246         n = get_addressed_line_node(INC_MOD(to, addr_last));
1247         p = get_addressed_line_node(from - 1);
1248                                         /* this get_addressed_line_node last! */
1249         if (isglobal)
1250                 unset_active_nodes(p->q_forw, n);
1251         REQUE(p, n);
1252         addr_last -= to - from + 1;
1253         current_addr = from - 1;
1254         modified = 1;
1255         SPL0();
1256         return 0;
1257 }
1258
1259
1260 /* display_lines: print a range of lines to stdout */
1261 int
1262 display_lines(int from, int to, int gflag)
1263 {
1264         line_t *bp;
1265         line_t *ep;
1266         char *s;
1267
1268         if (!from) {
1269                 seterrmsg("invalid address");
1270                 return ERR;
1271         }
1272         ep = get_addressed_line_node(INC_MOD(to, addr_last));
1273         bp = get_addressed_line_node(from);
1274         for (; bp != ep; bp = bp->q_forw) {
1275                 if ((s = get_sbuf_line(bp)) == NULL)
1276                         return ERR;
1277                 if (put_tty_line(s, bp->len, current_addr = from++, gflag) < 0)
1278                         return ERR;
1279         }
1280         return 0;
1281 }
1282
1283
1284 #define MAXMARK 26                      /* max number of marks */
1285
1286 line_t  *mark[MAXMARK];                 /* line markers */
1287 int markno;                             /* line marker count */
1288
1289 /* mark_line_node: set a line node mark */
1290 int
1291 mark_line_node(line_t *lp, int n)
1292 {
1293         if (!islower(n)) {
1294                 seterrmsg("invalid mark character");
1295                 return ERR;
1296         } else if (mark[n - 'a'] == NULL)
1297                 markno++;
1298         mark[n - 'a'] = lp;
1299         return 0;
1300 }
1301
1302
1303 /* get_marked_node_addr: return address of a marked line */
1304 int
1305 get_marked_node_addr(int n)
1306 {
1307         if (!islower(n)) {
1308                 seterrmsg("invalid mark character");
1309                 return ERR;
1310         }
1311         return get_line_node_addr(mark[n - 'a']);
1312 }
1313
1314
1315 /* unmark_line_node: clear line node mark */
1316 void
1317 unmark_line_node(line_t *lp)
1318 {
1319         int i;
1320
1321         for (i = 0; markno && i < MAXMARK; i++)
1322                 if (mark[i] == lp) {
1323                         mark[i] = NULL;
1324                         markno--;
1325                 }
1326 }
1327
1328
1329 /* dup_line_node: return a pointer to a copy of a line node */
1330 line_t *
1331 dup_line_node(line_t *lp)
1332 {
1333         line_t *np;
1334
1335         if ((np = (line_t *) malloc(sizeof(line_t))) == NULL) {
1336                 perror(NULL);
1337                 seterrmsg("out of memory");
1338                 return NULL;
1339         }
1340         np->seek = lp->seek;
1341         np->len = lp->len;
1342         return np;
1343 }
1344
1345
1346 /* has_trailing_escape:  return the parity of escapes preceding a character
1347    in a string */
1348 int
1349 has_trailing_escape(char *s, char *t)
1350 {
1351     return (s == t || *(t - 1) != '\\') ? 0 : !has_trailing_escape(s, t - 1);
1352 }
1353
1354
1355 /* strip_escapes: return copy of escaped string of at most length MAXPATHLEN */
1356 char *
1357 strip_escapes(char *s)
1358 {
1359         static char *file = NULL;
1360         static int filesz = 0;
1361
1362         int i = 0;
1363
1364         REALLOC(file, filesz, MAXPATHLEN, NULL);
1365         /* assert: no trailing escape */
1366         while ((file[i++] = (*s == '\\') ? *++s : *s) != '\0' &&
1367                i < MAXPATHLEN-1)
1368                 s++;
1369         file[MAXPATHLEN-1] = '\0';
1370         return file;
1371 }
1372
1373
1374 void
1375 signal_hup(int signo)
1376 {
1377         int save_errno = errno;
1378
1379         if (mutex)
1380                 sigflags |= (1 << (signo - 1));
1381         else
1382                 handle_hup(signo);
1383         errno = save_errno;
1384 }
1385
1386
1387 void
1388 signal_int(int signo)
1389 {
1390         int save_errno = errno;
1391
1392         if (mutex)
1393                 sigflags |= (1 << (signo - 1));
1394         else
1395                 handle_int(signo);
1396         errno = save_errno;
1397 }
1398
1399
1400 void
1401 handle_hup(int signo)
1402 {
1403         char hup[MAXPATHLEN];
1404
1405         if (!sigactive)
1406                 quit(1);
1407         sigflags &= ~(1 << (signo - 1));
1408         /* XXX signal race */
1409         if (addr_last && write_file("ed.hup", "w", 1, addr_last) < 0 &&
1410             home != NULL && home[0] == '/') {
1411                 if (strlcpy(hup, home, sizeof(hup)) < sizeof(hup) &&
1412                     strlcat(hup, "/ed.hup", sizeof(hup)) < sizeof(hup))
1413                         write_file(hup, "w", 1, addr_last);
1414         }
1415         _exit(2);
1416 }
1417
1418
1419 void
1420 handle_int(int signo)
1421 {
1422         if (!sigactive)
1423                 _exit(1);
1424         sigflags &= ~(1 << (signo - 1));
1425 #ifdef _POSIX_SOURCE
1426         siglongjmp(env, -1);
1427 #else
1428         longjmp(env, -1);
1429 #endif
1430 }
1431
1432
1433 void
1434 handle_winch(int signo)
1435 {
1436         int save_errno = errno;
1437         struct winsize ws;              /* window size structure */
1438
1439         sigflags &= ~(1 << (signo - 1));
1440         if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) >= 0) {
1441                 if (ws.ws_row > 2)
1442                         rows = ws.ws_row - 2;
1443                 if (ws.ws_col > 8)
1444                         cols = ws.ws_col - 8;
1445         }
1446         errno = save_errno;
1447 }
1448
1449
1450 /* is_legal_filename: return a legal filename */
1451 int
1452 is_legal_filename(char *s)
1453 {
1454         if (red && (*s == '!' || !strcmp(s, "..") || strchr(s, '/'))) {
1455                 seterrmsg("shell access restricted");
1456                 return 0;
1457         }
1458         return 1;
1459 }