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  * @(#) Copyright (c) 1993 Andrew Moore, Talke Studio. All rights reserved.
  29  * @(#)main.c,v 1.1 1994/02/01 00:34:42 alm Exp
  30  * $FreeBSD: src/bin/ed/main.c,v 1.14.2.4 2001/08/01 02:36:03 obrien Exp $
  31  * $DragonFly: src/bin/ed/main.c,v 1.2 2003/06/17 04:22:49 dillon Exp $
  32  */
  33
  34 /*
  35  * CREDITS
  36  *
  37  *      This program is based on the editor algorithm described in
  38  *      Brian W. Kernighan and P. J. Plauger's book "Software Tools
  39  *      in Pascal," Addison-Wesley, 1981.
  40  *
  41  *      The buffering algorithm is attributed to Rodney Ruddock of
  42  *      the University of Guelph, Guelph, Ontario.
  43  *
  44  *      The cbc.c encryption code is adapted from
  45  *      the bdes program by Matt Bishop of Dartmouth College,
  46  *      Hanover, NH.
  47  *
  48  */
  49
  50 #include <sys/types.h>
  51
  52 #include <sys/ioctl.h>
  53 #include <sys/wait.h>
  54 #include <ctype.h>
  55 #include <locale.h>
  56 #include <pwd.h>
  57 #include <setjmp.h>
  58
  59 #include "ed.h"
  60
  61
  62 #ifdef _POSIX_SOURCE
  63 sigjmp_buf env;
  64 #else
  65 jmp_buf env;
  66 #endif
  67
  68 /* static buffers */
  69 char stdinbuf[1];               /* stdin buffer */
  70 char *shcmd;                    /* shell command buffer */
  71 int shcmdsz;                    /* shell command buffer size */
  72 int shcmdi;                     /* shell command buffer index */
  73 char *ibuf;                     /* ed command-line buffer */
  74 int ibufsz;                     /* ed command-line buffer size */
  75 char *ibufp;                    /* pointer to ed command-line buffer */
  76
  77 /* global flags */
  78 int des = 0;                    /* if set, use crypt(3) for i/o */
  79 int garrulous = 0;              /* if set, print all error messages */
  80 int isbinary;                   /* if set, buffer contains ASCII NULs */
  81 int isglobal;                   /* if set, doing a global command */
  82 int modified;                   /* if set, buffer modified since last write */
  83 int mutex = 0;                  /* if set, signals set "sigflags" */
  84 int red = 0;                    /* if set, restrict shell/directory access */
  85 int scripted = 0;               /* if set, suppress diagnostics */
  86 int sigflags = 0;               /* if set, signals received while mutex set */
  87 int sigactive = 0;              /* if set, signal handlers are enabled */
  88
  89 char old_filename[PATH_MAX] = "";       /* default filename */
  90 long current_addr;              /* current address in editor buffer */
  91 long 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 const char usage[] = "usage: %s [-] [-sx] [-p string] [name]\n";
  97
  98 /* ed: line editor */
  99 int
 100 main(argc, argv)
 101         int argc;
 102         char **argv;
 103 {
 104         int c, n;
 105         long status = 0;
 106 #if __GNUC__
 107         /* Avoid longjmp clobbering */
 108         (void) &argc;
 109         (void) &argv;
 110 #endif
 111
 112         (void)setlocale(LC_ALL, "");
 113
 114         red = (n = strlen(argv[0])) > 2 && argv[0][n - 3] == 'r';
 115 top:
 116         while ((c = getopt(argc, argv, "p:sx")) != -1)
 117                 switch(c) {
 118                 case 'p':                               /* set prompt */
 119                         prompt = optarg;
 120                         break;
 121                 case 's':                               /* run script */
 122                         scripted = 1;
 123                         break;
 124                 case 'x':                               /* use crypt */
 125 #ifdef DES
 126                         des = get_keyword();
 127 #else
 128                         fprintf(stderr, "crypt unavailable\n?\n");
 129 #endif
 130                         break;
 131
 132                 default:
 133                         fprintf(stderr, usage, argv[0]);
 134                         exit(1);
 135                 }
 136         argv += optind;
 137         argc -= optind;
 138         if (argc && **argv == '-') {
 139                 scripted = 1;
 140                 if (argc > 1) {
 141                         optind = 1;
 142                         goto top;
 143                 }
 144                 argv++;
 145                 argc--;
 146         }
 147         /* assert: reliable signals! */
 148 #ifdef SIGWINCH
 149         handle_winch(SIGWINCH);
 150         if (isatty(0)) signal(SIGWINCH, handle_winch);
 151 #endif
 152         signal(SIGHUP, signal_hup);
 153         signal(SIGQUIT, SIG_IGN);
 154         signal(SIGINT, signal_int);
 155 #ifdef _POSIX_SOURCE
 156         if ((status = sigsetjmp(env, 1)))
 157 #else
 158         if ((status = setjmp(env)))
 159 #endif
 160         {
 161                 fputs("\n?\n", stderr);
 162                 sprintf(errmsg, "interrupt");
 163         } else {
 164                 init_buffers();
 165                 sigactive = 1;                  /* enable signal handlers */
 166                 if (argc && **argv && is_legal_filename(*argv)) {
 167                         if (read_file(*argv, 0) < 0 && !isatty(0))
 168                                 quit(2);
 169                         else if (**argv != '!')
 170                                 if (strlcpy(old_filename, *argv, sizeof(old_filename))
 171                                     >= sizeof(old_filename))
 172                                         quit(2);
 173                 } else if (argc) {
 174                         fputs("?\n", stderr);
 175                         if (**argv == '\0')
 176                                 sprintf(errmsg, "invalid filename");
 177                         if (!isatty(0))
 178                                 quit(2);
 179                 }
 180         }
 181         for (;;) {
 182                 if (status < 0 && garrulous)
 183                         fprintf(stderr, "%s\n", errmsg);
 184                 if (prompt) {
 185                         printf("%s", prompt);
 186                         fflush(stdout);
 187                 }
 188                 if ((n = get_tty_line()) < 0) {
 189                         status = ERR;
 190                         continue;
 191                 } else if (n == 0) {
 192                         if (modified && !scripted) {
 193                                 fputs("?\n", stderr);
 194                                 sprintf(errmsg, "warning: file modified");
 195                                 if (!isatty(0)) {
 196                                         fprintf(stderr, garrulous ?
 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                         sprintf(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                         sprintf(errmsg, "warning: file modified");
 228                         if (!isatty(0)) {
 229                                 fprintf(stderr, garrulous ?
 230                                     "script, line %d: %s\n" :
 231                                     "", lineno, errmsg);
 232                                 quit(2);
 233                         }
 234                         break;
 235                 case FATAL:
 236                         if (!isatty(0))
 237                                 fprintf(stderr, garrulous ?
 238                                     "script, line %d: %s\n" : "",
 239                                     lineno, errmsg);
 240                         else
 241                                 fprintf(stderr, garrulous ? "%s\n" : "",
 242                                     errmsg);
 243                         quit(3);
 244                 default:
 245                         fputs("?\n", stderr);
 246                         if (!isatty(0)) {
 247                                 fprintf(stderr, garrulous ?
 248                                     "script, line %d: %s\n" : "",
 249                                     lineno, errmsg);
 250                                 quit(2);
 251                         }
 252                         break;
 253                 }
 254         }
 255         /*NOTREACHED*/
 256 }
 257
 258 long first_addr, second_addr, 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()
 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() \
 287         if (!first) { sprintf(errmsg, "invalid address"); return ERR; }
 288
 289 /*  next_addr: return the next line address in the command buffer */
 290 long
 291 next_addr()
 292 {
 293         char *hd;
 294         long addr = current_addr;
 295         long n;
 296         int first = 1;
 297         int c;
 298
 299         SKIP_BLANKS();
 300         for (hd = ibufp;; first = 0)
 301                 switch (c = *ibufp) {
 302                 case '+':
 303                 case '\t':
 304                 case ' ':
 305                 case '-':
 306                 case '^':
 307                         ibufp++;
 308                         SKIP_BLANKS();
 309                         if (isdigit((unsigned char)*ibufp)) {
 310                                 STRTOL(n, ibufp);
 311                                 addr += (c == '-' || c == '^') ? -n : n;
 312                         } else if (!isspace((unsigned char)c))
 313                                 addr += (c == '-' || c == '^') ? -1 : 1;
 314                         break;
 315                 case '0': case '1': case '2':
 316                 case '3': case '4': case '5':
 317                 case '6': case '7': case '8': case '9':
 318                         MUST_BE_FIRST();
 319                         STRTOL(addr, ibufp);
 320                         break;
 321                 case '.':
 322                 case '$':
 323                         MUST_BE_FIRST();
 324                         ibufp++;
 325                         addr = (c == '.') ? current_addr : addr_last;
 326                         break;
 327                 case '/':
 328                 case '?':
 329                         MUST_BE_FIRST();
 330                         if ((addr = get_matching_node_addr(
 331                             get_compiled_pattern(), c == '/')) < 0)
 332                                 return ERR;
 333                         else if (c == *ibufp)
 334                                 ibufp++;
 335                         break;
 336                 case '\'':
 337                         MUST_BE_FIRST();
 338                         ibufp++;
 339                         if ((addr = get_marked_node_addr(*ibufp++)) < 0)
 340                                 return ERR;
 341                         break;
 342                 case '%':
 343                 case ',':
 344                 case ';':
 345                         if (first) {
 346                                 ibufp++;
 347                                 addr_cnt++;
 348                                 second_addr = (c == ';') ? current_addr : 1;
 349                                 addr = addr_last;
 350                                 break;
 351                         }
 352                         /* FALL THROUGH */
 353                 default:
 354                         if (ibufp == hd)
 355                                 return EOF;
 356                         else if (addr < 0 || addr_last < addr) {
 357                                 sprintf(errmsg, "invalid address");
 358                                 return ERR;
 359                         } else
 360                                 return addr;
 361                 }
 362         /* NOTREACHED */
 363 }
 364
 365
 366 #ifdef BACKWARDS
 367 /* GET_THIRD_ADDR: get a legal address from the command buffer */
 368 #define GET_THIRD_ADDR(addr) \
 369 { \
 370         long ol1, ol2; \
 371 \
 372         ol1 = first_addr, ol2 = second_addr; \
 373         if (extract_addr_range() < 0) \
 374                 return ERR; \
 375         else if (addr_cnt == 0) { \
 376                 sprintf(errmsg, "destination expected"); \
 377                 return ERR; \
 378         } else if (second_addr < 0 || addr_last < second_addr) { \
 379                 sprintf(errmsg, "invalid address"); \
 380                 return ERR; \
 381         } \
 382         addr = second_addr; \
 383         first_addr = ol1, second_addr = ol2; \
 384 }
 385 #else   /* BACKWARDS */
 386 /* GET_THIRD_ADDR: get a legal address from the command buffer */
 387 #define GET_THIRD_ADDR(addr) \
 388 { \
 389         long ol1, ol2; \
 390 \
 391         ol1 = first_addr, ol2 = second_addr; \
 392         if (extract_addr_range() < 0) \
 393                 return ERR; \
 394         if (second_addr < 0 || addr_last < second_addr) { \
 395                 sprintf(errmsg, "invalid address"); \
 396                 return ERR; \
 397         } \
 398         addr = second_addr; \
 399         first_addr = ol1, second_addr = ol2; \
 400 }
 401 #endif
 402
 403
 404 /* GET_COMMAND_SUFFIX: verify the command suffix in the command buffer */
 405 #define GET_COMMAND_SUFFIX() { \
 406         int done = 0; \
 407         do { \
 408                 switch(*ibufp) { \
 409                 case 'p': \
 410                         gflag |= GPR, ibufp++; \
 411                         break; \
 412                 case 'l': \
 413                         gflag |= GLS, ibufp++; \
 414                         break; \
 415                 case 'n': \
 416                         gflag |= GNP, ibufp++; \
 417                         break; \
 418                 default: \
 419                         done++; \
 420                 } \
 421         } while (!done); \
 422         if (*ibufp++ != '\n') { \
 423                 sprintf(errmsg, "invalid command suffix"); \
 424                 return ERR; \
 425         } \
 426 }
 427
 428
 429 /* sflags */
 430 #define SGG 001         /* complement previous global substitute suffix */
 431 #define SGP 002         /* complement previous print suffix */
 432 #define SGR 004         /* use last regex instead of last pat */
 433 #define SGF 010         /* repeat last substitution */
 434
 435 int patlock = 0;        /* if set, pattern not freed by get_compiled_pattern() */
 436
 437 long rows = 22;         /* scroll length: ws_row - 2 */
 438
 439 /* exec_command: execute the next command in command buffer; return print
 440    request, if any */
 441 int
 442 exec_command()
 443 {
 444         extern long u_current_addr;
 445         extern long u_addr_last;
 446
 447         static pattern_t *pat = NULL;
 448         static int sgflag = 0;
 449         static long sgnum = 0;
 450
 451         pattern_t *tpat;
 452         char *fnp;
 453         int gflag = 0;
 454         int sflags = 0;
 455         long addr = 0;
 456         int n = 0;
 457         int c;
 458
 459         SKIP_BLANKS();
 460         switch(c = *ibufp++) {
 461         case 'a':
 462                 GET_COMMAND_SUFFIX();
 463                 if (!isglobal) clear_undo_stack();
 464                 if (append_lines(second_addr) < 0)
 465                         return ERR;
 466                 break;
 467         case 'c':
 468                 if (check_addr_range(current_addr, current_addr) < 0)
 469                         return ERR;
 470                 GET_COMMAND_SUFFIX();
 471                 if (!isglobal) clear_undo_stack();
 472                 if (delete_lines(first_addr, second_addr) < 0 ||
 473                     append_lines(current_addr) < 0)
 474                         return ERR;
 475                 break;
 476         case 'd':
 477                 if (check_addr_range(current_addr, current_addr) < 0)
 478                         return ERR;
 479                 GET_COMMAND_SUFFIX();
 480                 if (!isglobal) clear_undo_stack();
 481                 if (delete_lines(first_addr, second_addr) < 0)
 482                         return ERR;
 483                 else if ((addr = INC_MOD(current_addr, addr_last)) != 0)
 484                         current_addr = addr;
 485                 break;
 486         case 'e':
 487                 if (modified && !scripted)
 488                         return EMOD;
 489                 /* fall through */
 490         case 'E':
 491                 if (addr_cnt > 0) {
 492                         sprintf(errmsg, "unexpected address");
 493                         return ERR;
 494                 } else if (!isspace((unsigned char)*ibufp)) {
 495                         sprintf(errmsg, "unexpected command suffix");
 496                         return ERR;
 497                 } else if ((fnp = get_filename()) == NULL)
 498                         return ERR;
 499                 GET_COMMAND_SUFFIX();
 500                 if (delete_lines(1, addr_last) < 0)
 501                         return ERR;
 502                 clear_undo_stack();
 503                 if (close_sbuf() < 0)
 504                         return ERR;
 505                 else if (open_sbuf() < 0)
 506                         return FATAL;
 507                 if (*fnp && *fnp != '!') strcpy(old_filename, fnp);
 508 #ifdef BACKWARDS
 509                 if (*fnp == '\0' && *old_filename == '\0') {
 510                         sprintf(errmsg, "no current filename");
 511                         return ERR;
 512                 }
 513 #endif
 514                 if (read_file(*fnp ? fnp : old_filename, 0) < 0)
 515                         return ERR;
 516                 clear_undo_stack();
 517                 modified = 0;
 518                 u_current_addr = u_addr_last = -1;
 519                 break;
 520         case 'f':
 521                 if (addr_cnt > 0) {
 522                         sprintf(errmsg, "unexpected address");
 523                         return ERR;
 524                 } else if (!isspace((unsigned char)*ibufp)) {
 525                         sprintf(errmsg, "unexpected command suffix");
 526                         return ERR;
 527                 } else if ((fnp = get_filename()) == NULL)
 528                         return ERR;
 529                 else if (*fnp == '!') {
 530                         sprintf(errmsg, "invalid redirection");
 531                         return ERR;
 532                 }
 533                 GET_COMMAND_SUFFIX();
 534                 if (*fnp) strcpy(old_filename, fnp);
 535                 printf("%s\n", strip_escapes(old_filename));
 536                 break;
 537         case 'g':
 538         case 'v':
 539         case 'G':
 540         case 'V':
 541                 if (isglobal) {
 542                         sprintf(errmsg, "cannot nest global commands");
 543                         return ERR;
 544                 } else if (check_addr_range(1, addr_last) < 0)
 545                         return ERR;
 546                 else if (build_active_list(c == 'g' || c == 'G') < 0)
 547                         return ERR;
 548                 else if ((n = (c == 'G' || c == 'V')))
 549                         GET_COMMAND_SUFFIX();
 550                 isglobal++;
 551                 if (exec_global(n, gflag) < 0)
 552                         return ERR;
 553                 break;
 554         case 'h':
 555                 if (addr_cnt > 0) {
 556                         sprintf(errmsg, "unexpected address");
 557                         return ERR;
 558                 }
 559                 GET_COMMAND_SUFFIX();
 560                 if (*errmsg) fprintf(stderr, "%s\n", errmsg);
 561                 break;
 562         case 'H':
 563                 if (addr_cnt > 0) {
 564                         sprintf(errmsg, "unexpected address");
 565                         return ERR;
 566                 }
 567                 GET_COMMAND_SUFFIX();
 568                 if ((garrulous = 1 - garrulous) && *errmsg)
 569                         fprintf(stderr, "%s\n", errmsg);
 570                 break;
 571         case 'i':
 572                 if (second_addr == 0) {
 573                         sprintf(errmsg, "invalid address");
 574                         return ERR;
 575                 }
 576                 GET_COMMAND_SUFFIX();
 577                 if (!isglobal) clear_undo_stack();
 578                 if (append_lines(second_addr - 1) < 0)
 579                         return ERR;
 580                 break;
 581         case 'j':
 582                 if (check_addr_range(current_addr, current_addr + 1) < 0)
 583                         return ERR;
 584                 GET_COMMAND_SUFFIX();
 585                 if (!isglobal) clear_undo_stack();
 586                 if (first_addr != second_addr &&
 587                     join_lines(first_addr, second_addr) < 0)
 588                         return ERR;
 589                 break;
 590         case 'k':
 591                 c = *ibufp++;
 592                 if (second_addr == 0) {
 593                         sprintf(errmsg, "invalid address");
 594                         return ERR;
 595                 }
 596                 GET_COMMAND_SUFFIX();
 597                 if (mark_line_node(get_addressed_line_node(second_addr), c) < 0)
 598                         return ERR;
 599                 break;
 600         case 'l':
 601                 if (check_addr_range(current_addr, current_addr) < 0)
 602                         return ERR;
 603                 GET_COMMAND_SUFFIX();
 604                 if (display_lines(first_addr, second_addr, gflag | GLS) < 0)
 605                         return ERR;
 606                 gflag = 0;
 607                 break;
 608         case 'm':
 609                 if (check_addr_range(current_addr, current_addr) < 0)
 610                         return ERR;
 611                 GET_THIRD_ADDR(addr);
 612                 if (first_addr <= addr && addr < second_addr) {
 613                         sprintf(errmsg, "invalid destination");
 614                         return ERR;
 615                 }
 616                 GET_COMMAND_SUFFIX();
 617                 if (!isglobal) clear_undo_stack();
 618                 if (move_lines(addr) < 0)
 619                         return ERR;
 620                 break;
 621         case 'n':
 622                 if (check_addr_range(current_addr, current_addr) < 0)
 623                         return ERR;
 624                 GET_COMMAND_SUFFIX();
 625                 if (display_lines(first_addr, second_addr, gflag | GNP) < 0)
 626                         return ERR;
 627                 gflag = 0;
 628                 break;
 629         case 'p':
 630                 if (check_addr_range(current_addr, current_addr) < 0)
 631                         return ERR;
 632                 GET_COMMAND_SUFFIX();
 633                 if (display_lines(first_addr, second_addr, gflag | GPR) < 0)
 634                         return ERR;
 635                 gflag = 0;
 636                 break;
 637         case 'P':
 638                 if (addr_cnt > 0) {
 639                         sprintf(errmsg, "unexpected address");
 640                         return ERR;
 641                 }
 642                 GET_COMMAND_SUFFIX();
 643                 prompt = prompt ? NULL : optarg ? optarg : dps;
 644                 break;
 645         case 'q':
 646         case 'Q':
 647                 if (addr_cnt > 0) {
 648                         sprintf(errmsg, "unexpected address");
 649                         return ERR;
 650                 }
 651                 GET_COMMAND_SUFFIX();
 652                 gflag =  (modified && !scripted && c == 'q') ? EMOD : EOF;
 653                 break;
 654         case 'r':
 655                 if (!isspace((unsigned char)*ibufp)) {
 656                         sprintf(errmsg, "unexpected command suffix");
 657                         return ERR;
 658                 } else if (addr_cnt == 0)
 659                         second_addr = addr_last;
 660                 if ((fnp = get_filename()) == NULL)
 661                         return ERR;
 662                 GET_COMMAND_SUFFIX();
 663                 if (!isglobal) clear_undo_stack();
 664                 if (*old_filename == '\0' && *fnp != '!')
 665                         strcpy(old_filename, fnp);
 666 #ifdef BACKWARDS
 667                 if (*fnp == '\0' && *old_filename == '\0') {
 668                         sprintf(errmsg, "no current filename");
 669                         return ERR;
 670                 }
 671 #endif
 672                 if ((addr = read_file(*fnp ? fnp : old_filename, second_addr)) < 0)
 673                         return ERR;
 674                 else if (addr && addr != addr_last)
 675                         modified = 1;
 676                 break;
 677         case 's':
 678                 do {
 679                         switch(*ibufp) {
 680                         case '\n':
 681                                 sflags |=SGF;
 682                                 break;
 683                         case 'g':
 684                                 sflags |= SGG;
 685                                 ibufp++;
 686                                 break;
 687                         case 'p':
 688                                 sflags |= SGP;
 689                                 ibufp++;
 690                                 break;
 691                         case 'r':
 692                                 sflags |= SGR;
 693                                 ibufp++;
 694                                 break;
 695                         case '0': case '1': case '2': case '3': case '4':
 696                         case '5': case '6': case '7': case '8': case '9':
 697                                 STRTOL(sgnum, ibufp);
 698                                 sflags |= SGF;
 699                                 sgflag &= ~GSG;         /* override GSG */
 700                                 break;
 701                         default:
 702                                 if (sflags) {
 703                                         sprintf(errmsg, "invalid command suffix");
 704                                         return ERR;
 705                                 }
 706                         }
 707                 } while (sflags && *ibufp != '\n');
 708                 if (sflags && !pat) {
 709                         sprintf(errmsg, "no previous substitution");
 710                         return ERR;
 711                 } else if (sflags & SGG)
 712                         sgnum = 0;              /* override numeric arg */
 713                 if (*ibufp != '\n' && *(ibufp + 1) == '\n') {
 714                         sprintf(errmsg, "invalid pattern delimiter");
 715                         return ERR;
 716                 }
 717                 tpat = pat;
 718                 SPL1();
 719                 if ((!sflags || (sflags & SGR)) &&
 720                     (tpat = get_compiled_pattern()) == NULL) {
 721                         SPL0();
 722                         return ERR;
 723                 } else if (tpat != pat) {
 724                         if (pat) {
 725                                 regfree(pat);
 726                                 free(pat);
 727                         }
 728                         pat = tpat;
 729                         patlock = 1;            /* reserve pattern */
 730                 }
 731                 SPL0();
 732                 if (!sflags && extract_subst_tail(&sgflag, &sgnum) < 0)
 733                         return ERR;
 734                 else if (isglobal)
 735                         sgflag |= GLB;
 736                 else
 737                         sgflag &= ~GLB;
 738                 if (sflags & SGG)
 739                         sgflag ^= GSG;
 740                 if (sflags & SGP)
 741                         sgflag ^= GPR, sgflag &= ~(GLS | GNP);
 742                 do {
 743                         switch(*ibufp) {
 744                         case 'p':
 745                                 sgflag |= GPR, ibufp++;
 746                                 break;
 747                         case 'l':
 748                                 sgflag |= GLS, ibufp++;
 749                                 break;
 750                         case 'n':
 751                                 sgflag |= GNP, ibufp++;
 752                                 break;
 753                         default:
 754                                 n++;
 755                         }
 756                 } while (!n);
 757                 if (check_addr_range(current_addr, current_addr) < 0)
 758                         return ERR;
 759                 GET_COMMAND_SUFFIX();
 760                 if (!isglobal) clear_undo_stack();
 761                 if (search_and_replace(pat, sgflag, sgnum) < 0)
 762                         return ERR;
 763                 break;
 764         case 't':
 765                 if (check_addr_range(current_addr, current_addr) < 0)
 766                         return ERR;
 767                 GET_THIRD_ADDR(addr);
 768                 GET_COMMAND_SUFFIX();
 769                 if (!isglobal) clear_undo_stack();
 770                 if (copy_lines(addr) < 0)
 771                         return ERR;
 772                 break;
 773         case 'u':
 774                 if (addr_cnt > 0) {
 775                         sprintf(errmsg, "unexpected address");
 776                         return ERR;
 777                 }
 778                 GET_COMMAND_SUFFIX();
 779                 if (pop_undo_stack() < 0)
 780                         return ERR;
 781                 break;
 782         case 'w':
 783         case 'W':
 784                 if ((n = *ibufp) == 'q' || n == 'Q') {
 785                         gflag = EOF;
 786                         ibufp++;
 787                 }
 788                 if (!isspace((unsigned char)*ibufp)) {
 789                         sprintf(errmsg, "unexpected command suffix");
 790                         return ERR;
 791                 } else if ((fnp = get_filename()) == NULL)
 792                         return ERR;
 793                 if (addr_cnt == 0 && !addr_last)
 794                         first_addr = second_addr = 0;
 795                 else if (check_addr_range(1, addr_last) < 0)
 796                         return ERR;
 797                 GET_COMMAND_SUFFIX();
 798                 if (*old_filename == '\0' && *fnp != '!')
 799                         strcpy(old_filename, fnp);
 800 #ifdef BACKWARDS
 801                 if (*fnp == '\0' && *old_filename == '\0') {
 802                         sprintf(errmsg, "no current filename");
 803                         return ERR;
 804                 }
 805 #endif
 806                 if ((addr = write_file(*fnp ? fnp : old_filename,
 807                     (c == 'W') ? "a" : "w", first_addr, second_addr)) < 0)
 808                         return ERR;
 809                 else if (addr == addr_last)
 810                         modified = 0;
 811                 else if (modified && !scripted && n == 'q')
 812                         gflag = EMOD;
 813                 break;
 814         case 'x':
 815                 if (addr_cnt > 0) {
 816                         sprintf(errmsg, "unexpected address");
 817                         return ERR;
 818                 }
 819                 GET_COMMAND_SUFFIX();
 820 #ifdef DES
 821                 des = get_keyword();
 822 #else
 823                 sprintf(errmsg, "crypt unavailable");
 824                 return ERR;
 825 #endif
 826                 break;
 827         case 'z':
 828 #ifdef BACKWARDS
 829                 if (check_addr_range(first_addr = 1, current_addr + 1) < 0)
 830 #else
 831                 if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0)
 832 #endif
 833                         return ERR;
 834                 else if ('0' < *ibufp && *ibufp <= '9')
 835                         STRTOL(rows, ibufp);
 836                 GET_COMMAND_SUFFIX();
 837                 if (display_lines(second_addr, min(addr_last,
 838                     second_addr + rows), gflag) < 0)
 839                         return ERR;
 840                 gflag = 0;
 841                 break;
 842         case '=':
 843                 GET_COMMAND_SUFFIX();
 844                 printf("%ld\n", addr_cnt ? second_addr : addr_last);
 845                 break;
 846         case '!':
 847                 if (addr_cnt > 0) {
 848                         sprintf(errmsg, "unexpected address");
 849                         return ERR;
 850                 } else if ((sflags = get_shell_command()) < 0)
 851                         return ERR;
 852                 GET_COMMAND_SUFFIX();
 853                 if (sflags) printf("%s\n", shcmd + 1);
 854                 system(shcmd + 1);
 855                 if (!scripted) printf("!\n");
 856                 break;
 857         case '\n':
 858 #ifdef BACKWARDS
 859                 if (check_addr_range(first_addr = 1, current_addr + 1) < 0
 860 #else
 861                 if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0
 862 #endif
 863                  || display_lines(second_addr, second_addr, 0) < 0)
 864                         return ERR;
 865                 break;
 866         default:
 867                 sprintf(errmsg, "unknown command");
 868                 return ERR;
 869         }
 870         return gflag;
 871 }
 872
 873
 874 /* check_addr_range: return status of address range check */
 875 int
 876 check_addr_range(n, m)
 877         long n, 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                 sprintf(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(pat, dir)
 897         pattern_t *pat;
 898         int dir;
 899 {
 900         char *s;
 901         long n = current_addr;
 902         line_t *lp;
 903
 904         if (!pat) return ERR;
 905         do {
 906                if ((n = dir ? INC_MOD(n, addr_last) : DEC_MOD(n, addr_last))) {
 907                         lp = get_addressed_line_node(n);
 908                         if ((s = get_sbuf_line(lp)) == NULL)
 909                                 return ERR;
 910                         if (isbinary)
 911                                 NUL_TO_NEWLINE(s, lp->len);
 912                         if (!regexec(pat, s, 0, NULL, 0))
 913                                 return n;
 914                }
 915         } while (n != current_addr);
 916         sprintf(errmsg, "no match");
 917         return  ERR;
 918 }
 919
 920
 921 /* get_filename: return pointer to copy of filename in the command buffer */
 922 char *
 923 get_filename()
 924 {
 925         static char *file = NULL;
 926         static int filesz = 0;
 927
 928         int n;
 929
 930         if (*ibufp != '\n') {
 931                 SKIP_BLANKS();
 932                 if (*ibufp == '\n') {
 933                         sprintf(errmsg, "invalid filename");
 934                         return NULL;
 935                 } else if ((ibufp = get_extended_line(&n, 1)) == NULL)
 936                         return NULL;
 937                 else if (*ibufp == '!') {
 938                         ibufp++;
 939                         if ((n = get_shell_command()) < 0)
 940                                 return NULL;
 941                         if (n)
 942                                 printf("%s\n", shcmd + 1);
 943                         return shcmd;
 944                 } else if (n > PATH_MAX - 1) {
 945                         sprintf(errmsg, "filename too long");
 946                         return  NULL;
 947                 }
 948         }
 949 #ifndef BACKWARDS
 950         else if (*old_filename == '\0') {
 951                 sprintf(errmsg, "no current filename");
 952                 return  NULL;
 953         }
 954 #endif
 955         REALLOC(file, filesz, PATH_MAX, NULL);
 956         for (n = 0; *ibufp != '\n';)
 957                 file[n++] = *ibufp++;
 958         file[n] = '\0';
 959         return is_legal_filename(file) ? file : NULL;
 960 }
 961
 962
 963 /* get_shell_command: read a shell command from stdin; return substitution
 964    status */
 965 int
 966 get_shell_command()
 967 {
 968         static char *buf = NULL;
 969         static int n = 0;
 970
 971         char *s;                        /* substitution char pointer */
 972         int i = 0;
 973         int j = 0;
 974
 975         if (red) {
 976                 sprintf(errmsg, "shell access restricted");
 977                 return ERR;
 978         } else if ((s = ibufp = get_extended_line(&j, 1)) == NULL)
 979                 return ERR;
 980         REALLOC(buf, n, j + 1, ERR);
 981         buf[i++] = '!';                 /* prefix command w/ bang */
 982         while (*ibufp != '\n')
 983                 switch (*ibufp) {
 984                 default:
 985                         REALLOC(buf, n, i + 2, ERR);
 986                         buf[i++] = *ibufp;
 987                         if (*ibufp++ == '\\')
 988                                 buf[i++] = *ibufp++;
 989                         break;
 990                 case '!':
 991                         if (s != ibufp) {
 992                                 REALLOC(buf, n, i + 1, ERR);
 993                                 buf[i++] = *ibufp++;
 994                         }
 995 #ifdef BACKWARDS
 996                         else if (shcmd == NULL || *(shcmd + 1) == '\0')
 997 #else
 998                         else if (shcmd == NULL)
 999 #endif
1000                         {
1001                                 sprintf(errmsg, "no previous command");
1002                                 return ERR;
1003                         } else {
1004                                 REALLOC(buf, n, i + shcmdi, ERR);
1005                                 for (s = shcmd + 1; s < shcmd + shcmdi;)
1006                                         buf[i++] = *s++;
1007                                 s = ibufp++;
1008                         }
1009                         break;
1010                 case '%':
1011                         if (*old_filename  == '\0') {
1012                                 sprintf(errmsg, "no current filename");
1013                                 return ERR;
1014                         }
1015                         j = strlen(s = strip_escapes(old_filename));
1016                         REALLOC(buf, n, i + j, ERR);
1017                         while (j--)
1018                                 buf[i++] = *s++;
1019                         s = ibufp++;
1020                         break;
1021                 }
1022         REALLOC(shcmd, shcmdsz, i + 1, ERR);
1023         memcpy(shcmd, buf, i);
1024         shcmd[shcmdi = i] = '\0';
1025         return *s == '!' || *s == '%';
1026 }
1027
1028
1029 /* append_lines: insert text from stdin to after line n; stop when either a
1030    single period is read or EOF; return status */
1031 int
1032 append_lines(n)
1033         long n;
1034 {
1035         int l;
1036         char *lp = ibuf;
1037         char *eot;
1038         undo_t *up = NULL;
1039
1040         for (current_addr = n;;) {
1041                 if (!isglobal) {
1042                         if ((l = get_tty_line()) < 0)
1043                                 return ERR;
1044                         else if (l == 0 || ibuf[l - 1] != '\n') {
1045                                 clearerr(stdin);
1046                                 return  l ? EOF : 0;
1047                         }
1048                         lp = ibuf;
1049                 } else if (*(lp = ibufp) == '\0')
1050                         return 0;
1051                 else {
1052                         while (*ibufp++ != '\n')
1053                                 ;
1054                         l = ibufp - lp;
1055                 }
1056                 if (l == 2 && lp[0] == '.' && lp[1] == '\n') {
1057                         return 0;
1058                 }
1059                 eot = lp + l;
1060                 SPL1();
1061                 do {
1062                         if ((lp = put_sbuf_line(lp)) == NULL) {
1063                                 SPL0();
1064                                 return ERR;
1065                         } else if (up)
1066                                 up->t = get_addressed_line_node(current_addr);
1067                         else if ((up = push_undo_stack(UADD, current_addr,
1068                             current_addr)) == NULL) {
1069                                 SPL0();
1070                                 return ERR;
1071                         }
1072                 } while (lp != eot);
1073                 modified = 1;
1074                 SPL0();
1075         }
1076         /* NOTREACHED */
1077 }
1078
1079
1080 /* join_lines: replace a range of lines with the joined text of those lines */
1081 int
1082 join_lines(from, to)
1083         long from;
1084         long to;
1085 {
1086         static char *buf = NULL;
1087         static int n;
1088
1089         char *s;
1090         int size = 0;
1091         line_t *bp, *ep;
1092
1093         ep = get_addressed_line_node(INC_MOD(to, addr_last));
1094         bp = get_addressed_line_node(from);
1095         for (; bp != ep; bp = bp->q_forw) {
1096                 if ((s = get_sbuf_line(bp)) == NULL)
1097                         return ERR;
1098                 REALLOC(buf, n, size + bp->len, ERR);
1099                 memcpy(buf + size, s, bp->len);
1100                 size += bp->len;
1101         }
1102         REALLOC(buf, n, size + 2, ERR);
1103         memcpy(buf + size, "\n", 2);
1104         if (delete_lines(from, to) < 0)
1105                 return ERR;
1106         current_addr = from - 1;
1107         SPL1();
1108         if (put_sbuf_line(buf) == NULL ||
1109             push_undo_stack(UADD, current_addr, current_addr) == NULL) {
1110                 SPL0();
1111                 return ERR;
1112         }
1113         modified = 1;
1114         SPL0();
1115         return 0;
1116 }
1117
1118
1119 /* move_lines: move a range of lines */
1120 int
1121 move_lines(addr)
1122         long addr;
1123 {
1124         line_t *b1, *a1, *b2, *a2;
1125         long n = INC_MOD(second_addr, addr_last);
1126         long p = first_addr - 1;
1127         int done = (addr == first_addr - 1 || addr == second_addr);
1128
1129         SPL1();
1130         if (done) {
1131                 a2 = get_addressed_line_node(n);
1132                 b2 = get_addressed_line_node(p);
1133                 current_addr = second_addr;
1134         } else if (push_undo_stack(UMOV, p, n) == NULL ||
1135             push_undo_stack(UMOV, addr, INC_MOD(addr, addr_last)) == NULL) {
1136                 SPL0();
1137                 return ERR;
1138         } else {
1139                 a1 = get_addressed_line_node(n);
1140                 if (addr < first_addr) {
1141                         b1 = get_addressed_line_node(p);
1142                         b2 = get_addressed_line_node(addr);
1143                                         /* this get_addressed_line_node last! */
1144                 } else {
1145                         b2 = get_addressed_line_node(addr);
1146                         b1 = get_addressed_line_node(p);
1147                                         /* this get_addressed_line_node last! */
1148                 }
1149                 a2 = b2->q_forw;
1150                 REQUE(b2, b1->q_forw);
1151                 REQUE(a1->q_back, a2);
1152                 REQUE(b1, a1);
1153                 current_addr = addr + ((addr < first_addr) ?
1154                     second_addr - first_addr + 1 : 0);
1155         }
1156         if (isglobal)
1157                 unset_active_nodes(b2->q_forw, a2);
1158         modified = 1;
1159         SPL0();
1160         return 0;
1161 }
1162
1163
1164 /* copy_lines: copy a range of lines; return status */
1165 int
1166 copy_lines(addr)
1167         long addr;
1168 {
1169         line_t *lp, *np = get_addressed_line_node(first_addr);
1170         undo_t *up = NULL;
1171         long n = second_addr - first_addr + 1;
1172         long m = 0;
1173
1174         current_addr = addr;
1175         if (first_addr <= addr && addr < second_addr) {
1176                 n =  addr - first_addr + 1;
1177                 m = second_addr - addr;
1178         }
1179         for (; n > 0; n=m, m=0, np = get_addressed_line_node(current_addr + 1))
1180                 for (; n-- > 0; np = np->q_forw) {
1181                         SPL1();
1182                         if ((lp = dup_line_node(np)) == NULL) {
1183                                 SPL0();
1184                                 return ERR;
1185                         }
1186                         add_line_node(lp);
1187                         if (up)
1188                                 up->t = lp;
1189                         else if ((up = push_undo_stack(UADD, current_addr,
1190                             current_addr)) == NULL) {
1191                                 SPL0();
1192                                 return ERR;
1193                         }
1194                         modified = 1;
1195                         SPL0();
1196                 }
1197         return 0;
1198 }
1199
1200
1201 /* delete_lines: delete a range of lines */
1202 int
1203 delete_lines(from, to)
1204         long from, to;
1205 {
1206         line_t *n, *p;
1207
1208         SPL1();
1209         if (push_undo_stack(UDEL, from, to) == NULL) {
1210                 SPL0();
1211                 return ERR;
1212         }
1213         n = get_addressed_line_node(INC_MOD(to, addr_last));
1214         p = get_addressed_line_node(from - 1);
1215                                         /* this get_addressed_line_node last! */
1216         if (isglobal)
1217                 unset_active_nodes(p->q_forw, n);
1218         REQUE(p, n);
1219         addr_last -= to - from + 1;
1220         current_addr = from - 1;
1221         modified = 1;
1222         SPL0();
1223         return 0;
1224 }
1225
1226
1227 /* display_lines: print a range of lines to stdout */
1228 int
1229 display_lines(from, to, gflag)
1230         long from;
1231         long to;
1232         int gflag;
1233 {
1234         line_t *bp;
1235         line_t *ep;
1236         char *s;
1237
1238         if (!from) {
1239                 sprintf(errmsg, "invalid address");
1240                 return ERR;
1241         }
1242         ep = get_addressed_line_node(INC_MOD(to, addr_last));
1243         bp = get_addressed_line_node(from);
1244         for (; bp != ep; bp = bp->q_forw) {
1245                 if ((s = get_sbuf_line(bp)) == NULL)
1246                         return ERR;
1247                 if (put_tty_line(s, bp->len, current_addr = from++, gflag) < 0)
1248                         return ERR;
1249         }
1250         return 0;
1251 }
1252
1253
1254 #define MAXMARK 26                      /* max number of marks */
1255
1256 line_t  *mark[MAXMARK];                 /* line markers */
1257 int markno;                             /* line marker count */
1258
1259 /* mark_line_node: set a line node mark */
1260 int
1261 mark_line_node(lp, n)
1262         line_t *lp;
1263         int n;
1264 {
1265         if (!islower((unsigned char)n)) {
1266                 sprintf(errmsg, "invalid mark character");
1267                 return ERR;
1268         } else if (mark[n - 'a'] == NULL)
1269                 markno++;
1270         mark[n - 'a'] = lp;
1271         return 0;
1272 }
1273
1274
1275 /* get_marked_node_addr: return address of a marked line */
1276 long
1277 get_marked_node_addr(n)
1278         int n;
1279 {
1280         if (!islower((unsigned char)n)) {
1281                 sprintf(errmsg, "invalid mark character");
1282                 return ERR;
1283         }
1284         return get_line_node_addr(mark[n - 'a']);
1285 }
1286
1287
1288 /* unmark_line_node: clear line node mark */
1289 void
1290 unmark_line_node(lp)
1291         line_t *lp;
1292 {
1293         int i;
1294
1295         for (i = 0; markno && i < MAXMARK; i++)
1296                 if (mark[i] == lp) {
1297                         mark[i] = NULL;
1298                         markno--;
1299                 }
1300 }
1301
1302
1303 /* dup_line_node: return a pointer to a copy of a line node */
1304 line_t *
1305 dup_line_node(lp)
1306         line_t *lp;
1307 {
1308         line_t *np;
1309
1310         if ((np = (line_t *) malloc(sizeof(line_t))) == NULL) {
1311                 fprintf(stderr, "%s\n", strerror(errno));
1312                 sprintf(errmsg, "out of memory");
1313                 return NULL;
1314         }
1315         np->seek = lp->seek;
1316         np->len = lp->len;
1317         return np;
1318 }
1319
1320
1321 /* has_trailing_escape:  return the parity of escapes preceding a character
1322    in a string */
1323 int
1324 has_trailing_escape(s, t)
1325         char *s;
1326         char *t;
1327 {
1328     return (s == t || *(t - 1) != '\\') ? 0 : !has_trailing_escape(s, t - 1);
1329 }
1330
1331
1332 /* strip_escapes: return copy of escaped string of at most length PATH_MAX */
1333 char *
1334 strip_escapes(s)
1335         char *s;
1336 {
1337         static char *file = NULL;
1338         static int filesz = 0;
1339
1340         int i = 0;
1341
1342         REALLOC(file, filesz, PATH_MAX, NULL);
1343         while (i < filesz - 1   /* Worry about a possible trailing escape */
1344                && (file[i++] = (*s == '\\') ? *++s : *s))
1345                 s++;
1346         return file;
1347 }
1348
1349
1350 void
1351 signal_hup(signo)
1352         int signo;
1353 {
1354         if (mutex)
1355                 sigflags |= (1 << (signo - 1));
1356         else
1357                 handle_hup(signo);
1358 }
1359
1360
1361 void
1362 signal_int(signo)
1363         int signo;
1364 {
1365         if (mutex)
1366                 sigflags |= (1 << (signo - 1));
1367         else
1368                 handle_int(signo);
1369 }
1370
1371
1372 void
1373 handle_hup(signo)
1374         int signo;
1375 {
1376         char *hup = NULL;               /* hup filename */
1377         char *s;
1378         int n;
1379
1380         if (!sigactive)
1381                 quit(1);
1382         sigflags &= ~(1 << (signo - 1));
1383         if (addr_last && write_file("ed.hup", "w", 1, addr_last) < 0 &&
1384             (s = getenv("HOME")) != NULL &&
1385             (n = strlen(s)) + 8 <= PATH_MAX &&  /* "ed.hup" + '/' */
1386             (hup = (char *) malloc(n + 10)) != NULL) {
1387                 strcpy(hup, s);
1388                 if (hup[n - 1] != '/')
1389                         hup[n] = '/', hup[n+1] = '\0';
1390                 strcat(hup, "ed.hup");
1391                 write_file(hup, "w", 1, addr_last);
1392         }
1393         quit(2);
1394 }
1395
1396
1397 void
1398 handle_int(signo)
1399         int signo;
1400 {
1401         if (!sigactive)
1402                 quit(1);
1403         sigflags &= ~(1 << (signo - 1));
1404 #ifdef _POSIX_SOURCE
1405         siglongjmp(env, -1);
1406 #else
1407         longjmp(env, -1);
1408 #endif
1409 }
1410
1411
1412 int cols = 72;                          /* wrap column */
1413
1414 void
1415 handle_winch(signo)
1416         int signo;
1417 {
1418         int save_errno = errno;
1419
1420         struct winsize ws;              /* window size structure */
1421
1422         sigflags &= ~(1 << (signo - 1));
1423         if (ioctl(0, TIOCGWINSZ, (char *) &ws) >= 0) {
1424                 if (ws.ws_row > 2) rows = ws.ws_row - 2;
1425                 if (ws.ws_col > 8) cols = ws.ws_col - 8;
1426         }
1427         errno = save_errno;
1428 }
1429
1430
1431 /* is_legal_filename: return a legal filename */
1432 int
1433 is_legal_filename(s)
1434         char *s;
1435 {
1436         if (red && (*s == '!' || !strcmp(s, "..") || strchr(s, '/'))) {
1437                 sprintf(errmsg, "shell access restricted");
1438                 return 0;
1439         }
1440         return 1;
1441 }