text_cmds/ed/main.c

   1 /* main.c: This file contains the main control and user-interface routines
   2    for the ed line editor. */
   3 /*-
   4  * Copyright (c) 1993 Andrew Moore, Talke Studio.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #ifndef lint
  30 #if 0
  31 static const char copyright[] =
  32 "@(#) Copyright (c) 1993 Andrew Moore, Talke Studio. \n\
  33  All rights reserved.\n";
  34 #endif
  35 #endif /* not lint */
  36
  37 /*
  38  * CREDITS
  39  *
  40  *      This program is based on the editor algorithm described in
  41  *      Brian W. Kernighan and P. J. Plauger's book "Software Tools
  42  *      in Pascal," Addison-Wesley, 1981.
  43  *
  44  *      The buffering algorithm is attributed to Rodney Ruddock of
  45  *      the University of Guelph, Guelph, Ontario.
  46  *
  47  *      The cbc.c encryption code is adapted from
  48  *      the bdes program by Matt Bishop of Dartmouth College,
  49  *      Hanover, NH.
  50  *
  51  */
  52
  53 #include <sys/types.h>
  54
  55 #include <sys/ioctl.h>
  56 #include <sys/wait.h>
  57 #include <ctype.h>
  58 #include <locale.h>
  59 #include <pwd.h>
  60 #include <setjmp.h>
  61
  62 #ifdef __APPLE__
  63 #include <get_compat.h>
  64 #else
  65 #define COMPAT_MODE(a,b) (1)
  66 #endif /* __APPLE__ */
  67
  68 #include "ed.h"
  69
  70
  71 #ifdef _POSIX_SOURCE
  72 sigjmp_buf env;
  73 #else
  74 jmp_buf env;
  75 #endif
  76
  77 /* static buffers */
  78 char stdinbuf[1];               /* stdin buffer */
  79 char *shcmd;                    /* shell command buffer */
  80 int shcmdsz;                    /* shell command buffer size */
  81 int shcmdi;                     /* shell command buffer index */
  82 char *ibuf;                     /* ed command-line buffer */
  83 int ibufsz;                     /* ed command-line buffer size */
  84 char *ibufp;                    /* pointer to ed command-line buffer */
  85
  86 /* global flags */
  87 int des = 0;                    /* if set, use crypt(3) for i/o */
  88 int garrulous = 0;              /* if set, print all error messages */
  89 int isbinary;                   /* if set, buffer contains ASCII NULs */
  90 int isglobal;                   /* if set, doing a global command */
  91 int modified;                   /* if set, buffer modified since last write */
  92 int mutex = 0;                  /* if set, signals set "sigflags" */
  93 int red = 0;                    /* if set, restrict shell/directory access */
  94 int scripted = 0;               /* if set, suppress diagnostics */
  95 int sigflags = 0;               /* if set, signals received while mutex set */
  96 int sigactive = 0;              /* if set, signal handlers are enabled */
  97 int posixly_correct = 0;        /* if set, POSIX behavior as per */
  98 /* http://www.opengroup.org/onlinepubs/009695399/utilities/ed.html */
  99
 100 char old_filename[PATH_MAX + 1] = "";   /* default filename */
 101 long current_addr;              /* current address in editor buffer */
 102 long addr_last;                 /* last address in editor buffer */
 103 int lineno;                     /* script line number */
 104 const char *prompt;             /* command-line prompt */
 105 const char *dps = "*";          /* default command-line prompt */
 106
 107 const char usage[] = "usage: %s [-] [-sx] [-p string] [file]\n";
 108
 109 /* ed: line editor */
 110 int
 111 main(int argc, char *argv[])
 112 {
 113         int c, n;
 114         long status = 0;
 115 #if __GNUC__
 116         /* Avoid longjmp clobbering */
 117         (void) &argc;
 118         (void) &argv;
 119 #endif
 120
 121         (void)setlocale(LC_ALL, "");
 122
 123         posixly_correct = COMPAT_MODE("bin/ed", "Unix2003");
 124
 125         red = argv[0]!=NULL && (n = strlen(argv[0])) > 2 && argv[0][n - 3] == 'r';
 126 top:
 127         while ((c = getopt(argc, argv, "p:sx")) != -1)
 128                 switch(c) {
 129                 case 'p':                               /* set prompt */
 130                         prompt = optarg;
 131                         break;
 132                 case 's':                               /* run script */
 133                         scripted = 1;
 134                         break;
 135                 case 'x':                               /* use crypt */
 136 #ifdef DES
 137                         des = get_keyword();
 138 #else
 139                         fprintf(stderr, "crypt unavailable\n?\n");
 140 #endif
 141                         break;
 142
 143                 default:
 144                         fprintf(stderr, usage, red ? "red" : "ed");
 145                         exit(1);
 146                 }
 147         argv += optind;
 148         argc -= optind;
 149         if (argc>0 && *argv && !strcmp(*argv, "-")) {
 150                 scripted = 1;
 151                 if (argc > 1) {
 152                         optind = 1;
 153                         goto top;
 154                 }
 155                 argv++;
 156                 argc--;
 157         }
 158         /* assert: reliable signals! */
 159 #ifdef SIGWINCH
 160         handle_winch(SIGWINCH);
 161         if (isatty(0)) signal(SIGWINCH, handle_winch);
 162 #endif
 163         signal(SIGHUP, signal_hup);
 164         signal(SIGQUIT, SIG_IGN);
 165         signal(SIGINT, signal_int);
 166 #ifdef _POSIX_SOURCE
 167         if ((status = sigsetjmp(env, 1)))
 168 #else
 169         if ((status = setjmp(env)))
 170 #endif
 171         {
 172                 fputs("\n?\n", stderr);
 173                 errmsg = "interrupt";
 174         } else {
 175                 init_buffers();
 176                 sigactive = 1;                  /* enable signal handlers */
 177                 if (argc>0 && *argv && is_legal_filename(*argv)) {
 178                         if (read_file(*argv, 0) < 0 && !isatty(0))
 179                                 quit(2);
 180                         else if (**argv != '!') {
 181                                 if (strlen(*argv) < sizeof(old_filename)) {
 182                                         strcpy(old_filename, *argv);
 183                                 } else {
 184                                         fprintf(stderr, "%s: filename too long\n", *argv);
 185                                         quit(2);
 186                                 }
 187                         }
 188                 } else if (argc>0) {
 189                         fputs("?\n", stdout);
 190                         if (**argv == '\0')
 191                                 errmsg = "invalid filename";
 192                         if (!isatty(0))
 193                                 quit(2);
 194                 }
 195         }
 196         for (;;) {
 197                 if (status < 0 && garrulous)
 198                         fprintf(stderr, "%s\n", errmsg);
 199                 if (prompt) {
 200                         printf("%s", prompt);
 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                                 errmsg = "warning: file modified";
 210                                 if (!isatty(0)) {
 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                         errmsg = "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 ||
 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                         errmsg = "warning: file modified";
 243                         if (!isatty(0)) {
 244                                 fprintf(stderr, garrulous ?
 245                                     "script, line %d: %s\n" :
 246                                     "", lineno, errmsg);
 247                                 quit(2);
 248                         }
 249                         break;
 250                 case FATAL:
 251                         if (!isatty(0))
 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", stdout);
 261                         if (!isatty(0)) {
 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 long 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         long 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() while (isspace((unsigned char)*ibufp) && *ibufp != '\n') ibufp++
 300
 301 #define MUST_BE_FIRST() do {                                    \
 302         if (!first) {                                           \
 303                 errmsg = "invalid address";                     \
 304                 return ERR;                                     \
 305         }                                                       \
 306 } while (0);
 307
 308 /*  next_addr: return the next line address in the command buffer */
 309 long
 310 next_addr(void)
 311 {
 312         const char *hd;
 313         long addr = current_addr;
 314         long n;
 315         int first = 1;
 316         int c;
 317         int add = 0;
 318
 319         SKIP_BLANKS();
 320         for (hd = ibufp;; first = 0)
 321                 switch (c = *ibufp) {
 322                 case '+':
 323                 case '\t':
 324                 case ' ':
 325                 case '-':
 326                 case '^':
 327                         ibufp++;
 328                         SKIP_BLANKS();
 329                         if (isdigit((unsigned char)*ibufp)) {
 330                                 STRTOL(n, ibufp);
 331                                 addr += (c == '-' || c == '^') ? -n : n;
 332                         } else if (!isspace((unsigned char)c))
 333                                 addr += (c == '-' || c == '^') ? -1 : 1;
 334                         break;
 335                 case '0': case '1': case '2':
 336                 case '3': case '4': case '5':
 337                 case '6': case '7': case '8': case '9':
 338                         STRTOL(n, ibufp);
 339                         if (first || !add) /* don't add for ,\d or ;\d */
 340                                 addr = n;
 341                         else
 342                                 addr += n;
 343                         break;
 344                 case '.':
 345                 case '$':
 346                         MUST_BE_FIRST();
 347                         ibufp++;
 348                         addr = (c == '.') ? current_addr : addr_last;
 349                         add++;
 350                         break;
 351                 case '/':
 352                 case '?':
 353                         MUST_BE_FIRST();
 354                         if ((addr = get_matching_node_addr(
 355                             get_compiled_pattern(), c == '/')) < 0)
 356                                 return ERR;
 357                         else if (c == *ibufp)
 358                                 ibufp++;
 359                         add++;
 360                         break;
 361                 case '\'':
 362                         MUST_BE_FIRST();
 363                         ibufp++;
 364                         if ((addr = get_marked_node_addr(*ibufp++)) < 0)
 365                                 return ERR;
 366                         add++;
 367                         break;
 368                 case '%':
 369                 case ',':
 370                 case ';':
 371                         if (first) {
 372                                 ibufp++;
 373                                 addr_cnt++;
 374                                 second_addr = (c == ';') ? current_addr : 1;
 375                                 addr = addr_last;
 376                                 break;
 377                         }
 378                         /* FALLTHROUGH */
 379                 default:
 380                         if (ibufp == hd)
 381                                 return EOF;
 382                         else if (addr < 0 || addr_last < addr) {
 383                                 errmsg = "invalid address";
 384                                 return ERR;
 385                         } else
 386                                 return addr;
 387                 }
 388         /* NOTREACHED */
 389 }
 390
 391
 392 /* GET_THIRD_ADDR: get a legal address from the command buffer */
 393 #define GET_THIRD_ADDR(addr) \
 394 { \
 395         long ol1, ol2; \
 396 \
 397         ol1 = first_addr, ol2 = second_addr; \
 398         if (extract_addr_range() < 0) \
 399                 return ERR; \
 400         else if (!posixly_correct && addr_cnt == 0) { \
 401                 errmsg = "destination expected"; \
 402                 return ERR; \
 403         } else if (second_addr < 0 || addr_last < second_addr) { \
 404                 errmsg = "invalid address"; \
 405                 return ERR; \
 406         } \
 407         addr = second_addr; \
 408         first_addr = ol1, second_addr = ol2; \
 409 }
 410
 411
 412 /* GET_COMMAND_SUFFIX: verify the command suffix in the command buffer */
 413 #define GET_COMMAND_SUFFIX() { \
 414         int done = 0; \
 415         do { \
 416                 switch(*ibufp) { \
 417                 case 'p': \
 418                         gflag |= GPR, ibufp++; \
 419                         break; \
 420                 case 'l': \
 421                         gflag |= GLS, ibufp++; \
 422                         break; \
 423                 case 'n': \
 424                         gflag |= GNP, ibufp++; \
 425                         break; \
 426                 default: \
 427                         done++; \
 428                 } \
 429         } while (!done); \
 430         if (*ibufp++ != '\n') { \
 431                 errmsg = "invalid command suffix"; \
 432                 return ERR; \
 433         } \
 434 }
 435
 436
 437 /* sflags */
 438 #define SGG 001         /* complement previous global substitute suffix */
 439 #define SGP 002         /* complement previous print suffix */
 440 #define SGR 004         /* use last regex instead of last pat */
 441 #define SGF 010         /* repeat last substitution */
 442
 443 int patlock = 0;        /* if set, pattern not freed by get_compiled_pattern() */
 444
 445 long rows = 22;         /* scroll length: ws_row - 2 */
 446
 447 /* exec_command: execute the next command in command buffer; return print
 448    request, if any */
 449 int
 450 exec_command(void)
 451 {
 452         static pattern_t *pat = NULL;
 453         static int sgflag = 0;
 454         static long sgnum = 0;
 455
 456         pattern_t *tpat;
 457         char *fnp;
 458         int gflag = 0;
 459         int sflags = 0;
 460         long addr = 0;
 461         int n = 0;
 462         int c;
 463
 464         SKIP_BLANKS();
 465         switch(c = *ibufp++) {
 466         case 'a':
 467                 GET_COMMAND_SUFFIX();
 468                 if (!isglobal) clear_undo_stack();
 469                 if (append_lines(second_addr) < 0)
 470                         return ERR;
 471                 break;
 472         case 'c':
 473                 if (first_addr == 0)
 474                         first_addr = 1;
 475                 if (check_addr_range(current_addr, current_addr) < 0)
 476                         return ERR;
 477                 GET_COMMAND_SUFFIX();
 478                 if (!isglobal) clear_undo_stack();
 479                 if (delete_lines(first_addr, second_addr) < 0 ||
 480                     append_lines(current_addr) < 0)
 481                         return ERR;
 482                 if (current_addr == 0 && addr_last != 0)
 483                         current_addr = 1;
 484                 break;
 485         case 'd':
 486                 if (check_addr_range(current_addr, current_addr) < 0)
 487                         return ERR;
 488                 GET_COMMAND_SUFFIX();
 489                 if (!isglobal) clear_undo_stack();
 490                 if (delete_lines(first_addr, second_addr) < 0)
 491                         return ERR;
 492                 else if ((addr = INC_MOD(current_addr, addr_last)) != 0)
 493                         current_addr = addr;
 494                 if (current_addr == 0 && addr_last != 0)
 495                         current_addr = 1;
 496                 break;
 497         case 'e':
 498                 if (modified && !scripted)
 499                         return EMOD;
 500                 /* FALLTHROUGH */
 501         case 'E':
 502                 if (addr_cnt > 0) {
 503                         errmsg = "unexpected address";
 504                         return ERR;
 505                 } else if (!isspace((unsigned char)*ibufp)) {
 506                         errmsg = "unexpected command suffix";
 507                         return ERR;
 508                 } else if ((fnp = get_filename()) == NULL)
 509                         return ERR;
 510                 GET_COMMAND_SUFFIX();
 511                 if (delete_lines(1, addr_last) < 0)
 512                         return ERR;
 513                 clear_undo_stack();
 514                 if (close_sbuf() < 0)
 515                         return ERR;
 516                 else if (open_sbuf() < 0)
 517                         return FATAL;
 518                 if (*fnp && *fnp != '!') {
 519                         if (strlen(fnp) < sizeof(old_filename)) {
 520                                 strcpy(old_filename, fnp);
 521                         } else {
 522                                 fprintf(stderr, "%s: filename too long\n", fnp);
 523                                 quit(2);
 524                         }
 525                 }
 526
 527                 if (!posixly_correct && *fnp == '\0' && *old_filename == '\0') {
 528                         errmsg = "no current filename";
 529                         return ERR;
 530                 }
 531                 if (read_file(*fnp ? fnp : old_filename, 0) < 0)
 532                         return ERR;
 533                 clear_undo_stack();
 534                 modified = 0;
 535                 u_current_addr = u_addr_last = -1;
 536                 break;
 537         case 'f':
 538                 if (addr_cnt > 0) {
 539                         errmsg = "unexpected address";
 540                         return ERR;
 541                 } else if (!isspace((unsigned char)*ibufp)) {
 542                         errmsg = "unexpected command suffix";
 543                         return ERR;
 544                 } else if ((fnp = get_filename()) == NULL)
 545                         return ERR;
 546                 else if (*fnp == '!') {
 547                         errmsg = "invalid redirection";
 548                         return ERR;
 549                 }
 550                 GET_COMMAND_SUFFIX();
 551                 if (*fnp) {
 552                         if (strlen(fnp) < sizeof(old_filename)) {
 553                                 strcpy(old_filename, fnp);
 554                         } else {
 555                                 fprintf(stderr, "%s: filename too long\n", fnp);
 556                                 quit(2);
 557                         }
 558                 }
 559                 printf("%s\n", strip_escapes(old_filename));
 560                 break;
 561         case 'g':
 562         case 'v':
 563         case 'G':
 564         case 'V':
 565                 if (isglobal) {
 566                         errmsg = "cannot nest global commands";
 567                         return ERR;
 568                 } else if (check_addr_range(1, addr_last) < 0)
 569                         return ERR;
 570                 else if (build_active_list(c == 'g' || c == 'G') < 0)
 571                         return ERR;
 572                 else if ((n = (c == 'G' || c == 'V')))
 573                         GET_COMMAND_SUFFIX();
 574                 isglobal++;
 575                 n = exec_global(n, gflag);
 576                 if (n == EOF)
 577                         return EOF;
 578                 else if (n < 0)
 579                         return ERR;
 580                 break;
 581         case 'h':
 582                 if (addr_cnt > 0) {
 583                         errmsg = "unexpected address";
 584                         return ERR;
 585                 }
 586                 GET_COMMAND_SUFFIX();
 587                 if (*errmsg) fprintf(stderr, "%s\n", errmsg);
 588                 break;
 589         case 'H':
 590                 if (addr_cnt > 0) {
 591                         errmsg = "unexpected address";
 592                         return ERR;
 593                 }
 594                 GET_COMMAND_SUFFIX();
 595                 if ((garrulous = 1 - garrulous) && *errmsg)
 596                         fprintf(stderr, "%s\n", errmsg);
 597                 break;
 598         case 'i':
 599                 if (second_addr == 0) {
 600                         second_addr = 1;
 601                 }
 602                 GET_COMMAND_SUFFIX();
 603                 if (!isglobal) clear_undo_stack();
 604                 if (append_lines(second_addr - 1) < 0)
 605                         return ERR;
 606                 if (u_addr_last == addr_last) /* nothing inserted */
 607                         current_addr = second_addr;
 608                 break;
 609         case 'j':
 610                 if (check_addr_range(current_addr, current_addr + 1) < 0)
 611                         return ERR;
 612                 GET_COMMAND_SUFFIX();
 613                 if (!isglobal) clear_undo_stack();
 614                 if (first_addr != second_addr &&
 615                     join_lines(first_addr, second_addr) < 0)
 616                         return ERR;
 617                 break;
 618         case 'k':
 619                 c = *ibufp++;
 620                 if (second_addr == 0) {
 621                         errmsg = "invalid address";
 622                         return ERR;
 623                 }
 624                 GET_COMMAND_SUFFIX();
 625                 if (mark_line_node(get_addressed_line_node(second_addr), c) < 0)
 626                         return ERR;
 627                 break;
 628         case 'l':
 629                 if (check_addr_range(current_addr, current_addr) < 0)
 630                         return ERR;
 631                 GET_COMMAND_SUFFIX();
 632                 if (display_lines(first_addr, second_addr, gflag | GLS) < 0)
 633                         return ERR;
 634                 gflag = 0;
 635                 break;
 636         case 'm':
 637                 if (check_addr_range(current_addr, current_addr) < 0)
 638                         return ERR;
 639                 GET_THIRD_ADDR(addr);
 640                 if (first_addr <= addr && addr < second_addr) {
 641                         errmsg = "invalid destination";
 642                         return ERR;
 643                 }
 644                 GET_COMMAND_SUFFIX();
 645                 if (!isglobal) clear_undo_stack();
 646                 if (move_lines(addr) < 0)
 647                         return ERR;
 648                 break;
 649         case 'n':
 650                 if (check_addr_range(current_addr, current_addr) < 0)
 651                         return ERR;
 652                 GET_COMMAND_SUFFIX();
 653                 if (display_lines(first_addr, second_addr, gflag | GNP) < 0)
 654                         return ERR;
 655                 gflag = 0;
 656                 break;
 657         case 'p':
 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 | GPR) < 0)
 662                         return ERR;
 663                 gflag = 0;
 664                 break;
 665         case 'P':
 666                 if (addr_cnt > 0) {
 667                         errmsg = "unexpected address";
 668                         return ERR;
 669                 }
 670                 GET_COMMAND_SUFFIX();
 671                 prompt = prompt ? NULL : optarg ? optarg : dps;
 672                 break;
 673         case 'q':
 674         case 'Q':
 675                 if (addr_cnt > 0) {
 676                         errmsg = "unexpected address";
 677                         return ERR;
 678                 }
 679                 GET_COMMAND_SUFFIX();
 680                 gflag =  (modified && !scripted && c == 'q') ? EMOD : EOF;
 681                 break;
 682         case 'r':
 683                 if (!isspace((unsigned char)*ibufp)) {
 684                         errmsg = "unexpected command suffix";
 685                         return ERR;
 686                 } else if (addr_cnt == 0)
 687                         second_addr = addr_last;
 688                 if ((fnp = get_filename()) == NULL)
 689                         return ERR;
 690                 GET_COMMAND_SUFFIX();
 691                 if (!isglobal) clear_undo_stack();
 692                 if (*old_filename == '\0' && *fnp != '!') {
 693                         if (strlen(fnp) < sizeof(old_filename)) {
 694                                 strcpy(old_filename, fnp);
 695                         } else {
 696                                 fprintf(stderr, "%s: filename too long\n", fnp);
 697                                 quit(2);
 698                         }
 699                 }
 700                 if (!posixly_correct && *fnp == '\0' && *old_filename == '\0') {
 701                         errmsg = "no current filename";
 702                         return ERR;
 703                 }
 704                 if ((addr = read_file(*fnp ? fnp : old_filename, second_addr)) < 0)
 705                         return ERR;
 706                 else if (addr && addr != addr_last)
 707                         modified = 1;
 708                 break;
 709         case 's':
 710                 /*
 711                  * POSIX requires ed to process srabcr123r as
 712                  * replace abc with 123 delimiter='r'
 713                  */
 714                 if (!posixly_correct) do {
 715                         switch(*ibufp) {
 716                         case '\n':
 717                                 sflags |=SGF;
 718                                 break;
 719                         case 'g':
 720                                 sflags |= SGG;
 721                                 ibufp++;
 722                                 break;
 723                         case 'p':
 724                                 sflags |= SGP;
 725                                 ibufp++;
 726                                 break;
 727                         case 'r':
 728                                 sflags |= SGR;
 729                                 ibufp++;
 730                                 break;
 731                         case '0': case '1': case '2': case '3': case '4':
 732                         case '5': case '6': case '7': case '8': case '9':
 733                                 STRTOL(sgnum, ibufp);
 734                                 sflags |= SGF;
 735                                 sgflag &= ~GSG;         /* override GSG */
 736                                 break;
 737                         default:
 738                                 if (sflags) {
 739                                         errmsg = "invalid command suffix";
 740                                         return ERR;
 741                                 }
 742                         }
 743                 } while (sflags && *ibufp != '\n');
 744                 if (sflags && !pat) {
 745                         errmsg = "no previous substitution";
 746                         return ERR;
 747                 } else if (sflags & SGG)
 748                         sgnum = 0;              /* override numeric arg */
 749                 if (*ibufp != '\n' && *(ibufp + 1) == '\n') {
 750                         errmsg = "invalid pattern delimiter";
 751                         return ERR;
 752                 }
 753                 tpat = pat;
 754                 SPL1();
 755                 if ((!sflags || (sflags & SGR)) &&
 756                     (tpat = get_compiled_pattern()) == NULL) {
 757                         SPL0();
 758                         return ERR;
 759                 } else if (tpat != pat) {
 760                         if (pat) {
 761                                 regfree(pat);
 762                                 free(pat);
 763                         }
 764                         pat = tpat;
 765                         patlock = 1;            /* reserve pattern */
 766                 }
 767                 SPL0();
 768                 if (!sflags && extract_subst_tail(&sgflag, &sgnum) < 0)
 769                         return ERR;
 770                 else if (isglobal)
 771                         sgflag |= GLB;
 772                 else
 773                         sgflag &= ~GLB;
 774                 if (sflags & SGG)
 775                         sgflag ^= GSG;
 776                 if (sflags & SGP)
 777                         sgflag ^= GPR, sgflag &= ~(GLS | GNP);
 778                 do {
 779                         switch(*ibufp) {
 780                         case 'p':
 781                                 sgflag |= GPR, ibufp++;
 782                                 break;
 783                         case 'l':
 784                                 sgflag |= GLS, ibufp++;
 785                                 break;
 786                         case 'n':
 787                                 sgflag |= GNP, ibufp++;
 788                                 break;
 789                         default:
 790                                 n++;
 791                         }
 792                 } while (!n);
 793                 if (check_addr_range(current_addr, current_addr) < 0)
 794                         return ERR;
 795                 GET_COMMAND_SUFFIX();
 796                 if (!isglobal) clear_undo_stack();
 797                 if (search_and_replace(pat, sgflag, sgnum) < 0)
 798                         return ERR;
 799                 break;
 800         case 't':
 801                 if (check_addr_range(current_addr, current_addr) < 0)
 802                         return ERR;
 803                 GET_THIRD_ADDR(addr);
 804                 GET_COMMAND_SUFFIX();
 805                 if (!isglobal) clear_undo_stack();
 806                 if (copy_lines(addr) < 0)
 807                         return ERR;
 808                 break;
 809         case 'u':
 810                 if (addr_cnt > 0) {
 811                         errmsg = "unexpected address";
 812                         return ERR;
 813                 }
 814                 GET_COMMAND_SUFFIX();
 815                 if (pop_undo_stack() < 0)
 816                         return ERR;
 817                 break;
 818         case 'w':
 819         case 'W':
 820                 if ((n = *ibufp) == 'q' || n == 'Q') {
 821                         gflag = EOF;
 822                         ibufp++;
 823                 }
 824                 if (!isspace((unsigned char)*ibufp)) {
 825                         errmsg = "unexpected command suffix";
 826                         return ERR;
 827                 } else if ((fnp = get_filename()) == NULL)
 828                         return ERR;
 829                 if (addr_cnt == 0 && !addr_last)
 830                         first_addr = second_addr = 0;
 831                 else if (check_addr_range(1, addr_last) < 0)
 832                         return ERR;
 833                 GET_COMMAND_SUFFIX();
 834                 if (*old_filename == '\0' && *fnp != '!') {
 835                         if  (strlen(fnp) < sizeof(old_filename)) {
 836                                 strcpy(old_filename, fnp);
 837                         } else {
 838                                 fprintf(stderr, "%s: filename too long\n", fnp);
 839                                 quit(2);
 840                         }
 841                 }
 842                 if (!posixly_correct && *fnp == '\0' && *old_filename == '\0') {
 843                         errmsg = "no current filename";
 844                         return ERR;
 845                 }
 846                 if ((addr = write_file(*fnp ? fnp : old_filename,
 847                     (c == 'W') ? "a" : "w", first_addr, second_addr)) < 0)
 848                         return ERR;
 849                 else if (addr == addr_last)
 850                         modified = 0;
 851                 else if (modified && !scripted && n == 'q')
 852                         gflag = EMOD;
 853                 break;
 854         case 'x':
 855                 if (addr_cnt > 0) {
 856                         errmsg = "unexpected address";
 857                         return ERR;
 858                 }
 859                 GET_COMMAND_SUFFIX();
 860 #ifdef DES
 861                 des = get_keyword();
 862                 break;
 863 #else
 864                 errmsg = "crypt unavailable";
 865                 return ERR;
 866 #endif
 867         case 'z':
 868                 if (check_addr_range(first_addr = 1, current_addr + (posixly_correct ? !isglobal : 1)) < 0)
 869                         return ERR;
 870                 else if ('0' < *ibufp && *ibufp <= '9')
 871                         STRTOL(rows, ibufp);
 872                 GET_COMMAND_SUFFIX();
 873                 if (display_lines(second_addr, min(addr_last,
 874                     second_addr + rows), gflag) < 0)
 875                         return ERR;
 876                 gflag = 0;
 877                 break;
 878         case '=':
 879                 GET_COMMAND_SUFFIX();
 880                 printf("%ld\n", addr_cnt ? second_addr : addr_last);
 881                 break;
 882         case '!':
 883                 if (addr_cnt > 0) {
 884                         errmsg = "unexpected address";
 885                         return ERR;
 886                 } else if ((sflags = get_shell_command()) < 0)
 887                         return ERR;
 888                 GET_COMMAND_SUFFIX();
 889                 if (sflags) printf("%s\n", shcmd + 1);
 890                 fflush(stdout);
 891                 system(shcmd + 1);
 892                 if (!scripted) printf("!\n");
 893                 break;
 894         case '\n':
 895                 if (check_addr_range(first_addr = 1, current_addr + (posixly_correct ? !isglobal : 1)) < 0
 896                  || display_lines(second_addr, second_addr, 0) < 0)
 897                         return ERR;
 898                 break;
 899         default:
 900                 errmsg = "unknown command";
 901                 return ERR;
 902         }
 903         return gflag;
 904 }
 905
 906
 907 /* check_addr_range: return status of address range check */
 908 int
 909 check_addr_range(long n, long m)
 910 {
 911         if (addr_cnt == 0) {
 912                 first_addr = n;
 913                 second_addr = m;
 914         }
 915         if (first_addr > second_addr || 1 > first_addr ||
 916             second_addr > addr_last) {
 917                 errmsg = "invalid address";
 918                 return ERR;
 919         }
 920         return 0;
 921 }
 922
 923
 924 /* get_matching_node_addr: return the address of the next line matching a
 925    pattern in a given direction.  wrap around begin/end of editor buffer if
 926    necessary */
 927 long
 928 get_matching_node_addr(pattern_t *pat, int dir)
 929 {
 930         char *s;
 931         long n = current_addr;
 932         line_t *lp;
 933
 934         if (!pat) return ERR;
 935         do {
 936                if ((n = dir ? INC_MOD(n, addr_last) : DEC_MOD(n, addr_last))) {
 937                         lp = get_addressed_line_node(n);
 938                         if ((s = get_sbuf_line(lp)) == NULL)
 939                                 return ERR;
 940                         if (isbinary)
 941                                 NUL_TO_NEWLINE(s, lp->len);
 942                         if (!regexec(pat, s, 0, NULL, 0))
 943                                 return n;
 944                }
 945         } while (n != current_addr);
 946         errmsg = "no match";
 947         return  ERR;
 948 }
 949
 950
 951 /* get_filename: return pointer to copy of filename in the command buffer */
 952 char *
 953 get_filename(void)
 954 {
 955         static char *file = NULL;
 956         static int filesz = 0;
 957
 958         int n;
 959
 960         if (*ibufp != '\n') {
 961                 SKIP_BLANKS();
 962                 if (*ibufp == '\n') {
 963                         errmsg = "invalid filename";
 964                         return NULL;
 965                 } else if ((ibufp = get_extended_line(&n, 1)) == NULL)
 966                         return NULL;
 967                 else if (*ibufp == '!') {
 968                         ibufp++;
 969                         if ((n = get_shell_command()) < 0)
 970                                 return NULL;
 971                         if (n)
 972                                 printf("%s\n", shcmd + 1);
 973                         return shcmd;
 974                 } else if (n > PATH_MAX) {
 975                         errmsg = "filename too long";
 976                         return  NULL;
 977                 }
 978         }
 979         else if (posixly_correct && *old_filename == '\0') {
 980                 errmsg = "no current filename";
 981                 return  NULL;
 982         }
 983         REALLOC(file, filesz, PATH_MAX + 1, NULL);
 984         for (n = 0; *ibufp != '\n';)
 985                 file[n++] = *ibufp++;
 986         file[n] = '\0';
 987         return is_legal_filename(file) ? file : NULL;
 988 }
 989
 990
 991 /* get_shell_command: read a shell command from stdin; return substitution
 992    status */
 993 int
 994 get_shell_command(void)
 995 {
 996         static char *buf = NULL;
 997         static int n = 0;
 998
 999         char *s;                        /* substitution char pointer */
1000         int i = 0;
1001         int j = 0;
1002
1003         if (red) {
1004                 errmsg = "shell access restricted";
1005                 return ERR;
1006         } else if ((s = ibufp = get_extended_line(&j, 1)) == NULL)
1007                 return ERR;
1008         REALLOC(buf, n, j + 1, ERR);
1009         buf[i++] = '!';                 /* prefix command w/ bang */
1010         while (*ibufp != '\n')
1011                 switch (*ibufp) {
1012                 default:
1013                         REALLOC(buf, n, i + 2, ERR);
1014                         buf[i++] = *ibufp;
1015                         if (*ibufp++ == '\\')
1016                                 buf[i++] = *ibufp++;
1017                         break;
1018                 case '!':
1019                         if (s != ibufp) {
1020                                 REALLOC(buf, n, i + 1, ERR);
1021                                 buf[i++] = *ibufp++;
1022                         }
1023                         else if (shcmd == NULL || (!posixly_correct && *(shcmd + 1) == '\0'))
1024                         {
1025                                 errmsg = "no previous command";
1026                                 return ERR;
1027                         } else {
1028                                 REALLOC(buf, n, i + shcmdi, ERR);
1029                                 for (s = shcmd + 1; s < shcmd + shcmdi;)
1030                                         buf[i++] = *s++;
1031                                 s = ibufp++;
1032                         }
1033                         break;
1034                 case '%':
1035                         if (*old_filename  == '\0') {
1036                                 errmsg = "no current filename";
1037                                 return ERR;
1038                         }
1039                         j = strlen(s = strip_escapes(old_filename));
1040                         REALLOC(buf, n, i + j, ERR);
1041                         while (j--)
1042                                 buf[i++] = *s++;
1043                         s = ibufp++;
1044                         break;
1045                 }
1046         REALLOC(shcmd, shcmdsz, i + 1, ERR);
1047         memcpy(shcmd, buf, i);
1048         shcmd[shcmdi = i] = '\0';
1049         return *s == '!' || *s == '%';
1050 }
1051
1052
1053 /* append_lines: insert text from stdin to after line n; stop when either a
1054    single period is read or EOF; return status */
1055 int
1056 append_lines(long n)
1057 {
1058         int l;
1059         const char *lp = ibuf;
1060         const char *eot;
1061         undo_t *up = NULL;
1062
1063         for (current_addr = n;;) {
1064                 if (!isglobal) {
1065                         if ((l = get_tty_line()) < 0)
1066                                 return ERR;
1067                         else if (l == 0 || ibuf[l - 1] != '\n') {
1068                                 clearerr(stdin);
1069                                 return  l ? EOF : 0;
1070                         }
1071                         lp = ibuf;
1072                 } else if (*(lp = ibufp) == '\0')
1073                         return 0;
1074                 else {
1075                         while (*ibufp++ != '\n')
1076                                 ;
1077                         l = ibufp - lp;
1078                 }
1079                 if (l == 2 && lp[0] == '.' && lp[1] == '\n') {
1080                         return 0;
1081                 }
1082                 eot = lp + l;
1083                 SPL1();
1084                 do {
1085                         if ((lp = put_sbuf_line(lp)) == NULL) {
1086                                 SPL0();
1087                                 return ERR;
1088                         } else if (up)
1089                                 up->t = get_addressed_line_node(current_addr);
1090                         else if ((up = push_undo_stack(UADD, current_addr,
1091                             current_addr)) == NULL) {
1092                                 SPL0();
1093                                 return ERR;
1094                         }
1095                 } while (lp != eot);
1096                 modified = 1;
1097                 SPL0();
1098         }
1099         /* NOTREACHED */
1100 }
1101
1102
1103 /* join_lines: replace a range of lines with the joined text of those lines */
1104 int
1105 join_lines(long from, long to)
1106 {
1107         static char *buf = NULL;
1108         static int n;
1109
1110         char *s;
1111         int size = 0;
1112         line_t *bp, *ep;
1113
1114         ep = get_addressed_line_node(INC_MOD(to, addr_last));
1115         bp = get_addressed_line_node(from);
1116         for (; bp != ep; bp = bp->q_forw) {
1117                 if ((s = get_sbuf_line(bp)) == NULL)
1118                         return ERR;
1119                 REALLOC(buf, n, size + bp->len, ERR);
1120                 memcpy(buf + size, s, bp->len);
1121                 size += bp->len;
1122         }
1123         REALLOC(buf, n, size + 2, ERR);
1124         memcpy(buf + size, "\n", 2);
1125         if (delete_lines(from, to) < 0)
1126                 return ERR;
1127         current_addr = from - 1;
1128         SPL1();
1129         if (put_sbuf_line(buf) == NULL ||
1130             push_undo_stack(UADD, current_addr, current_addr) == NULL) {
1131                 SPL0();
1132                 return ERR;
1133         }
1134         modified = 1;
1135         if (current_addr == 0)
1136                 current_addr = 1;
1137         SPL0();
1138         return 0;
1139 }
1140
1141
1142 /* move_lines: move a range of lines */
1143 int
1144 move_lines(long addr)
1145 {
1146         line_t *b1, *a1, *b2, *a2;
1147         long n = INC_MOD(second_addr, addr_last);
1148         long p = first_addr - 1;
1149         int done = (addr == first_addr - 1 || addr == second_addr);
1150
1151         SPL1();
1152         if (done) {
1153                 a2 = get_addressed_line_node(n);
1154                 b2 = get_addressed_line_node(p);
1155                 current_addr = second_addr;
1156         } else if (push_undo_stack(UMOV, p, n) == NULL ||
1157             push_undo_stack(UMOV, addr, INC_MOD(addr, addr_last)) == NULL) {
1158                 SPL0();
1159                 return ERR;
1160         } else {
1161                 a1 = get_addressed_line_node(n);
1162                 if (addr < first_addr) {
1163                         b1 = get_addressed_line_node(p);
1164                         b2 = get_addressed_line_node(addr);
1165                                         /* this get_addressed_line_node last! */
1166                 } else {
1167                         b2 = get_addressed_line_node(addr);
1168                         b1 = get_addressed_line_node(p);
1169                                         /* this get_addressed_line_node last! */
1170                 }
1171                 a2 = b2->q_forw;
1172                 REQUE(b2, b1->q_forw);
1173                 REQUE(a1->q_back, a2);
1174                 REQUE(b1, a1);
1175                 current_addr = addr + ((addr < first_addr) ?
1176                     second_addr - first_addr + 1 : 0);
1177         }
1178         if (isglobal)
1179                 unset_active_nodes(b2->q_forw, a2);
1180         modified = 1;
1181         SPL0();
1182         return 0;
1183 }
1184
1185
1186 /* copy_lines: copy a range of lines; return status */
1187 int
1188 copy_lines(long addr)
1189 {
1190         line_t *lp, *np = get_addressed_line_node(first_addr);
1191         undo_t *up = NULL;
1192         long n = second_addr - first_addr + 1;
1193         long m = 0;
1194
1195         current_addr = addr;
1196         if (first_addr <= addr && addr < second_addr) {
1197                 n =  addr - first_addr + 1;
1198                 m = second_addr - addr;
1199         }
1200         for (; n > 0; n=m, m=0, np = get_addressed_line_node(current_addr + 1))
1201                 for (; n-- > 0; np = np->q_forw) {
1202                         SPL1();
1203                         if ((lp = dup_line_node(np)) == NULL) {
1204                                 SPL0();
1205                                 return ERR;
1206                         }
1207                         add_line_node(lp);
1208                         if (up)
1209                                 up->t = lp;
1210                         else if ((up = push_undo_stack(UADD, current_addr,
1211                             current_addr)) == NULL) {
1212                                 SPL0();
1213                                 return ERR;
1214                         }
1215                         modified = 1;
1216                         SPL0();
1217                 }
1218         return 0;
1219 }
1220
1221
1222 /* delete_lines: delete a range of lines */
1223 int
1224 delete_lines(long from, long to)
1225 {
1226         line_t *n, *p;
1227
1228         SPL1();
1229         if (push_undo_stack(UDEL, from, to) == NULL) {
1230                 SPL0();
1231                 return ERR;
1232         }
1233         n = get_addressed_line_node(INC_MOD(to, addr_last));
1234         p = get_addressed_line_node(from - 1);
1235                                         /* this get_addressed_line_node last! */
1236         if (isglobal)
1237                 unset_active_nodes(p->q_forw, n);
1238         REQUE(p, n);
1239         addr_last -= to - from + 1;
1240         current_addr = from - 1;
1241         modified = 1;
1242         SPL0();
1243         return 0;
1244 }
1245
1246
1247 /* display_lines: print a range of lines to stdout */
1248 int
1249 display_lines(long from, long to, int gflag)
1250 {
1251         line_t *bp;
1252         line_t *ep;
1253         char *s;
1254
1255         if (!from) {
1256                 errmsg = "invalid address";
1257                 return ERR;
1258         }
1259         ep = get_addressed_line_node(INC_MOD(to, addr_last));
1260         bp = get_addressed_line_node(from);
1261         for (; bp != ep; bp = bp->q_forw) {
1262                 if ((s = get_sbuf_line(bp)) == NULL)
1263                         return ERR;
1264                 if (put_tty_line(s, bp->len, current_addr = from++, gflag) < 0)
1265                         return ERR;
1266         }
1267         return 0;
1268 }
1269
1270
1271 #define MAXMARK 26                      /* max number of marks */
1272
1273 line_t  *mark[MAXMARK];                 /* line markers */
1274 int markno;                             /* line marker count */
1275
1276 /* mark_line_node: set a line node mark */
1277 int
1278 mark_line_node(line_t *lp, int n)
1279 {
1280         if (!islower((unsigned char)n)) {
1281                 errmsg = "invalid mark character";
1282                 return ERR;
1283         } else if (mark[n - 'a'] == NULL)
1284                 markno++;
1285         mark[n - 'a'] = lp;
1286         return 0;
1287 }
1288
1289
1290 /* get_marked_node_addr: return address of a marked line */
1291 long
1292 get_marked_node_addr(int n)
1293 {
1294         if (!islower((unsigned char)n)) {
1295                 errmsg = "invalid mark character";
1296                 return ERR;
1297         }
1298         return get_line_node_addr(mark[n - 'a']);
1299 }
1300
1301 /* Used by search and replace */
1302 void
1303 replace_marks(line_t *old, line_t *new)
1304 {
1305         int i;
1306         for (i=0; markno && i<MAXMARK; i++)
1307                 if (mark[i] == old)
1308                         mark[i] = new;
1309 }
1310
1311
1312 /* unmark_line_node: clear line node mark */
1313 void
1314 unmark_line_node(line_t *lp)
1315 {
1316         int i;
1317
1318         for (i = 0; markno && i < MAXMARK; i++)
1319                 if (mark[i] == lp) {
1320                         mark[i] = NULL;
1321                         markno--;
1322                 }
1323 }
1324
1325
1326 /* dup_line_node: return a pointer to a copy of a line node */
1327 line_t *
1328 dup_line_node(line_t *lp)
1329 {
1330         line_t *np;
1331
1332         if ((np = (line_t *) malloc(sizeof(line_t))) == NULL) {
1333                 fprintf(stderr, "%s\n", strerror(errno));
1334                 errmsg = "out of memory";
1335                 return NULL;
1336         }
1337         np->seek = lp->seek;
1338         np->len = lp->len;
1339         return np;
1340 }
1341
1342
1343 /* has_trailing_escape:  return the parity of escapes preceding a character
1344    in a string */
1345 int
1346 has_trailing_escape(char *s, char *t)
1347 {
1348     return (s == t || *(t - 1) != '\\') ? 0 : !has_trailing_escape(s, t - 1);
1349 }
1350
1351
1352 /* strip_escapes: return copy of escaped string of at most length PATH_MAX */
1353 char *
1354 strip_escapes(char *s)
1355 {
1356         static char *file = NULL;
1357         static int filesz = 0;
1358
1359         int i = 0;
1360
1361         REALLOC(file, filesz, PATH_MAX, NULL);
1362         while (i < filesz - 1   /* Worry about a possible trailing escape */
1363                && (file[i++] = (*s == '\\') ? *++s : *s))
1364                 s++;
1365         return file;
1366 }
1367
1368
1369 void
1370 signal_hup(int signo)
1371 {
1372         if (mutex)
1373                 sigflags |= (1 << (signo - 1));
1374         else
1375                 handle_hup(signo);
1376 }
1377
1378
1379 void
1380 signal_int(int signo)
1381 {
1382         if (mutex)
1383                 sigflags |= (1 << (signo - 1));
1384         else
1385                 handle_int(signo);
1386 }
1387
1388
1389 void
1390 handle_hup(int signo)
1391 {
1392         char *hup = NULL;               /* hup filename */
1393         char *s;
1394         char ed_hup[] = "ed.hup";
1395         int n;
1396
1397         if (!sigactive)
1398                 quit(1);
1399         sigflags &= ~(1 << (signo - 1));
1400         if (addr_last && write_file(ed_hup, "w", 1, addr_last) < 0 &&
1401             (s = getenv("HOME")) != NULL &&
1402             (n = strlen(s)) + 8 <= PATH_MAX &&  /* "ed.hup" + '/' */
1403             (hup = (char *) malloc(n + 10)) != NULL) {
1404                 strcpy(hup, s);
1405                 if (hup[n - 1] != '/')
1406                         hup[n] = '/', hup[n+1] = '\0';
1407                 strcat(hup, "ed.hup");
1408                 write_file(hup, "w", 1, addr_last);
1409         }
1410         quit(2);
1411 }
1412
1413
1414 void
1415 handle_int(int signo)
1416 {
1417         if (!sigactive)
1418                 quit(1);
1419         sigflags &= ~(1 << (signo - 1));
1420 #ifdef _POSIX_SOURCE
1421         siglongjmp(env, -1);
1422 #else
1423         longjmp(env, -1);
1424 #endif
1425 }
1426
1427
1428 int cols = 72;                          /* wrap column */
1429
1430 void
1431 handle_winch(int signo)
1432 {
1433         int save_errno = errno;
1434
1435         struct winsize ws;              /* window size structure */
1436
1437         sigflags &= ~(1 << (signo - 1));
1438         if (ioctl(0, TIOCGWINSZ, (char *) &ws) >= 0) {
1439                 if (ws.ws_row > 2) rows = ws.ws_row - 2;
1440                 if (ws.ws_col > 8) cols = ws.ws_col - 8;
1441         }
1442         errno = save_errno;
1443 }
1444
1445
1446 /* is_legal_filename: return a legal filename */
1447 int
1448 is_legal_filename(char *s)
1449 {
1450         if (red && (*s == '!' || !strcmp(s, "..") || strchr(s, '/'))) {
1451                 errmsg = "shell access restricted";
1452                 return 0;
1453         }
1454         return 1;
1455 }