bin/ed/main.c

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