bin/ed/main.c

   1 /* main.c: This file contains the main control and user-interface routines
   2    for the ed line editor. */
   3 /*-
   4  * Copyright (c) 1993 Andrew Moore, Talke Studio.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  *
  28  * @(#) Copyright (c) 1993 Andrew Moore, Talke Studio. All rights reserved.
  29  * @(#)main.c,v 1.1 1994/02/01 00:34:42 alm Exp
  30  * $FreeBSD: head/bin/ed/main.c 292455 2015-12-18 23:05:36Z pfg $
  31  */
  32
  33 /*
  34  * CREDITS
  35  *
  36  *      This program is based on the editor algorithm described in
  37  *      Brian W. Kernighan and P. J. Plauger's book "Software Tools
  38  *      in Pascal," Addison-Wesley, 1981.
  39  *
  40  *      The buffering algorithm is attributed to Rodney Ruddock of
  41  *      the University of Guelph, Guelph, Ontario.
  42  *
  43  *      The cbc.c encryption code is adapted from
  44  *      the bdes program by Matt Bishop of Dartmouth College,
  45  *      Hanover, NH.
  46  *
  47  */
  48
  49 #include <sys/types.h>
  50
  51 #include <sys/ioctl.h>
  52 #include <sys/wait.h>
  53 #include <ctype.h>
  54 #include <locale.h>
  55 #include <pwd.h>
  56 #include <setjmp.h>
  57
  58 #include "ed.h"
  59
  60
  61 static sigjmp_buf env;
  62
  63 /* static buffers */
  64 char stdinbuf[1];               /* stdin buffer */
  65 static char *shcmd;             /* shell command buffer */
  66 static int shcmdsz;             /* shell command buffer size */
  67 static int shcmdi;              /* shell command buffer index */
  68 char *ibuf;                     /* ed command-line buffer */
  69 int ibufsz;                     /* ed command-line buffer size */
  70 char *ibufp;                    /* pointer to ed command-line buffer */
  71
  72 /* global flags */
  73 int des = 0;                    /* if set, use crypt(3) for i/o */
  74 static int garrulous = 0;       /* if set, print all error messages */
  75 int isbinary;                   /* if set, buffer contains ASCII NULs */
  76 int isglobal;                   /* if set, doing a global command */
  77 int modified;                   /* if set, buffer modified since last write */
  78 int mutex = 0;                  /* if set, signals set "sigflags" */
  79 static int red = 0;             /* if set, restrict shell/directory access */
  80 int scripted = 0;               /* if set, suppress diagnostics */
  81 int sigflags = 0;               /* if set, signals received while mutex set */
  82 static int sigactive = 0;       /* if set, signal handlers are enabled */
  83
  84 static char old_filename[PATH_MAX] = ""; /* default filename */
  85 long current_addr;              /* current address in editor buffer */
  86 long addr_last;                 /* last address in editor buffer */
  87 int lineno;                     /* script line number */
  88 static const char *prompt;      /* command-line prompt */
  89 static const char *dps = "*";   /* default command-line prompt */
  90
  91 static const char *usage = "usage: %s [-] [-sx] [-p string] [file]\n";
  92
  93 /* ed: line editor */
  94 int
  95 main(volatile int argc, char ** volatile argv)
  96 {
  97         int c, n;
  98         long status = 0;
  99
 100         setlocale(LC_ALL, "");
 101
 102         red = (n = strlen(argv[0])) > 2 && argv[0][n - 3] == 'r';
 103 top:
 104         while ((c = getopt(argc, argv, "p:sx")) != -1)
 105                 switch(c) {
 106                 case 'p':                               /* set prompt */
 107                         prompt = optarg;
 108                         break;
 109                 case 's':                               /* run script */
 110                         scripted = 1;
 111                         break;
 112                 case 'x':                               /* use crypt */
 113 #ifdef DES
 114                         des = get_keyword();
 115 #else
 116                         fprintf(stderr, "crypt unavailable\n?\n");
 117 #endif
 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         if ((status = sigsetjmp(env, 1))) {
 144                 fputs("\n?\n", stderr);
 145                 errmsg = "interrupt";
 146         } else {
 147                 init_buffers();
 148                 sigactive = 1;                  /* enable signal handlers */
 149                 if (argc && **argv && is_legal_filename(*argv)) {
 150                         if (read_file(*argv, 0) < 0 && !isatty(0))
 151                                 quit(2);
 152                         else if (**argv != '!')
 153                                 if (strlcpy(old_filename, *argv, sizeof(old_filename))
 154                                     >= sizeof(old_filename))
 155                                         quit(2);
 156                 } else if (argc) {
 157                         fputs("?\n", stderr);
 158                         if (**argv == '\0')
 159                                 errmsg = "invalid filename";
 160                         if (!isatty(0))
 161                                 quit(2);
 162                 }
 163         }
 164         for (;;) {
 165                 if (status < 0 && garrulous)
 166                         fprintf(stderr, "%s\n", errmsg);
 167                 if (prompt) {
 168                         printf("%s", prompt);
 169                         fflush(stdout);
 170                 }
 171                 if ((n = get_tty_line()) < 0) {
 172                         status = ERR;
 173                         continue;
 174                 } else if (n == 0) {
 175                         if (modified && !scripted) {
 176                                 fputs("?\n", stderr);
 177                                 errmsg = "warning: file modified";
 178                                 if (!isatty(0)) {
 179                                         if (garrulous)
 180                                                 fprintf(stderr,
 181                                                     "script, line %d: %s\n",
 182                                                     lineno, errmsg);
 183                                         quit(2);
 184                                 }
 185                                 clearerr(stdin);
 186                                 modified = 0;
 187                                 status = EMOD;
 188                                 continue;
 189                         } else
 190                                 quit(0);
 191                 } else if (ibuf[n - 1] != '\n') {
 192                         /* discard line */
 193                         errmsg = "unexpected end-of-file";
 194                         clearerr(stdin);
 195                         status = ERR;
 196                         continue;
 197                 }
 198                 isglobal = 0;
 199                 if ((status = extract_addr_range()) >= 0 &&
 200                     (status = exec_command()) >= 0)
 201                         if (!status ||
 202                             (status = display_lines(current_addr, current_addr,
 203                                 status)) >= 0)
 204                                 continue;
 205                 switch (status) {
 206                 case EOF:
 207                         quit(0);
 208                 case EMOD:
 209                         modified = 0;
 210                         fputs("?\n", stderr);           /* give warning */
 211                         errmsg = "warning: file modified";
 212                         if (!isatty(0)) {
 213                                 if (garrulous)
 214                                         fprintf(stderr, "script, line %d: %s\n",
 215                                             lineno, errmsg);
 216                                 quit(2);
 217                         }
 218                         break;
 219                 case FATAL:
 220                         if (!isatty(0)) {
 221                                 if (garrulous)
 222                                         fprintf(stderr, "script, line %d: %s\n",
 223                                             lineno, errmsg);
 224                         } else if (garrulous)
 225                                 fprintf(stderr, "%s\n", errmsg);
 226                         quit(3);
 227                 default:
 228                         fputs("?\n", stderr);
 229                         if (!isatty(0)) {
 230                                 if (garrulous)
 231                                         fprintf(stderr, "script, line %d: %s\n",
 232                                             lineno, errmsg);
 233                                 quit(2);
 234                         }
 235                         break;
 236                 }
 237         }
 238         /*NOTREACHED*/
 239 }
 240
 241 long first_addr, second_addr;
 242 static long addr_cnt;
 243
 244 /* extract_addr_range: get line addresses from the command buffer until an
 245    illegal address is seen; return status */
 246 int
 247 extract_addr_range(void)
 248 {
 249         long addr;
 250
 251         addr_cnt = 0;
 252         first_addr = second_addr = current_addr;
 253         while ((addr = next_addr()) >= 0) {
 254                 addr_cnt++;
 255                 first_addr = second_addr;
 256                 second_addr = addr;
 257                 if (*ibufp != ',' && *ibufp != ';')
 258                         break;
 259                 else if (*ibufp++ == ';')
 260                         current_addr = addr;
 261         }
 262         if ((addr_cnt = min(addr_cnt, 2)) == 1 || second_addr != addr)
 263                 first_addr = second_addr;
 264         return (addr == ERR) ? ERR : 0;
 265 }
 266
 267
 268 #define SKIP_BLANKS() while (isspace((unsigned char)*ibufp) && *ibufp != '\n') ibufp++
 269
 270 #define MUST_BE_FIRST() do {                                    \
 271         if (!first) {                                           \
 272                 errmsg = "invalid address";                     \
 273                 return ERR;                                     \
 274         }                                                       \
 275 } while (0)
 276
 277 /*  next_addr: return the next line address in the command buffer */
 278 long
 279 next_addr(void)
 280 {
 281         const char *hd;
 282         long addr = current_addr;
 283         long n;
 284         int first = 1;
 285         int c;
 286
 287         SKIP_BLANKS();
 288         for (hd = ibufp;; first = 0)
 289                 switch (c = *ibufp) {
 290                 case '+':
 291                 case '\t':
 292                 case ' ':
 293                 case '-':
 294                 case '^':
 295                         ibufp++;
 296                         SKIP_BLANKS();
 297                         if (isdigit((unsigned char)*ibufp)) {
 298                                 STRTOL(n, ibufp);
 299                                 addr += (c == '-' || c == '^') ? -n : n;
 300                         } else if (!isspace((unsigned char)c))
 301                                 addr += (c == '-' || c == '^') ? -1 : 1;
 302                         break;
 303                 case '0': case '1': case '2':
 304                 case '3': case '4': case '5':
 305                 case '6': case '7': case '8': case '9':
 306                         MUST_BE_FIRST();
 307                         STRTOL(addr, ibufp);
 308                         break;
 309                 case '.':
 310                 case '$':
 311                         MUST_BE_FIRST();
 312                         ibufp++;
 313                         addr = (c == '.') ? current_addr : addr_last;
 314                         break;
 315                 case '/':
 316                 case '?':
 317                         MUST_BE_FIRST();
 318                         if ((addr = get_matching_node_addr(
 319                             get_compiled_pattern(), c == '/')) < 0)
 320                                 return ERR;
 321                         else if (c == *ibufp)
 322                                 ibufp++;
 323                         break;
 324                 case '\'':
 325                         MUST_BE_FIRST();
 326                         ibufp++;
 327                         if ((addr = get_marked_node_addr(*ibufp++)) < 0)
 328                                 return ERR;
 329                         break;
 330                 case '%':
 331                 case ',':
 332                 case ';':
 333                         if (first) {
 334                                 ibufp++;
 335                                 addr_cnt++;
 336                                 second_addr = (c == ';') ? current_addr : 1;
 337                                 addr = addr_last;
 338                                 break;
 339                         }
 340                         /* FALLTHROUGH */
 341                 default:
 342                         if (ibufp == hd)
 343                                 return EOF;
 344                         else if (addr < 0 || addr_last < addr) {
 345                                 errmsg = "invalid address";
 346                                 return ERR;
 347                         } else
 348                                 return addr;
 349                 }
 350         /* NOTREACHED */
 351 }
 352
 353
 354 #ifdef BACKWARDS
 355 /* GET_THIRD_ADDR: get a legal address from the command buffer */
 356 #define GET_THIRD_ADDR(addr) \
 357 { \
 358         long ol1, ol2; \
 359 \
 360         ol1 = first_addr, ol2 = second_addr; \
 361         if (extract_addr_range() < 0) \
 362                 return ERR; \
 363         else if (addr_cnt == 0) { \
 364                 errmsg = "destination expected"; \
 365                 return ERR; \
 366         } else if (second_addr < 0 || addr_last < second_addr) { \
 367                 errmsg = "invalid address"; \
 368                 return ERR; \
 369         } \
 370         addr = second_addr; \
 371         first_addr = ol1, second_addr = ol2; \
 372 }
 373 #else   /* BACKWARDS */
 374 /* GET_THIRD_ADDR: get a legal address from the command buffer */
 375 #define GET_THIRD_ADDR(addr) \
 376 { \
 377         long ol1, ol2; \
 378 \
 379         ol1 = first_addr, ol2 = second_addr; \
 380         if (extract_addr_range() < 0) \
 381                 return ERR; \
 382         if (second_addr < 0 || addr_last < second_addr) { \
 383                 errmsg = "invalid address"; \
 384                 return ERR; \
 385         } \
 386         addr = second_addr; \
 387         first_addr = ol1, second_addr = ol2; \
 388 }
 389 #endif
 390
 391
 392 /* GET_COMMAND_SUFFIX: verify the command suffix in the command buffer */
 393 #define GET_COMMAND_SUFFIX() { \
 394         int done = 0; \
 395         do { \
 396                 switch(*ibufp) { \
 397                 case 'p': \
 398                         gflag |= GPR, ibufp++; \
 399                         break; \
 400                 case 'l': \
 401                         gflag |= GLS, ibufp++; \
 402                         break; \
 403                 case 'n': \
 404                         gflag |= GNP, ibufp++; \
 405                         break; \
 406                 default: \
 407                         done++; \
 408                 } \
 409         } while (!done); \
 410         if (*ibufp++ != '\n') { \
 411                 errmsg = "invalid command suffix"; \
 412                 return ERR; \
 413         } \
 414 }
 415
 416
 417 /* sflags */
 418 #define SGG 001         /* complement previous global substitute suffix */
 419 #define SGP 002         /* complement previous print suffix */
 420 #define SGR 004         /* use last regex instead of last pat */
 421 #define SGF 010         /* repeat last substitution */
 422
 423 int patlock = 0;        /* if set, pattern not freed by get_compiled_pattern() */
 424
 425 long rows = 22;         /* scroll length: ws_row - 2 */
 426
 427 /* exec_command: execute the next command in command buffer; return print
 428    request, if any */
 429 int
 430 exec_command(void)
 431 {
 432         static pattern_t *pat = NULL;
 433         static int sgflag = 0;
 434         static long sgnum = 0;
 435
 436         pattern_t *tpat;
 437         char *fnp;
 438         int gflag = 0;
 439         int sflags = 0;
 440         long addr = 0;
 441         int n = 0;
 442         int c;
 443
 444         SKIP_BLANKS();
 445         switch(c = *ibufp++) {
 446         case 'a':
 447                 GET_COMMAND_SUFFIX();
 448                 if (!isglobal) clear_undo_stack();
 449                 if (append_lines(second_addr) < 0)
 450                         return ERR;
 451                 break;
 452         case 'c':
 453                 if (check_addr_range(current_addr, current_addr) < 0)
 454                         return ERR;
 455                 GET_COMMAND_SUFFIX();
 456                 if (!isglobal) clear_undo_stack();
 457                 if (delete_lines(first_addr, second_addr) < 0 ||
 458                     append_lines(current_addr) < 0)
 459                         return ERR;
 460                 break;
 461         case 'd':
 462                 if (check_addr_range(current_addr, current_addr) < 0)
 463                         return ERR;
 464                 GET_COMMAND_SUFFIX();
 465                 if (!isglobal) clear_undo_stack();
 466                 if (delete_lines(first_addr, second_addr) < 0)
 467                         return ERR;
 468                 else if ((addr = INC_MOD(current_addr, addr_last)) != 0)
 469                         current_addr = addr;
 470                 break;
 471         case 'e':
 472                 if (modified && !scripted)
 473                         return EMOD;
 474                 /* FALLTHROUGH */
 475         case 'E':
 476                 if (addr_cnt > 0) {
 477                         errmsg = "unexpected address";
 478                         return ERR;
 479                 } else if (!isspace((unsigned char)*ibufp)) {
 480                         errmsg = "unexpected command suffix";
 481                         return ERR;
 482                 } else if ((fnp = get_filename()) == NULL)
 483                         return ERR;
 484                 GET_COMMAND_SUFFIX();
 485                 if (delete_lines(1, addr_last) < 0)
 486                         return ERR;
 487                 clear_undo_stack();
 488                 if (close_sbuf() < 0)
 489                         return ERR;
 490                 else if (open_sbuf() < 0)
 491                         return FATAL;
 492                 if (*fnp && *fnp != '!')
 493                          strlcpy(old_filename, fnp, PATH_MAX);
 494 #ifdef BACKWARDS
 495                 if (*fnp == '\0' && *old_filename == '\0') {
 496                         errmsg = "no current filename";
 497                         return ERR;
 498                 }
 499 #endif
 500                 if (read_file(*fnp ? fnp : old_filename, 0) < 0)
 501                         return ERR;
 502                 clear_undo_stack();
 503                 modified = 0;
 504                 u_current_addr = u_addr_last = -1;
 505                 break;
 506         case 'f':
 507                 if (addr_cnt > 0) {
 508                         errmsg = "unexpected address";
 509                         return ERR;
 510                 } else if (!isspace((unsigned char)*ibufp)) {
 511                         errmsg = "unexpected command suffix";
 512                         return ERR;
 513                 } else if ((fnp = get_filename()) == NULL)
 514                         return ERR;
 515                 else if (*fnp == '!') {
 516                         errmsg = "invalid redirection";
 517                         return ERR;
 518                 }
 519                 GET_COMMAND_SUFFIX();
 520                 if (*fnp)
 521                         strlcpy(old_filename, fnp, PATH_MAX);
 522                 printf("%s\n", strip_escapes(old_filename));
 523                 break;
 524         case 'g':
 525         case 'v':
 526         case 'G':
 527         case 'V':
 528                 if (isglobal) {
 529                         errmsg = "cannot nest global commands";
 530                         return ERR;
 531                 } else if (check_addr_range(1, addr_last) < 0)
 532                         return ERR;
 533                 else if (build_active_list(c == 'g' || c == 'G') < 0)
 534                         return ERR;
 535                 else if ((n = (c == 'G' || c == 'V')))
 536                         GET_COMMAND_SUFFIX();
 537                 isglobal++;
 538                 if (exec_global(n, gflag) < 0)
 539                         return ERR;
 540                 break;
 541         case 'h':
 542                 if (addr_cnt > 0) {
 543                         errmsg = "unexpected address";
 544                         return ERR;
 545                 }
 546                 GET_COMMAND_SUFFIX();
 547                 if (*errmsg) fprintf(stderr, "%s\n", errmsg);
 548                 break;
 549         case 'H':
 550                 if (addr_cnt > 0) {
 551                         errmsg = "unexpected address";
 552                         return ERR;
 553                 }
 554                 GET_COMMAND_SUFFIX();
 555                 if ((garrulous = 1 - garrulous) && *errmsg)
 556                         fprintf(stderr, "%s\n", errmsg);
 557                 break;
 558         case 'i':
 559                 if (second_addr == 0) {
 560                         errmsg = "invalid address";
 561                         return ERR;
 562                 }
 563                 GET_COMMAND_SUFFIX();
 564                 if (!isglobal) clear_undo_stack();
 565                 if (append_lines(second_addr - 1) < 0)
 566                         return ERR;
 567                 break;
 568         case 'j':
 569                 if (check_addr_range(current_addr, current_addr + 1) < 0)
 570                         return ERR;
 571                 GET_COMMAND_SUFFIX();
 572                 if (!isglobal) clear_undo_stack();
 573                 if (first_addr != second_addr &&
 574                     join_lines(first_addr, second_addr) < 0)
 575                         return ERR;
 576                 break;
 577         case 'k':
 578                 c = *ibufp++;
 579                 if (second_addr == 0) {
 580                         errmsg = "invalid address";
 581                         return ERR;
 582                 }
 583                 GET_COMMAND_SUFFIX();
 584                 if (mark_line_node(get_addressed_line_node(second_addr), c) < 0)
 585                         return ERR;
 586                 break;
 587         case 'l':
 588                 if (check_addr_range(current_addr, current_addr) < 0)
 589                         return ERR;
 590                 GET_COMMAND_SUFFIX();
 591                 if (display_lines(first_addr, second_addr, gflag | GLS) < 0)
 592                         return ERR;
 593                 gflag = 0;
 594                 break;
 595         case 'm':
 596                 if (check_addr_range(current_addr, current_addr) < 0)
 597                         return ERR;
 598                 GET_THIRD_ADDR(addr);
 599                 if (first_addr <= addr && addr < second_addr) {
 600                         errmsg = "invalid destination";
 601                         return ERR;
 602                 }
 603                 GET_COMMAND_SUFFIX();
 604                 if (!isglobal) clear_undo_stack();
 605                 if (move_lines(addr) < 0)
 606                         return ERR;
 607                 break;
 608         case 'n':
 609                 if (check_addr_range(current_addr, current_addr) < 0)
 610                         return ERR;
 611                 GET_COMMAND_SUFFIX();
 612                 if (display_lines(first_addr, second_addr, gflag | GNP) < 0)
 613                         return ERR;
 614                 gflag = 0;
 615                 break;
 616         case 'p':
 617                 if (check_addr_range(current_addr, current_addr) < 0)
 618                         return ERR;
 619                 GET_COMMAND_SUFFIX();
 620                 if (display_lines(first_addr, second_addr, gflag | GPR) < 0)
 621                         return ERR;
 622                 gflag = 0;
 623                 break;
 624         case 'P':
 625                 if (addr_cnt > 0) {
 626                         errmsg = "unexpected address";
 627                         return ERR;
 628                 }
 629                 GET_COMMAND_SUFFIX();
 630                 prompt = prompt ? NULL : optarg ? optarg : dps;
 631                 break;
 632         case 'q':
 633         case 'Q':
 634                 if (addr_cnt > 0) {
 635                         errmsg = "unexpected address";
 636                         return ERR;
 637                 }
 638                 GET_COMMAND_SUFFIX();
 639                 gflag =  (modified && !scripted && c == 'q') ? EMOD : EOF;
 640                 break;
 641         case 'r':
 642                 if (!isspace((unsigned char)*ibufp)) {
 643                         errmsg = "unexpected command suffix";
 644                         return ERR;
 645                 } else if (addr_cnt == 0)
 646                         second_addr = addr_last;
 647                 if ((fnp = get_filename()) == NULL)
 648                         return ERR;
 649                 GET_COMMAND_SUFFIX();
 650                 if (!isglobal) clear_undo_stack();
 651                 if (*old_filename == '\0' && *fnp != '!')
 652                         strlcpy(old_filename, fnp, PATH_MAX);
 653 #ifdef BACKWARDS
 654                 if (*fnp == '\0' && *old_filename == '\0') {
 655                         errmsg = "no current filename";
 656                         return ERR;
 657                 }
 658 #endif
 659                 if ((addr = read_file(*fnp ? fnp : old_filename, second_addr)) < 0)
 660                         return ERR;
 661                 else if (addr && addr != addr_last)
 662                         modified = 1;
 663                 break;
 664         case 's':
 665                 do {
 666                         switch(*ibufp) {
 667                         case '\n':
 668                                 sflags |=SGF;
 669                                 break;
 670                         case 'g':
 671                                 sflags |= SGG;
 672                                 ibufp++;
 673                                 break;
 674                         case 'p':
 675                                 sflags |= SGP;
 676                                 ibufp++;
 677                                 break;
 678                         case 'r':
 679                                 sflags |= SGR;
 680                                 ibufp++;
 681                                 break;
 682                         case '0': case '1': case '2': case '3': case '4':
 683                         case '5': case '6': case '7': case '8': case '9':
 684                                 STRTOL(sgnum, ibufp);
 685                                 sflags |= SGF;
 686                                 sgflag &= ~GSG;         /* override GSG */
 687                                 break;
 688                         default:
 689                                 if (sflags) {
 690                                         errmsg = "invalid command suffix";
 691                                         return ERR;
 692                                 }
 693                         }
 694                 } while (sflags && *ibufp != '\n');
 695                 if (sflags && !pat) {
 696                         errmsg = "no previous substitution";
 697                         return ERR;
 698                 } else if (sflags & SGG)
 699                         sgnum = 0;              /* override numeric arg */
 700                 if (*ibufp != '\n' && *(ibufp + 1) == '\n') {
 701                         errmsg = "invalid pattern delimiter";
 702                         return ERR;
 703                 }
 704                 tpat = pat;
 705                 SPL1();
 706                 if ((!sflags || (sflags & SGR)) &&
 707                     (tpat = get_compiled_pattern()) == NULL) {
 708                         SPL0();
 709                         return ERR;
 710                 } else if (tpat != pat) {
 711                         if (pat) {
 712                                 regfree(pat);
 713                                 free(pat);
 714                         }
 715                         pat = tpat;
 716                         patlock = 1;            /* reserve pattern */
 717                 }
 718                 SPL0();
 719                 if (!sflags && extract_subst_tail(&sgflag, &sgnum) < 0)
 720                         return ERR;
 721                 else if (isglobal)
 722                         sgflag |= GLB;
 723                 else
 724                         sgflag &= ~GLB;
 725                 if (sflags & SGG)
 726                         sgflag ^= GSG;
 727                 if (sflags & SGP)
 728                         sgflag ^= GPR, sgflag &= ~(GLS | GNP);
 729                 do {
 730                         switch(*ibufp) {
 731                         case 'p':
 732                                 sgflag |= GPR, ibufp++;
 733                                 break;
 734                         case 'l':
 735                                 sgflag |= GLS, ibufp++;
 736                                 break;
 737                         case 'n':
 738                                 sgflag |= GNP, ibufp++;
 739                                 break;
 740                         default:
 741                                 n++;
 742                         }
 743                 } while (!n);
 744                 if (check_addr_range(current_addr, current_addr) < 0)
 745                         return ERR;
 746                 GET_COMMAND_SUFFIX();
 747                 if (!isglobal) clear_undo_stack();
 748                 if (search_and_replace(pat, sgflag, sgnum) < 0)
 749                         return ERR;
 750                 break;
 751         case 't':
 752                 if (check_addr_range(current_addr, current_addr) < 0)
 753                         return ERR;
 754                 GET_THIRD_ADDR(addr);
 755                 GET_COMMAND_SUFFIX();
 756                 if (!isglobal) clear_undo_stack();
 757                 if (copy_lines(addr) < 0)
 758                         return ERR;
 759                 break;
 760         case 'u':
 761                 if (addr_cnt > 0) {
 762                         errmsg = "unexpected address";
 763                         return ERR;
 764                 }
 765                 GET_COMMAND_SUFFIX();
 766                 if (pop_undo_stack() < 0)
 767                         return ERR;
 768                 break;
 769         case 'w':
 770         case 'W':
 771                 if ((n = *ibufp) == 'q' || n == 'Q') {
 772                         gflag = EOF;
 773                         ibufp++;
 774                 }
 775                 if (!isspace((unsigned char)*ibufp)) {
 776                         errmsg = "unexpected command suffix";
 777                         return ERR;
 778                 } else if ((fnp = get_filename()) == NULL)
 779                         return ERR;
 780                 if (addr_cnt == 0 && !addr_last)
 781                         first_addr = second_addr = 0;
 782                 else if (check_addr_range(1, addr_last) < 0)
 783                         return ERR;
 784                 GET_COMMAND_SUFFIX();
 785                 if (*old_filename == '\0' && *fnp != '!')
 786                         strlcpy(old_filename, fnp, PATH_MAX);
 787 #ifdef BACKWARDS
 788                 if (*fnp == '\0' && *old_filename == '\0') {
 789                         errmsg = "no current filename";
 790                         return ERR;
 791                 }
 792 #endif
 793                 if ((addr = write_file(*fnp ? fnp : old_filename,
 794                     (c == 'W') ? "a" : "w", first_addr, second_addr)) < 0)
 795                         return ERR;
 796                 else if (addr == addr_last)
 797                         modified = 0;
 798                 else if (modified && !scripted && n == 'q')
 799                         gflag = EMOD;
 800                 break;
 801         case 'x':
 802                 if (addr_cnt > 0) {
 803                         errmsg = "unexpected address";
 804                         return ERR;
 805                 }
 806                 GET_COMMAND_SUFFIX();
 807 #ifdef DES
 808                 des = get_keyword();
 809                 break;
 810 #else
 811                 errmsg = "crypt unavailable";
 812                 return ERR;
 813 #endif
 814         case 'z':
 815 #ifdef BACKWARDS
 816                 if (check_addr_range(first_addr = 1, current_addr + 1) < 0)
 817 #else
 818                 if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0)
 819 #endif
 820                         return ERR;
 821                 else if ('0' < *ibufp && *ibufp <= '9')
 822                         STRTOL(rows, ibufp);
 823                 GET_COMMAND_SUFFIX();
 824                 if (display_lines(second_addr, min(addr_last,
 825                     second_addr + rows), gflag) < 0)
 826                         return ERR;
 827                 gflag = 0;
 828                 break;
 829         case '=':
 830                 GET_COMMAND_SUFFIX();
 831                 printf("%ld\n", addr_cnt ? second_addr : addr_last);
 832                 break;
 833         case '!':
 834                 if (addr_cnt > 0) {
 835                         errmsg = "unexpected address";
 836                         return ERR;
 837                 } else if ((sflags = get_shell_command()) < 0)
 838                         return ERR;
 839                 GET_COMMAND_SUFFIX();
 840                 if (sflags) printf("%s\n", shcmd + 1);
 841                 system(shcmd + 1);
 842                 if (!scripted) printf("!\n");
 843                 break;
 844         case '\n':
 845 #ifdef BACKWARDS
 846                 if (check_addr_range(first_addr = 1, current_addr + 1) < 0
 847 #else
 848                 if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0
 849 #endif
 850                  || display_lines(second_addr, second_addr, 0) < 0)
 851                         return ERR;
 852                 break;
 853         default:
 854                 errmsg = "unknown command";
 855                 return ERR;
 856         }
 857         return gflag;
 858 }
 859
 860
 861 /* check_addr_range: return status of address range check */
 862 int
 863 check_addr_range(long n, long m)
 864 {
 865         if (addr_cnt == 0) {
 866                 first_addr = n;
 867                 second_addr = m;
 868         }
 869         if (first_addr > second_addr || 1 > first_addr ||
 870             second_addr > addr_last) {
 871                 errmsg = "invalid address";
 872                 return ERR;
 873         }
 874         return 0;
 875 }
 876
 877
 878 /* get_matching_node_addr: return the address of the next line matching a
 879    pattern in a given direction.  wrap around begin/end of editor buffer if
 880    necessary */
 881 long
 882 get_matching_node_addr(pattern_t *pat, int dir)
 883 {
 884         char *s;
 885         long n = current_addr;
 886         line_t *lp;
 887
 888         if (!pat) return ERR;
 889         do {
 890                if ((n = dir ? INC_MOD(n, addr_last) : DEC_MOD(n, addr_last))) {
 891                         lp = get_addressed_line_node(n);
 892                         if ((s = get_sbuf_line(lp)) == NULL)
 893                                 return ERR;
 894                         if (isbinary)
 895                                 NUL_TO_NEWLINE(s, lp->len);
 896                         if (!regexec(pat, s, 0, NULL, 0))
 897                                 return n;
 898                }
 899         } while (n != current_addr);
 900         errmsg = "no match";
 901         return  ERR;
 902 }
 903
 904
 905 /* get_filename: return pointer to copy of filename in the command buffer */
 906 char *
 907 get_filename(void)
 908 {
 909         static char *file = NULL;
 910         static int filesz = 0;
 911
 912         int n;
 913
 914         if (*ibufp != '\n') {
 915                 SKIP_BLANKS();
 916                 if (*ibufp == '\n') {
 917                         errmsg = "invalid filename";
 918                         return NULL;
 919                 } else if ((ibufp = get_extended_line(&n, 1)) == NULL)
 920                         return NULL;
 921                 else if (*ibufp == '!') {
 922                         ibufp++;
 923                         if ((n = get_shell_command()) < 0)
 924                                 return NULL;
 925                         if (n)
 926                                 printf("%s\n", shcmd + 1);
 927                         return shcmd;
 928                 } else if (n > PATH_MAX - 1) {
 929                         errmsg = "filename too long";
 930                         return  NULL;
 931                 }
 932         }
 933 #ifndef BACKWARDS
 934         else if (*old_filename == '\0') {
 935                 errmsg = "no current filename";
 936                 return  NULL;
 937         }
 938 #endif
 939         REALLOC(file, filesz, PATH_MAX, NULL);
 940         for (n = 0; *ibufp != '\n';)
 941                 file[n++] = *ibufp++;
 942         file[n] = '\0';
 943         return is_legal_filename(file) ? file : NULL;
 944 }
 945
 946
 947 /* get_shell_command: read a shell command from stdin; return substitution
 948    status */
 949 int
 950 get_shell_command(void)
 951 {
 952         static char *buf = NULL;
 953         static int n = 0;
 954
 955         char *s;                        /* substitution char pointer */
 956         int i = 0;
 957         int j = 0;
 958
 959         if (red) {
 960                 errmsg = "shell access restricted";
 961                 return ERR;
 962         } else if ((s = ibufp = get_extended_line(&j, 1)) == NULL)
 963                 return ERR;
 964         REALLOC(buf, n, j + 1, ERR);
 965         buf[i++] = '!';                 /* prefix command w/ bang */
 966         while (*ibufp != '\n')
 967                 switch (*ibufp) {
 968                 default:
 969                         REALLOC(buf, n, i + 2, ERR);
 970                         buf[i++] = *ibufp;
 971                         if (*ibufp++ == '\\')
 972                                 buf[i++] = *ibufp++;
 973                         break;
 974                 case '!':
 975                         if (s != ibufp) {
 976                                 REALLOC(buf, n, i + 1, ERR);
 977                                 buf[i++] = *ibufp++;
 978                         }
 979 #ifdef BACKWARDS
 980                         else if (shcmd == NULL || *(shcmd + 1) == '\0')
 981 #else
 982                         else if (shcmd == NULL)
 983 #endif
 984                         {
 985                                 errmsg = "no previous command";
 986                                 return ERR;
 987                         } else {
 988                                 REALLOC(buf, n, i + shcmdi, ERR);
 989                                 for (s = shcmd + 1; s < shcmd + shcmdi;)
 990                                         buf[i++] = *s++;
 991                                 s = ibufp++;
 992                         }
 993                         break;
 994                 case '%':
 995                         if (*old_filename  == '\0') {
 996                                 errmsg = "no current filename";
 997                                 return ERR;
 998                         }
 999                         j = strlen(s = strip_escapes(old_filename));
1000                         REALLOC(buf, n, i + j, ERR);
1001                         while (j--)
1002                                 buf[i++] = *s++;
1003                         s = ibufp++;
1004                         break;
1005                 }
1006         REALLOC(shcmd, shcmdsz, i + 1, ERR);
1007         memcpy(shcmd, buf, i);
1008         shcmd[shcmdi = i] = '\0';
1009         return *s == '!' || *s == '%';
1010 }
1011
1012
1013 /* append_lines: insert text from stdin to after line n; stop when either a
1014    single period is read or EOF; return status */
1015 int
1016 append_lines(long n)
1017 {
1018         int l;
1019         const char *lp = ibuf;
1020         const char *eot;
1021         undo_t *up = NULL;
1022
1023         for (current_addr = n;;) {
1024                 if (!isglobal) {
1025                         if ((l = get_tty_line()) < 0)
1026                                 return ERR;
1027                         else if (l == 0 || ibuf[l - 1] != '\n') {
1028                                 clearerr(stdin);
1029                                 return  l ? EOF : 0;
1030                         }
1031                         lp = ibuf;
1032                 } else if (*(lp = ibufp) == '\0')
1033                         return 0;
1034                 else {
1035                         while (*ibufp++ != '\n')
1036                                 ;
1037                         l = ibufp - lp;
1038                 }
1039                 if (l == 2 && lp[0] == '.' && lp[1] == '\n') {
1040                         return 0;
1041                 }
1042                 eot = lp + l;
1043                 SPL1();
1044                 do {
1045                         if ((lp = put_sbuf_line(lp)) == NULL) {
1046                                 SPL0();
1047                                 return ERR;
1048                         } else if (up)
1049                                 up->t = get_addressed_line_node(current_addr);
1050                         else if ((up = push_undo_stack(UADD, current_addr,
1051                             current_addr)) == NULL) {
1052                                 SPL0();
1053                                 return ERR;
1054                         }
1055                 } while (lp != eot);
1056                 modified = 1;
1057                 SPL0();
1058         }
1059         /* NOTREACHED */
1060 }
1061
1062
1063 /* join_lines: replace a range of lines with the joined text of those lines */
1064 int
1065 join_lines(long from, long to)
1066 {
1067         static char *buf = NULL;
1068         static int n;
1069
1070         char *s;
1071         int size = 0;
1072         line_t *bp, *ep;
1073
1074         ep = get_addressed_line_node(INC_MOD(to, addr_last));
1075         bp = get_addressed_line_node(from);
1076         for (; bp != ep; bp = bp->q_forw) {
1077                 if ((s = get_sbuf_line(bp)) == NULL)
1078                         return ERR;
1079                 REALLOC(buf, n, size + bp->len, ERR);
1080                 memcpy(buf + size, s, bp->len);
1081                 size += bp->len;
1082         }
1083         REALLOC(buf, n, size + 2, ERR);
1084         memcpy(buf + size, "\n", 2);
1085         if (delete_lines(from, to) < 0)
1086                 return ERR;
1087         current_addr = from - 1;
1088         SPL1();
1089         if (put_sbuf_line(buf) == NULL ||
1090             push_undo_stack(UADD, current_addr, current_addr) == NULL) {
1091                 SPL0();
1092                 return ERR;
1093         }
1094         modified = 1;
1095         SPL0();
1096         return 0;
1097 }
1098
1099
1100 /* move_lines: move a range of lines */
1101 int
1102 move_lines(long addr)
1103 {
1104         line_t *b1, *a1, *b2, *a2;
1105         long n = INC_MOD(second_addr, addr_last);
1106         long p = first_addr - 1;
1107         int done = (addr == first_addr - 1 || addr == second_addr);
1108
1109         SPL1();
1110         if (done) {
1111                 a2 = get_addressed_line_node(n);
1112                 b2 = get_addressed_line_node(p);
1113                 current_addr = second_addr;
1114         } else if (push_undo_stack(UMOV, p, n) == NULL ||
1115             push_undo_stack(UMOV, addr, INC_MOD(addr, addr_last)) == NULL) {
1116                 SPL0();
1117                 return ERR;
1118         } else {
1119                 a1 = get_addressed_line_node(n);
1120                 if (addr < first_addr) {
1121                         b1 = get_addressed_line_node(p);
1122                         b2 = get_addressed_line_node(addr);
1123                                         /* this get_addressed_line_node last! */
1124                 } else {
1125                         b2 = get_addressed_line_node(addr);
1126                         b1 = get_addressed_line_node(p);
1127                                         /* this get_addressed_line_node last! */
1128                 }
1129                 a2 = b2->q_forw;
1130                 REQUE(b2, b1->q_forw);
1131                 REQUE(a1->q_back, a2);
1132                 REQUE(b1, a1);
1133                 current_addr = addr + ((addr < first_addr) ?
1134                     second_addr - first_addr + 1 : 0);
1135         }
1136         if (isglobal)
1137                 unset_active_nodes(b2->q_forw, a2);
1138         modified = 1;
1139         SPL0();
1140         return 0;
1141 }
1142
1143
1144 /* copy_lines: copy a range of lines; return status */
1145 int
1146 copy_lines(long addr)
1147 {
1148         line_t *lp, *np = get_addressed_line_node(first_addr);
1149         undo_t *up = NULL;
1150         long n = second_addr - first_addr + 1;
1151         long m = 0;
1152
1153         current_addr = addr;
1154         if (first_addr <= addr && addr < second_addr) {
1155                 n =  addr - first_addr + 1;
1156                 m = second_addr - addr;
1157         }
1158         for (; n > 0; n=m, m=0, np = get_addressed_line_node(current_addr + 1))
1159                 for (; n-- > 0; np = np->q_forw) {
1160                         SPL1();
1161                         if ((lp = dup_line_node(np)) == NULL) {
1162                                 SPL0();
1163                                 return ERR;
1164                         }
1165                         add_line_node(lp);
1166                         if (up)
1167                                 up->t = lp;
1168                         else if ((up = push_undo_stack(UADD, current_addr,
1169                             current_addr)) == NULL) {
1170                                 SPL0();
1171                                 return ERR;
1172                         }
1173                         modified = 1;
1174                         SPL0();
1175                 }
1176         return 0;
1177 }
1178
1179
1180 /* delete_lines: delete a range of lines */
1181 int
1182 delete_lines(long from, long to)
1183 {
1184         line_t *n, *p;
1185
1186         SPL1();
1187         if (push_undo_stack(UDEL, from, to) == NULL) {
1188                 SPL0();
1189                 return ERR;
1190         }
1191         n = get_addressed_line_node(INC_MOD(to, addr_last));
1192         p = get_addressed_line_node(from - 1);
1193                                         /* this get_addressed_line_node last! */
1194         if (isglobal)
1195                 unset_active_nodes(p->q_forw, n);
1196         REQUE(p, n);
1197         addr_last -= to - from + 1;
1198         current_addr = from - 1;
1199         modified = 1;
1200         SPL0();
1201         return 0;
1202 }
1203
1204
1205 /* display_lines: print a range of lines to stdout */
1206 int
1207 display_lines(long from, long to, int gflag)
1208 {
1209         line_t *bp;
1210         line_t *ep;
1211         char *s;
1212
1213         if (!from) {
1214                 errmsg = "invalid address";
1215                 return ERR;
1216         }
1217         ep = get_addressed_line_node(INC_MOD(to, addr_last));
1218         bp = get_addressed_line_node(from);
1219         for (; bp != ep; bp = bp->q_forw) {
1220                 if ((s = get_sbuf_line(bp)) == NULL)
1221                         return ERR;
1222                 if (put_tty_line(s, bp->len, current_addr = from++, gflag) < 0)
1223                         return ERR;
1224         }
1225         return 0;
1226 }
1227
1228
1229 #define MAXMARK 26                      /* max number of marks */
1230
1231 static line_t *mark[MAXMARK];           /* line markers */
1232 static int markno;                      /* line marker count */
1233
1234 /* mark_line_node: set a line node mark */
1235 int
1236 mark_line_node(line_t *lp, int n)
1237 {
1238         if (!islower((unsigned char)n)) {
1239                 errmsg = "invalid mark character";
1240                 return ERR;
1241         } else if (mark[n - 'a'] == NULL)
1242                 markno++;
1243         mark[n - 'a'] = lp;
1244         return 0;
1245 }
1246
1247
1248 /* get_marked_node_addr: return address of a marked line */
1249 long
1250 get_marked_node_addr(int n)
1251 {
1252         if (!islower((unsigned char)n)) {
1253                 errmsg = "invalid mark character";
1254                 return ERR;
1255         }
1256         return get_line_node_addr(mark[n - 'a']);
1257 }
1258
1259
1260 /* unmark_line_node: clear line node mark */
1261 void
1262 unmark_line_node(line_t *lp)
1263 {
1264         int i;
1265
1266         for (i = 0; markno && i < MAXMARK; i++)
1267                 if (mark[i] == lp) {
1268                         mark[i] = NULL;
1269                         markno--;
1270                 }
1271 }
1272
1273
1274 /* dup_line_node: return a pointer to a copy of a line node */
1275 line_t *
1276 dup_line_node(line_t *lp)
1277 {
1278         line_t *np;
1279
1280         if ((np = (line_t *) malloc(sizeof(line_t))) == NULL) {
1281                 fprintf(stderr, "%s\n", strerror(errno));
1282                 errmsg = "out of memory";
1283                 return NULL;
1284         }
1285         np->seek = lp->seek;
1286         np->len = lp->len;
1287         return np;
1288 }
1289
1290
1291 /* has_trailing_escape:  return the parity of escapes preceding a character
1292    in a string */
1293 int
1294 has_trailing_escape(char *s, char *t)
1295 {
1296     return (s == t || *(t - 1) != '\\') ? 0 : !has_trailing_escape(s, t - 1);
1297 }
1298
1299
1300 /* strip_escapes: return copy of escaped string of at most length PATH_MAX */
1301 char *
1302 strip_escapes(char *s)
1303 {
1304         static char *file = NULL;
1305         static int filesz = 0;
1306
1307         int i = 0;
1308
1309         REALLOC(file, filesz, PATH_MAX, NULL);
1310         while (i < filesz - 1   /* Worry about a possible trailing escape */
1311                && (file[i++] = (*s == '\\') ? *++s : *s))
1312                 s++;
1313         return file;
1314 }
1315
1316
1317 void
1318 signal_hup(int signo)
1319 {
1320         if (mutex)
1321                 sigflags |= (1 << (signo - 1));
1322         else
1323                 handle_hup(signo);
1324 }
1325
1326
1327 void
1328 signal_int(int signo)
1329 {
1330         if (mutex)
1331                 sigflags |= (1 << (signo - 1));
1332         else
1333                 handle_int(signo);
1334 }
1335
1336
1337 void
1338 handle_hup(int signo)
1339 {
1340         char *hup = NULL;               /* hup filename */
1341         char *s;
1342         char ed_hup[] = "ed.hup";
1343         int n;
1344
1345         if (!sigactive)
1346                 quit(1);
1347         sigflags &= ~(1 << (signo - 1));
1348         if (addr_last && write_file(ed_hup, "w", 1, addr_last) < 0 &&
1349             (s = getenv("HOME")) != NULL &&
1350             (n = strlen(s)) + 8 <= PATH_MAX &&  /* "ed.hup" + '/' */
1351             (hup = (char *) malloc(n + 10)) != NULL) {
1352                 strcpy(hup, s);
1353                 if (hup[n - 1] != '/')
1354                         hup[n] = '/', hup[n+1] = '\0';
1355                 strcat(hup, "ed.hup");
1356                 write_file(hup, "w", 1, addr_last);
1357         }
1358         quit(2);
1359 }
1360
1361
1362 void
1363 handle_int(int signo)
1364 {
1365         if (!sigactive)
1366                 quit(1);
1367         sigflags &= ~(1 << (signo - 1));
1368         siglongjmp(env, -1);
1369 }
1370
1371
1372 int cols = 72;                          /* wrap column */
1373
1374 void
1375 handle_winch(int signo)
1376 {
1377         int save_errno = errno;
1378
1379         struct winsize ws;              /* window size structure */
1380
1381         sigflags &= ~(1 << (signo - 1));
1382         if (ioctl(0, TIOCGWINSZ, (char *) &ws) >= 0) {
1383                 if (ws.ws_row > 2) rows = ws.ws_row - 2;
1384                 if (ws.ws_col > 8) cols = ws.ws_col - 8;
1385         }
1386         errno = save_errno;
1387 }
1388
1389
1390 /* is_legal_filename: return a legal filename */
1391 int
1392 is_legal_filename(char *s)
1393 {
1394         if (red && (*s == '!' || !strcmp(s, "..") || strchr(s, '/'))) {
1395                 errmsg = "shell access restricted";
1396                 return 0;
1397         }
1398         return 1;
1399 }