external/bsd/nvi/dist/ex/ex_subst.c

   1 /*      $NetBSD: ex_subst.c,v 1.3 2013/11/25 22:43:46 christos Exp $ */
   2 /*-
   3  * Copyright (c) 1992, 1993, 1994
   4  *      The Regents of the University of California.  All rights reserved.
   5  * Copyright (c) 1992, 1993, 1994, 1995, 1996
   6  *      Keith Bostic.  All rights reserved.
   7  *
   8  * See the LICENSE file for redistribution information.
   9  */
  10
  11 #include "config.h"
  12
  13 #ifndef lint
  14 static const char sccsid[] = "Id: ex_subst.c,v 10.50 2002/02/09 21:18:23 skimo Exp  (Berkeley) Date: 2002/02/09 21:18:23 ";
  15 #endif /* not lint */
  16
  17 #include <sys/types.h>
  18 #include <sys/queue.h>
  19 #include <sys/time.h>
  20
  21 #include <bitstring.h>
  22 #include <ctype.h>
  23 #include <errno.h>
  24 #include <limits.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <unistd.h>
  29
  30 #include "../common/common.h"
  31 #include "../vi/vi.h"
  32
  33 #define SUB_FIRST       0x01            /* The 'r' flag isn't reasonable. */
  34 #define SUB_MUSTSETR    0x02            /* The 'r' flag is required. */
  35
  36 static int re_conv __P((SCR *, CHAR_T **, size_t *, int *));
  37 static int re_cscope_conv __P((SCR *, CHAR_T **, size_t *, int *));
  38 static int re_sub __P((SCR *,
  39                 CHAR_T *, CHAR_T **, size_t *, size_t *, regmatch_t [10]));
  40 static int re_tag_conv __P((SCR *, CHAR_T **, size_t *, int *));
  41 static int s __P((SCR *, EXCMD *, CHAR_T *, regex_t *, u_int));
  42
  43 /*
  44  * ex_s --
  45  *      [line [,line]] s[ubstitute] [[/;]pat[/;]/repl[/;] [cgr] [count] [#lp]]
  46  *
  47  *      Substitute on lines matching a pattern.
  48  *
  49  * PUBLIC: int ex_s __P((SCR *, EXCMD *));
  50  */
  51 int
  52 ex_s(SCR *sp, EXCMD *cmdp)
  53 {
  54         regex_t *re;
  55         size_t blen, len;
  56         u_int flags;
  57         ARG_CHAR_T delim;
  58         CHAR_T *bp, *p, *ptrn, *rep, *t;
  59
  60         /*
  61          * Skip leading white space.
  62          *
  63          * !!!
  64          * Historic vi allowed any non-alphanumeric to serve as the
  65          * substitution command delimiter.
  66          *
  67          * !!!
  68          * If the arguments are empty, it's the same as &, i.e. we
  69          * repeat the last substitution.
  70          */
  71         if (cmdp->argc == 0)
  72                 goto subagain;
  73         for (p = cmdp->argv[0]->bp,
  74             len = cmdp->argv[0]->len; len > 0; --len, ++p) {
  75                 if (!ISBLANK((UCHAR_T)*p))
  76                         break;
  77         }
  78         if (len == 0)
  79 subagain:       return (ex_subagain(sp, cmdp));
  80
  81         delim = (UCHAR_T)*p++;
  82         if (ISALNUM(delim) || delim == '\\')
  83                 return (s(sp, cmdp, p, &sp->subre_c, SUB_MUSTSETR));
  84
  85         /*
  86          * !!!
  87          * The full-blown substitute command reset the remembered
  88          * state of the 'c' and 'g' suffices.
  89          */
  90         sp->c_suffix = sp->g_suffix = 0;
  91
  92         /*
  93          * Get the pattern string, toss escaping characters.
  94          *
  95          * !!!
  96          * Historic vi accepted any of the following forms:
  97          *
  98          *      :s/abc/def/             change "abc" to "def"
  99          *      :s/abc/def              change "abc" to "def"
 100          *      :s/abc/                 delete "abc"
 101          *      :s/abc                  delete "abc"
 102          *
 103          * QUOTING NOTE:
 104          *
 105          * Only toss an escaping character if it escapes a delimiter.
 106          * This means that "s/A/\\\\f" replaces "A" with "\\f".  It
 107          * would be nice to be more regular, i.e. for each layer of
 108          * escaping a single escaping character is removed, but that's
 109          * not how the historic vi worked.
 110          */
 111         for (ptrn = t = p;;) {
 112                 if (p[0] == '\0' || p[0] == delim) {
 113                         if (p[0] == delim)
 114                                 ++p;
 115                         /*
 116                          * !!!
 117                          * Nul terminate the pattern string -- it's passed
 118                          * to regcomp which doesn't understand anything else.
 119                          */
 120                         *t = '\0';
 121                         break;
 122                 }
 123                 if (p[0] == '\\') {
 124                         if (p[1] == delim)
 125                                 ++p;
 126                         else if (p[1] == '\\')
 127                                 *t++ = *p++;
 128                 }
 129                 *t++ = *p++;
 130         }
 131
 132         /*
 133          * If the pattern string is empty, use the last RE (not just the
 134          * last substitution RE).
 135          */
 136         if (*ptrn == '\0') {
 137                 if (sp->re == NULL) {
 138                         ex_emsg(sp, NULL, EXM_NOPREVRE);
 139                         return (1);
 140                 }
 141
 142                 /* Re-compile the RE if necessary. */
 143                 if (!F_ISSET(sp, SC_RE_SEARCH) &&
 144                     re_compile(sp, sp->re, sp->re_len,
 145                     NULL, NULL, &sp->re_c, SEARCH_CSEARCH | SEARCH_MSG))
 146                         return (1);
 147                 flags = 0;
 148         } else {
 149                 /*
 150                  * !!!
 151                  * Compile the RE.  Historic practice is that substitutes set
 152                  * the search direction as well as both substitute and search
 153                  * RE's.  We compile the RE twice, as we don't want to bother
 154                  * ref counting the pattern string and (opaque) structure.
 155                  */
 156                 if (re_compile(sp, ptrn, t - ptrn, &sp->re,
 157                     &sp->re_len, &sp->re_c, SEARCH_CSEARCH | SEARCH_MSG))
 158                         return (1);
 159                 if (re_compile(sp, ptrn, t - ptrn, &sp->subre,
 160                     &sp->subre_len, &sp->subre_c, SEARCH_CSUBST | SEARCH_MSG))
 161                         return (1);
 162
 163                 flags = SUB_FIRST;
 164                 sp->searchdir = FORWARD;
 165         }
 166         re = &sp->re_c;
 167
 168         /*
 169          * Get the replacement string.
 170          *
 171          * The special character & (\& if O_MAGIC not set) matches the
 172          * entire RE.  No handling of & is required here, it's done by
 173          * re_sub().
 174          *
 175          * The special character ~ (\~ if O_MAGIC not set) inserts the
 176          * previous replacement string into this replacement string.
 177          * Count ~'s to figure out how much space we need.  We could
 178          * special case nonexistent last patterns or whether or not
 179          * O_MAGIC is set, but it's probably not worth the effort.
 180          *
 181          * QUOTING NOTE:
 182          *
 183          * Only toss an escaping character if it escapes a delimiter or
 184          * if O_MAGIC is set and it escapes a tilde.
 185          *
 186          * !!!
 187          * If the entire replacement pattern is "%", then use the last
 188          * replacement pattern.  This semantic was added to vi in System
 189          * V and then percolated elsewhere, presumably around the time
 190          * that it was added to their version of ed(1).
 191          */
 192         if (p[0] == L('\0') || p[0] == delim) {
 193                 if (p[0] == delim)
 194                         ++p;
 195                 if (sp->repl != NULL)
 196                         free(sp->repl);
 197                 sp->repl = NULL;
 198                 sp->repl_len = 0;
 199         } else if (p[0] == L('%') && (p[1] == L('\0') || p[1] == delim))
 200                 p += p[1] == delim ? 2 : 1;
 201         else {
 202                 for (rep = p, len = 0;
 203                     p[0] != L('\0') && p[0] != delim; ++p, ++len)
 204                         if (p[0] == L('~'))
 205                                 len += sp->repl_len;
 206                 GET_SPACE_RETW(sp, bp, blen, len);
 207                 for (t = bp, len = 0, p = rep;;) {
 208                         if (p[0] == L('\0') || p[0] == delim) {
 209                                 if (p[0] == delim)
 210                                         ++p;
 211                                 break;
 212                         }
 213                         if (p[0] == L('\\')) {
 214                                 if (p[1] == delim)
 215                                         ++p;
 216                                 else if (p[1] == L('\\')) {
 217                                         *t++ = *p++;
 218                                         ++len;
 219                                 } else if (p[1] == L('~')) {
 220                                         ++p;
 221                                         if (!O_ISSET(sp, O_MAGIC))
 222                                                 goto tilde;
 223                                 }
 224                         } else if (p[0] == L('~') && O_ISSET(sp, O_MAGIC)) {
 225 tilde:                          ++p;
 226                                 MEMCPYW(t, sp->repl, sp->repl_len);
 227                                 t += sp->repl_len;
 228                                 len += sp->repl_len;
 229                                 continue;
 230                         }
 231                         *t++ = *p++;
 232                         ++len;
 233                 }
 234                 if ((sp->repl_len = len) != 0) {
 235                         if (sp->repl != NULL)
 236                                 free(sp->repl);
 237                         if ((sp->repl = malloc(len * sizeof(CHAR_T))) == NULL) {
 238                                 msgq(sp, M_SYSERR, NULL);
 239                                 FREE_SPACEW(sp, bp, blen);
 240                                 return (1);
 241                         }
 242                         MEMCPYW(sp->repl, bp, len);
 243                 }
 244                 FREE_SPACEW(sp, bp, blen);
 245         }
 246         return (s(sp, cmdp, p, re, flags));
 247 }
 248
 249 /*
 250  * ex_subagain --
 251  *      [line [,line]] & [cgr] [count] [#lp]]
 252  *
 253  *      Substitute using the last substitute RE and replacement pattern.
 254  *
 255  * PUBLIC: int ex_subagain __P((SCR *, EXCMD *));
 256  */
 257 int
 258 ex_subagain(SCR *sp, EXCMD *cmdp)
 259 {
 260         if (sp->subre == NULL) {
 261                 ex_emsg(sp, NULL, EXM_NOPREVRE);
 262                 return (1);
 263         }
 264         if (!F_ISSET(sp, SC_RE_SUBST) &&
 265             re_compile(sp, sp->subre, sp->subre_len,
 266             NULL, NULL, &sp->subre_c, SEARCH_CSUBST | SEARCH_MSG))
 267                 return (1);
 268         return (s(sp,
 269             cmdp, cmdp->argc ? cmdp->argv[0]->bp : NULL, &sp->subre_c, 0));
 270 }
 271
 272 /*
 273  * ex_subtilde --
 274  *      [line [,line]] ~ [cgr] [count] [#lp]]
 275  *
 276  *      Substitute using the last RE and last substitute replacement pattern.
 277  *
 278  * PUBLIC: int ex_subtilde __P((SCR *, EXCMD *));
 279  */
 280 int
 281 ex_subtilde(SCR *sp, EXCMD *cmdp)
 282 {
 283         if (sp->re == NULL) {
 284                 ex_emsg(sp, NULL, EXM_NOPREVRE);
 285                 return (1);
 286         }
 287         if (!F_ISSET(sp, SC_RE_SEARCH) && re_compile(sp, sp->re,
 288             sp->re_len, NULL, NULL, &sp->re_c, SEARCH_CSEARCH | SEARCH_MSG))
 289                 return (1);
 290         return (s(sp,
 291             cmdp, cmdp->argc ? cmdp->argv[0]->bp : NULL, &sp->re_c, 0));
 292 }
 293
 294 /*
 295  * s --
 296  * Do the substitution.  This stuff is *really* tricky.  There are lots of
 297  * special cases, and general nastiness.  Don't mess with it unless you're
 298  * pretty confident.
 299  *
 300  * The nasty part of the substitution is what happens when the replacement
 301  * string contains newlines.  It's a bit tricky -- consider the information
 302  * that has to be retained for "s/f\(o\)o/^M\1^M\1/".  The solution here is
 303  * to build a set of newline offsets which we use to break the line up later,
 304  * when the replacement is done.  Don't change it unless you're *damned*
 305  * confident.
 306  */
 307 #define NEEDNEWLINE(sp) {                                               \
 308         if (sp->newl_len == sp->newl_cnt) {                             \
 309                 sp->newl_len += 25;                                     \
 310                 REALLOC(sp, sp->newl, size_t *,                         \
 311                     sp->newl_len * sizeof(size_t));                     \
 312                 if (sp->newl == NULL) {                                 \
 313                         sp->newl_len = 0;                               \
 314                         return (1);                                     \
 315                 }                                                       \
 316         }                                                               \
 317 }
 318
 319 #define BUILD(sp, l, len) {                                             \
 320         if (lbclen + (len) > lblen) {                                   \
 321                 lblen += MAX(lbclen + (len), 256);                      \
 322                 REALLOC(sp, lb, CHAR_T *, lblen * sizeof(CHAR_T));      \
 323                 if (lb == NULL) {                                       \
 324                         lbclen = 0;                                     \
 325                         return (1);                                     \
 326                 }                                                       \
 327         }                                                               \
 328         MEMCPYW(lb + lbclen, l, len);                                   \
 329         lbclen += len;                                                  \
 330 }
 331
 332 #define NEEDSP(sp, len, pnt) {                                          \
 333         if (lbclen + (len) > lblen) {                                   \
 334                 lblen += MAX(lbclen + (len), 256);                      \
 335                 REALLOC(sp, lb, CHAR_T *, lblen * sizeof(CHAR_T));      \
 336                 if (lb == NULL) {                                       \
 337                         lbclen = 0;                                     \
 338                         return (1);                                     \
 339                 }                                                       \
 340                 pnt = lb + lbclen;                                      \
 341         }                                                               \
 342 }
 343
 344 static int
 345 s(SCR *sp, EXCMD *cmdp, CHAR_T *st, regex_t *re, u_int flags)
 346 {
 347         EVENT ev;
 348         MARK from, to;
 349         TEXTH tiq;
 350         db_recno_t elno, lno, slno;
 351         u_long ul;
 352         regmatch_t match[10];
 353         size_t blen, cnt, last, lbclen, lblen, len, llen;
 354         size_t offset, saved_offset, scno;
 355         int lflag, nflag, pflag, rflag;
 356         int didsub, do_eol_match, eflags, empty_ok, eval;
 357         int linechanged, matched, quit, rval;
 358         CHAR_T *lb, *bp;
 359         enum nresult nret;
 360
 361         NEEDFILE(sp, cmdp);
 362
 363         slno = sp->lno;
 364         scno = sp->cno;
 365
 366         /*
 367          * !!!
 368          * Historically, the 'g' and 'c' suffices were always toggled as flags,
 369          * so ":s/A/B/" was the same as ":s/A/B/ccgg".  If O_EDCOMPATIBLE was
 370          * not set, they were initialized to 0 for all substitute commands.  If
 371          * O_EDCOMPATIBLE was set, they were initialized to 0 only if the user
 372          * specified substitute/replacement patterns (see ex_s()).
 373          */
 374         if (!O_ISSET(sp, O_EDCOMPATIBLE))
 375                 sp->c_suffix = sp->g_suffix = 0;
 376
 377         /*
 378          * Historic vi permitted the '#', 'l' and 'p' options in vi mode, but
 379          * it only displayed the last change.  I'd disallow them, but they are
 380          * useful in combination with the [v]global commands.  In the current
 381          * model the problem is combining them with the 'c' flag -- the screen
 382          * would have to flip back and forth between the confirm screen and the
 383          * ex print screen, which would be pretty awful.  We do display all
 384          * changes, though, for what that's worth.
 385          *
 386          * !!!
 387          * Historic vi was fairly strict about the order of "options", the
 388          * count, and "flags".  I'm somewhat fuzzy on the difference between
 389          * options and flags, anyway, so this is a simpler approach, and we
 390          * just take it them in whatever order the user gives them.  (The ex
 391          * usage statement doesn't reflect this.)
 392          */
 393         lflag = nflag = pflag = rflag = 0;
 394         if (st == NULL)
 395                 goto noargs;
 396         for (lno = OOBLNO; *st != '\0'; ++st)
 397                 switch (*st) {
 398                 case ' ':
 399                 case '\t':
 400                         continue;
 401                 case '+':
 402                         ++cmdp->flagoff;
 403                         break;
 404                 case '-':
 405                         --cmdp->flagoff;
 406                         break;
 407                 case '0': case '1': case '2': case '3': case '4':
 408                 case '5': case '6': case '7': case '8': case '9':
 409                         if (lno != OOBLNO)
 410                                 goto usage;
 411                         errno = 0;
 412                         nret = nget_uslong(sp, &ul, st, &st, 10);
 413                         lno = ul;
 414                         if (*st == '\0')                /* Loop increment correction. */
 415                                 --st;
 416                         if (nret != NUM_OK) {
 417                                 if (nret == NUM_OVER)
 418                                         msgq(sp, M_ERR, "153|Count overflow");
 419                                 else if (nret == NUM_UNDER)
 420                                         msgq(sp, M_ERR, "154|Count underflow");
 421                                 else
 422                                         msgq(sp, M_SYSERR, NULL);
 423                                 return (1);
 424                         }
 425                         /*
 426                          * In historic vi, the count was inclusive from the
 427                          * second address.
 428                          */
 429                         cmdp->addr1.lno = cmdp->addr2.lno;
 430                         cmdp->addr2.lno += lno - 1;
 431                         if (!db_exist(sp, cmdp->addr2.lno) &&
 432                             db_last(sp, &cmdp->addr2.lno))
 433                                 return (1);
 434                         break;
 435                 case '#':
 436                         nflag = 1;
 437                         break;
 438                 case 'c':
 439                         sp->c_suffix = !sp->c_suffix;
 440
 441                         /* Ex text structure initialization. */
 442                         if (F_ISSET(sp, SC_EX)) {
 443                                 memset(&tiq, 0, sizeof(TEXTH));
 444                                 TAILQ_INIT(&tiq);
 445                         }
 446                         break;
 447                 case 'g':
 448                         sp->g_suffix = !sp->g_suffix;
 449                         break;
 450                 case 'l':
 451                         lflag = 1;
 452                         break;
 453                 case 'p':
 454                         pflag = 1;
 455                         break;
 456                 case 'r':
 457                         if (LF_ISSET(SUB_FIRST)) {
 458                                 msgq(sp, M_ERR,
 459                     "155|Regular expression specified; r flag meaningless");
 460                                 return (1);
 461                         }
 462                         if (!F_ISSET(sp, SC_RE_SEARCH)) {
 463                                 ex_emsg(sp, NULL, EXM_NOPREVRE);
 464                                 return (1);
 465                         }
 466                         rflag = 1;
 467                         re = &sp->re_c;
 468                         break;
 469                 default:
 470                         goto usage;
 471                 }
 472
 473         if (*st != '\0' || (!rflag && LF_ISSET(SUB_MUSTSETR))) {
 474 usage:          ex_emsg(sp, cmdp->cmd->usage, EXM_USAGE);
 475                 return (1);
 476         }
 477
 478 noargs: if (F_ISSET(sp, SC_VI) && sp->c_suffix && (lflag || nflag || pflag)) {
 479                 msgq(sp, M_ERR,
 480 "156|The #, l and p flags may not be combined with the c flag in vi mode");
 481                 return (1);
 482         }
 483
 484         /*
 485          * bp:          if interactive, line cache
 486          * blen:        if interactive, line cache length
 487          * lb:          build buffer pointer.
 488          * lbclen:      current length of built buffer.
 489          * lblen;       length of build buffer.
 490          */
 491         bp = lb = NULL;
 492         blen = lbclen = lblen = 0;
 493
 494         /* For each line... */
 495         lno = cmdp->addr1.lno == 0 ? 1 : cmdp->addr1.lno;
 496         for (matched = quit = 0,
 497             elno = cmdp->addr2.lno; !quit && lno <= elno; ++lno) {
 498
 499                 /* Someone's unhappy, time to stop. */
 500                 if (INTERRUPTED(sp))
 501                         break;
 502
 503                 /* Get the line. */
 504                 if (db_get(sp, lno, DBG_FATAL, &st, &llen))
 505                         goto err;
 506
 507                 /*
 508                  * Make a local copy if doing confirmation -- when calling
 509                  * the confirm routine we're likely to lose the cached copy.
 510                  */
 511                 if (sp->c_suffix) {
 512                         if (bp == NULL) {
 513                                 GET_SPACE_RETW(sp, bp, blen, llen);
 514                         } else
 515                                 ADD_SPACE_RETW(sp, bp, blen, llen);
 516                         MEMCPYW(bp, st, llen);
 517                         st = bp;
 518                 }
 519
 520                 /* Start searching from the beginning. */
 521                 offset = 0;
 522                 len = llen;
 523
 524                 /* Reset the build buffer offset. */
 525                 lbclen = 0;
 526
 527                 /* Reset empty match flag. */
 528                 empty_ok = 1;
 529
 530                 /*
 531                  * We don't want to have to do a setline if the line didn't
 532                  * change -- keep track of whether or not this line changed.
 533                  * If doing confirmations, don't want to keep setting the
 534                  * line if change is refused -- keep track of substitutions.
 535                  */
 536                 didsub = linechanged = 0;
 537
 538                 /* New line, do an EOL match. */
 539                 do_eol_match = 1;
 540
 541                 /* It's not nul terminated, but we pretend it is. */
 542                 eflags = REG_STARTEND;
 543
 544                 /*
 545                  * The search area is from st + offset to the EOL.
 546                  *
 547                  * Generally, match[0].rm_so is the offset of the start
 548                  * of the match from the start of the search, and offset
 549                  * is the offset of the start of the last search.
 550                  */
 551 nextmatch:      match[0].rm_so = 0;
 552                 match[0].rm_eo = len;
 553
 554                 /* Get the next match. */
 555                 eval = regexec(re, st + offset, 10, match, eflags);
 556
 557                 /*
 558                  * There wasn't a match or if there was an error, deal with
 559                  * it.  If there was a previous match in this line, resolve
 560                  * the changes into the database.  Otherwise, just move on.
 561                  */
 562                 if (eval == REG_NOMATCH)
 563                         goto endmatch;
 564                 if (eval != 0) {
 565                         re_error(sp, eval, re);
 566                         goto err;
 567                 }
 568                 matched = 1;
 569
 570                 /* Only the first search can match an anchored expression. */
 571                 eflags |= REG_NOTBOL;
 572
 573                 /*
 574                  * !!!
 575                  * It's possible to match 0-length strings -- for example, the
 576                  * command s;a*;X;, when matched against the string "aabb" will
 577                  * result in "XbXbX", i.e. the matches are "aa", the space
 578                  * between the b's and the space between the b's and the end of
 579                  * the string.  There is a similar space between the beginning
 580                  * of the string and the a's.  The rule that we use (because vi
 581                  * historically used it) is that any 0-length match, occurring
 582                  * immediately after a match, is ignored.  Otherwise, the above
 583                  * example would have resulted in "XXbXbX".  Another example is
 584                  * incorrectly using " *" to replace groups of spaces with one
 585                  * space.
 586                  *
 587                  * The way we do this is that if we just had a successful match,
 588                  * the starting offset does not skip characters, and the match
 589                  * is empty, ignore the match and move forward.  If there's no
 590                  * more characters in the string, we were attempting to match
 591                  * after the last character, so quit.
 592                  */
 593                 if (!empty_ok && match[0].rm_so == 0 && match[0].rm_eo == 0) {
 594                         empty_ok = 1;
 595                         if (len == 0)
 596                                 goto endmatch;
 597                         BUILD(sp, st + offset, 1)
 598                         ++offset;
 599                         --len;
 600                         goto nextmatch;
 601                 }
 602
 603                 /* Confirm change. */
 604                 if (sp->c_suffix) {
 605                         /*
 606                          * Set the cursor position for confirmation.  Note,
 607                          * if we matched on a '$', the cursor may be past
 608                          * the end of line.
 609                          */
 610                         from.lno = to.lno = lno;
 611                         from.cno = match[0].rm_so + offset;
 612                         to.cno = match[0].rm_eo + offset;
 613                         /*
 614                          * Both ex and vi have to correct for a change before
 615                          * the first character in the line.
 616                          */
 617                         if (llen == 0)
 618                                 from.cno = to.cno = 0;
 619                         if (F_ISSET(sp, SC_VI)) {
 620                                 /*
 621                                  * Only vi has to correct for a change after
 622                                  * the last character in the line.
 623                                  *
 624                                  * XXX
 625                                  * It would be nice to change the vi code so
 626                                  * that we could display a cursor past EOL.
 627                                  */
 628                                 if (to.cno >= llen)
 629                                         to.cno = llen - 1;
 630                                 if (from.cno >= llen)
 631                                         from.cno = llen - 1;
 632
 633                                 sp->lno = from.lno;
 634                                 sp->cno = from.cno;
 635                                 if (vs_refresh(sp, 1))
 636                                         goto err;
 637
 638                                 vs_update(sp, msg_cat(sp,
 639                                     "169|Confirm change? [n]", NULL), NULL);
 640
 641                                 if (v_event_get(sp, &ev, 0, 0))
 642                                         goto err;
 643                                 switch (ev.e_event) {
 644                                 case E_CHARACTER:
 645                                         break;
 646                                 case E_EOF:
 647                                 case E_ERR:
 648                                 case E_INTERRUPT:
 649                                         goto lquit;
 650                                 default:
 651                                         v_event_err(sp, &ev);
 652                                         goto lquit;
 653                                 }
 654                         } else {
 655                                 if (ex_print(sp, cmdp, &from, &to, 0) ||
 656                                     ex_scprint(sp, &from, &to))
 657                                         goto lquit;
 658                                 if (ex_txt(sp, &tiq, 0, TXT_CR))
 659                                         goto err;
 660                                 ev.e_c = TAILQ_FIRST(&tiq)->lb[0];
 661                         }
 662
 663                         switch (ev.e_c) {
 664                         case CH_YES:
 665                                 break;
 666                         default:
 667                         case CH_NO:
 668                                 didsub = 0;
 669                                 BUILD(sp, st + offset, match[0].rm_eo);
 670                                 goto skip;
 671                         case CH_QUIT:
 672                                 /* Set the quit/interrupted flags. */
 673 lquit:                          quit = 1;
 674                                 F_SET(sp->gp, G_INTERRUPTED);
 675
 676                                 /*
 677                                  * Resolve any changes, then return to (and
 678                                  * exit from) the main loop.
 679                                  */
 680                                 goto endmatch;
 681                         }
 682                 }
 683
 684                 /*
 685                  * Set the cursor to the last position changed, converting
 686                  * from 1-based to 0-based.
 687                  */
 688                 sp->lno = lno;
 689                 sp->cno = match[0].rm_so;
 690
 691                 /* Copy the bytes before the match into the build buffer. */
 692                 BUILD(sp, st + offset, match[0].rm_so);
 693
 694                 /* Substitute the matching bytes. */
 695                 didsub = 1;
 696                 if (re_sub(sp, st + offset, &lb, &lbclen, &lblen, match))
 697                         goto err;
 698
 699                 /* Set the change flag so we know this line was modified. */
 700                 linechanged = 1;
 701
 702                 /* Move past the matched bytes. */
 703 skip:           offset += match[0].rm_eo;
 704                 len -= match[0].rm_eo;
 705
 706                 /* A match cannot be followed by an empty pattern. */
 707                 empty_ok = 0;
 708
 709                 /*
 710                  * If doing a global change with confirmation, we have to
 711                  * update the screen.  The basic idea is to store the line
 712                  * so the screen update routines can find it, and restart.
 713                  */
 714                 if (didsub && sp->c_suffix && sp->g_suffix) {
 715                         /*
 716                          * The new search offset will be the end of the
 717                          * modified line.
 718                          */
 719                         saved_offset = lbclen;
 720
 721                         /* Copy the rest of the line. */
 722                         if (len)
 723                                 BUILD(sp, st + offset, len)
 724
 725                         /* Set the new offset. */
 726                         offset = saved_offset;
 727
 728                         /* Store inserted lines, adjusting the build buffer. */
 729                         last = 0;
 730                         if (sp->newl_cnt) {
 731                                 for (cnt = 0;
 732                                     cnt < sp->newl_cnt; ++cnt, ++lno, ++elno) {
 733                                         if (db_insert(sp, lno,
 734                                             lb + last, sp->newl[cnt] - last))
 735                                                 goto err;
 736                                         last = sp->newl[cnt] + 1;
 737                                         ++sp->rptlines[L_ADDED];
 738                                 }
 739                                 lbclen -= last;
 740                                 offset -= last;
 741                                 sp->newl_cnt = 0;
 742                         }
 743
 744                         /* Store and retrieve the line. */
 745                         if (db_set(sp, lno, lb + last, lbclen))
 746                                 goto err;
 747                         if (db_get(sp, lno, DBG_FATAL, &st, &llen))
 748                                 goto err;
 749                         ADD_SPACE_RETW(sp, bp, blen, llen)
 750                         MEMCPYW(bp, st, llen);
 751                         st = bp;
 752                         len = llen - offset;
 753
 754                         /* Restart the build. */
 755                         lbclen = 0;
 756                         BUILD(sp, st, offset);
 757
 758                         /*
 759                          * If we haven't already done the after-the-string
 760                          * match, do one.  Set REG_NOTEOL so the '$' pattern
 761                          * only matches once.
 762                          */
 763                         if (!do_eol_match)
 764                                 goto endmatch;
 765                         if (offset == len) {
 766                                 do_eol_match = 0;
 767                                 eflags |= REG_NOTEOL;
 768                         }
 769                         goto nextmatch;
 770                 }
 771
 772                 /*
 773                  * If it's a global:
 774                  *
 775                  * If at the end of the string, do a test for the after
 776                  * the string match.  Set REG_NOTEOL so the '$' pattern
 777                  * only matches once.
 778                  */
 779                 if (sp->g_suffix && do_eol_match) {
 780                         if (len == 0) {
 781                                 do_eol_match = 0;
 782                                 eflags |= REG_NOTEOL;
 783                         }
 784                         goto nextmatch;
 785                 }
 786
 787 endmatch:       if (!linechanged)
 788                         continue;
 789
 790                 /* Copy any remaining bytes into the build buffer. */
 791                 if (len)
 792                         BUILD(sp, st + offset, len)
 793
 794                 /* Store inserted lines, adjusting the build buffer. */
 795                 last = 0;
 796                 if (sp->newl_cnt) {
 797                         for (cnt = 0;
 798                             cnt < sp->newl_cnt; ++cnt, ++lno, ++elno) {
 799                                 if (db_insert(sp,
 800                                     lno, lb + last, sp->newl[cnt] - last))
 801                                         goto err;
 802                                 last = sp->newl[cnt] + 1;
 803                                 ++sp->rptlines[L_ADDED];
 804                         }
 805                         lbclen -= last;
 806                         sp->newl_cnt = 0;
 807                 }
 808
 809                 /* Store the changed line. */
 810                 if (db_set(sp, lno, lb + last, lbclen))
 811                         goto err;
 812
 813                 /* Update changed line counter. */
 814                 if (sp->rptlchange != lno) {
 815                         sp->rptlchange = lno;
 816                         ++sp->rptlines[L_CHANGED];
 817                 }
 818
 819                 /*
 820                  * !!!
 821                  * Display as necessary.  Historic practice is to only
 822                  * display the last line of a line split into multiple
 823                  * lines.
 824                  */
 825                 if (lflag || nflag || pflag) {
 826                         from.lno = to.lno = lno;
 827                         from.cno = to.cno = 0;
 828                         if (lflag)
 829                                 (void)ex_print(sp, cmdp, &from, &to, E_C_LIST);
 830                         if (nflag)
 831                                 (void)ex_print(sp, cmdp, &from, &to, E_C_HASH);
 832                         if (pflag)
 833                                 (void)ex_print(sp, cmdp, &from, &to, E_C_PRINT);
 834                 }
 835         }
 836
 837         /*
 838          * !!!
 839          * Historically, vi attempted to leave the cursor at the same place if
 840          * the substitution was done at the current cursor position.  Otherwise
 841          * it moved it to the first non-blank of the last line changed.  There
 842          * were some problems: for example, :s/$/foo/ with the cursor on the
 843          * last character of the line left the cursor on the last character, or
 844          * the & command with multiple occurrences of the matching string in the
 845          * line usually left the cursor in a fairly random position.
 846          *
 847          * We try to do the same thing, with the exception that if the user is
 848          * doing substitution with confirmation, we move to the last line about
 849          * which the user was consulted, as opposed to the last line that they
 850          * actually changed.  This prevents a screen flash if the user doesn't
 851          * change many of the possible lines.
 852          */
 853         if (!sp->c_suffix && (sp->lno != slno || sp->cno != scno)) {
 854                 sp->cno = 0;
 855                 (void)nonblank(sp, sp->lno, &sp->cno);
 856         }
 857
 858         /*
 859          * If not in a global command, and nothing matched, say so.
 860          * Else, if none of the lines displayed, put something up.
 861          */
 862         rval = 0;
 863         if (!matched) {
 864                 if (!F_ISSET(sp, SC_EX_GLOBAL)) {
 865                         msgq(sp, M_ERR, "157|No match found");
 866                         goto err;
 867                 }
 868         } else if (!lflag && !nflag && !pflag)
 869                 F_SET(cmdp, E_AUTOPRINT);
 870
 871         if (0) {
 872 err:            rval = 1;
 873         }
 874
 875         if (bp != NULL)
 876                 FREE_SPACEW(sp, bp, blen);
 877         if (lb != NULL)
 878                 free(lb);
 879         return (rval);
 880 }
 881
 882 /*
 883  * re_compile --
 884  *      Compile the RE.
 885  *
 886  * PUBLIC: int re_compile __P((SCR *,
 887  * PUBLIC:     CHAR_T *, size_t, CHAR_T **, size_t *, regex_t *, u_int));
 888  */
 889 int
 890 re_compile(SCR *sp, CHAR_T *ptrn, size_t plen, CHAR_T **ptrnp, size_t *lenp, regex_t *rep, u_int flags)
 891 {
 892         size_t len;
 893         int reflags, replaced, rval;
 894         CHAR_T *p;
 895
 896         /* Set RE flags. */
 897         reflags = 0;
 898         if (LF_ISSET(SEARCH_EXTEND))
 899                 reflags |= REG_EXTENDED;
 900         if (LF_ISSET(SEARCH_IC))
 901                 reflags |= REG_ICASE;
 902         if (LF_ISSET(SEARCH_LITERAL))
 903                 reflags |= REG_NOSPEC;
 904         if (!LF_ISSET(SEARCH_NOOPT | SEARCH_CSCOPE | SEARCH_TAG)) {
 905                 if (O_ISSET(sp, O_EXTENDED))
 906                         reflags |= REG_EXTENDED;
 907                 if (O_ISSET(sp, O_IGNORECASE))
 908                         reflags |= REG_ICASE;
 909                 if (O_ISSET(sp, O_ICLOWER))
 910                         goto iclower;
 911         }
 912         if (LF_ISSET(SEARCH_ICL)) {
 913 iclower:        for (p = ptrn, len = plen; len > 0; ++p, --len)
 914                         if (ISUPPER((UCHAR_T)*p))
 915                                 break;
 916                 if (len == 0)
 917                         reflags |= REG_ICASE;
 918         }
 919
 920         /* If we're replacing a saved value, clear the old one. */
 921         if (LF_ISSET(SEARCH_CSEARCH) && F_ISSET(sp, SC_RE_SEARCH)) {
 922                 regfree(&sp->re_c);
 923                 F_CLR(sp, SC_RE_SEARCH);
 924         }
 925         if (LF_ISSET(SEARCH_CSUBST) && F_ISSET(sp, SC_RE_SUBST)) {
 926                 regfree(&sp->subre_c);
 927                 F_CLR(sp, SC_RE_SUBST);
 928         }
 929
 930         /*
 931          * If we're saving the string, it's a pattern we haven't seen before,
 932          * so convert the vi-style RE's to POSIX 1003.2 RE's.  Save a copy for
 933          * later recompilation.   Free any previously saved value.
 934          */
 935         if (ptrnp != NULL) {
 936                 replaced = 0;
 937                 if (LF_ISSET(SEARCH_CSCOPE)) {
 938                         if (re_cscope_conv(sp, &ptrn, &plen, &replaced))
 939                                 return (1);
 940                         /*
 941                          * XXX
 942                          * Currently, the match-any-<blank> expression used in
 943                          * re_cscope_conv() requires extended RE's.  This may
 944                          * not be right or safe.
 945                          */
 946                         reflags |= REG_EXTENDED;
 947                 } else if (LF_ISSET(SEARCH_TAG)) {
 948                         if (re_tag_conv(sp, &ptrn, &plen, &replaced))
 949                                 return (1);
 950                 } else if (!LF_ISSET(SEARCH_LITERAL))
 951                         if (re_conv(sp, &ptrn, &plen, &replaced))
 952                                 return (1);
 953
 954                 /* Discard previous pattern. */
 955                 if (*ptrnp != NULL) {
 956                         free(*ptrnp);
 957                         *ptrnp = NULL;
 958                 }
 959                 if (lenp != NULL)
 960                         *lenp = plen;
 961
 962                 /*
 963                  * Copy the string into allocated memory.
 964                  *
 965                  * XXX
 966                  * Regcomp isn't 8-bit clean, so the pattern is nul-terminated
 967                  * for now.  There's just no other solution.
 968                  */
 969                 MALLOC(sp, *ptrnp, CHAR_T *, (plen + 1) * sizeof(CHAR_T));
 970                 if (*ptrnp != NULL) {
 971                         MEMCPYW(*ptrnp, ptrn, plen);
 972                         (*ptrnp)[plen] = '\0';
 973                 }
 974
 975                 /* Free up conversion-routine-allocated memory. */
 976                 if (replaced)
 977                         FREE_SPACEW(sp, ptrn, 0);
 978
 979                 if (*ptrnp == NULL)
 980                         return (1);
 981
 982                 ptrn = *ptrnp;
 983         }
 984
 985         /*
 986          * XXX
 987          * Regcomp isn't 8-bit clean, so we just lost if the pattern
 988          * contained a nul.  Bummer!
 989          */
 990         if ((rval = regcomp(rep, ptrn, /* plen, */ reflags)) != 0) {
 991                 if (LF_ISSET(SEARCH_MSG))
 992                         re_error(sp, rval, rep);
 993                 return (1);
 994         }
 995
 996         if (LF_ISSET(SEARCH_CSEARCH))
 997                 F_SET(sp, SC_RE_SEARCH);
 998         if (LF_ISSET(SEARCH_CSUBST))
 999                 F_SET(sp, SC_RE_SUBST);
1000
1001         return (0);
1002 }
1003
1004 /*
1005  * re_conv --
1006  *      Convert vi's regular expressions into something that the
1007  *      the POSIX 1003.2 RE functions can handle.
1008  *
1009  * There are three conversions we make to make vi's RE's (specifically
1010  * the global, search, and substitute patterns) work with POSIX RE's.
1011  *
1012  * 1: If O_MAGIC is not set, strip backslashes from the magic character
1013  *    set (.[*~) that have them, and add them to the ones that don't.
1014  * 2: If O_MAGIC is not set, the string "\~" is replaced with the text
1015  *    from the last substitute command's replacement string.  If O_MAGIC
1016  *    is set, it's the string "~".
1017  * 3: The pattern \<ptrn\> does "word" searches, convert it to use the
1018  *    new RE escapes.
1019  *
1020  * !!!/XXX
1021  * This doesn't exactly match the historic behavior of vi because we do
1022  * the ~ substitution before calling the RE engine, so magic characters
1023  * in the replacement string will be expanded by the RE engine, and they
1024  * weren't historically.  It's a bug.
1025  */
1026 static int
1027 re_conv(SCR *sp, CHAR_T **ptrnp, size_t *plenp, int *replacedp)
1028 {
1029         size_t blen, len, needlen;
1030         int magic;
1031         CHAR_T *bp, *p, *t;
1032
1033         /*
1034          * First pass through, we figure out how much space we'll need.
1035          * We do it in two passes, on the grounds that most of the time
1036          * the user is doing a search and won't have magic characters.
1037          * That way we can skip most of the memory allocation and copies.
1038          */
1039         magic = 0;
1040         for (p = *ptrnp, len = *plenp, needlen = 0; len > 0; ++p, --len)
1041                 switch (*p) {
1042                 case '\\':
1043                         if (len > 1) {
1044                                 --len;
1045                                 switch (*++p) {
1046                                 case '<':
1047                                         magic = 1;
1048                                         needlen += RE_WSTART_LEN + 1;
1049                                         break;
1050                                 case '>':
1051                                         magic = 1;
1052                                         needlen += RE_WSTOP_LEN + 1;
1053                                         break;
1054                                 case '~':
1055                                         if (!O_ISSET(sp, O_MAGIC)) {
1056                                                 magic = 1;
1057                                                 needlen += sp->repl_len;
1058                                         }
1059                                         break;
1060                                 case '.':
1061                                 case '[':
1062                                 case '*':
1063                                         if (!O_ISSET(sp, O_MAGIC)) {
1064                                                 magic = 1;
1065                                                 needlen += 1;
1066                                         }
1067                                         break;
1068                                 default:
1069                                         needlen += 2;
1070                                 }
1071                         } else
1072                                 needlen += 1;
1073                         break;
1074                 case '~':
1075                         if (O_ISSET(sp, O_MAGIC)) {
1076                                 magic = 1;
1077                                 needlen += sp->repl_len;
1078                         }
1079                         break;
1080                 case '.':
1081                 case '[':
1082                 case '*':
1083                         if (!O_ISSET(sp, O_MAGIC)) {
1084                                 magic = 1;
1085                                 needlen += 2;
1086                         }
1087                         break;
1088                 default:
1089                         needlen += 1;
1090                         break;
1091                 }
1092
1093         if (!magic) {
1094                 *replacedp = 0;
1095                 return (0);
1096         }
1097
1098         /* Get enough memory to hold the final pattern. */
1099         *replacedp = 1;
1100         GET_SPACE_RETW(sp, bp, blen, needlen);
1101
1102         for (p = *ptrnp, len = *plenp, t = bp; len > 0; ++p, --len)
1103                 switch (*p) {
1104                 case '\\':
1105                         if (len > 1) {
1106                                 --len;
1107                                 switch (*++p) {
1108                                 case '<':
1109                                         MEMCPY(t,
1110                                             RE_WSTART, RE_WSTART_LEN);
1111                                         t += RE_WSTART_LEN;
1112                                         break;
1113                                 case '>':
1114                                         MEMCPY(t,
1115                                             RE_WSTOP, RE_WSTOP_LEN);
1116                                         t += RE_WSTOP_LEN;
1117                                         break;
1118                                 case '~':
1119                                         if (O_ISSET(sp, O_MAGIC))
1120                                                 *t++ = '~';
1121                                         else {
1122                                                 MEMCPYW(t,
1123                                                     sp->repl, sp->repl_len);
1124                                                 t += sp->repl_len;
1125                                         }
1126                                         break;
1127                                 case '.':
1128                                 case '[':
1129                                 case '*':
1130                                         if (O_ISSET(sp, O_MAGIC))
1131                                                 *t++ = '\\';
1132                                         *t++ = *p;
1133                                         break;
1134                                 default:
1135                                         *t++ = '\\';
1136                                         *t++ = *p;
1137                                 }
1138                         } else
1139                                 *t++ = '\\';
1140                         break;
1141                 case '~':
1142                         if (O_ISSET(sp, O_MAGIC)) {
1143                                 MEMCPYW(t, sp->repl, sp->repl_len);
1144                                 t += sp->repl_len;
1145                         } else
1146                                 *t++ = '~';
1147                         break;
1148                 case '.':
1149                 case '[':
1150                 case '*':
1151                         if (!O_ISSET(sp, O_MAGIC))
1152                                 *t++ = '\\';
1153                         *t++ = *p;
1154                         break;
1155                 default:
1156                         *t++ = *p;
1157                         break;
1158                 }
1159
1160         *ptrnp = bp;
1161         *plenp = t - bp;
1162         return (0);
1163 }
1164
1165 /*
1166  * re_tag_conv --
1167  *      Convert a tags search path into something that the POSIX
1168  *      1003.2 RE functions can handle.
1169  */
1170 static int
1171 re_tag_conv(SCR *sp, CHAR_T **ptrnp, size_t *plenp, int *replacedp)
1172 {
1173         size_t blen, len;
1174         int lastdollar;
1175         CHAR_T *bp, *p, *t;
1176
1177         len = *plenp;
1178
1179         /* Max memory usage is 2 times the length of the string. */
1180         *replacedp = 1;
1181         GET_SPACE_RETW(sp, bp, blen, len * 2);
1182
1183         p = *ptrnp;
1184         t = bp;
1185
1186         /* If the last character is a '/' or '?', we just strip it. */
1187         if (len > 0 && (p[len - 1] == '/' || p[len - 1] == '?'))
1188                 --len;
1189
1190         /* If the next-to-last or last character is a '$', it's magic. */
1191         if (len > 0 && p[len - 1] == '$') {
1192                 --len;
1193                 lastdollar = 1;
1194         } else
1195                 lastdollar = 0;
1196
1197         /* If the first character is a '/' or '?', we just strip it. */
1198         if (len > 0 && (p[0] == '/' || p[0] == '?')) {
1199                 ++p;
1200                 --len;
1201         }
1202
1203         /* If the first or second character is a '^', it's magic. */
1204         if (p[0] == '^') {
1205                 *t++ = *p++;
1206                 --len;
1207         }
1208
1209         /*
1210          * Escape every other magic character we can find, meanwhile stripping
1211          * the backslashes ctags inserts when escaping the search delimiter
1212          * characters.
1213          */
1214         for (; len > 0; --len) {
1215                 if (p[0] == '\\' && (p[1] == '/' || p[1] == '?')) {
1216                         ++p;
1217                         --len;
1218                 } else if (strchr("^.[]$*", p[0]))
1219                         *t++ = '\\';
1220                 *t++ = *p++;
1221         }
1222         if (lastdollar)
1223                 *t++ = '$';
1224
1225         *ptrnp = bp;
1226         *plenp = t - bp;
1227         return (0);
1228 }
1229
1230 /*
1231  * re_cscope_conv --
1232  *       Convert a cscope search path into something that the POSIX
1233  *      1003.2 RE functions can handle.
1234  */
1235 static int
1236 re_cscope_conv(SCR *sp, CHAR_T **ptrnp, size_t *plenp, int *replacedp)
1237 {
1238         size_t blen, len, nspaces;
1239         CHAR_T *bp, *t;
1240         CHAR_T *p;
1241         const CHAR_T *wp;
1242         size_t wlen;
1243
1244         /*
1245          * Each space in the source line printed by cscope represents an
1246          * arbitrary sequence of spaces, tabs, and comments.
1247          */
1248 #define CSCOPE_RE_SPACE         "([ \t]|/\\*([^*]|\\*/)*\\*/)*"
1249 #define CSCOPE_LEN      sizeof(CSCOPE_RE_SPACE) - 1
1250         CHAR2INT(sp, CSCOPE_RE_SPACE, CSCOPE_LEN, wp, wlen);
1251         for (nspaces = 0, p = *ptrnp, len = *plenp; len > 0; ++p, --len)
1252                 if (*p == ' ')
1253                         ++nspaces;
1254
1255         /*
1256          * Allocate plenty of space:
1257          *      the string, plus potential escaping characters;
1258          *      nspaces + 2 copies of CSCOPE_RE_SPACE;
1259          *      ^, $, nul terminator characters.
1260          */
1261         *replacedp = 1;
1262         len = (p - *ptrnp) * 2 + (nspaces + 2) * sizeof(CSCOPE_RE_SPACE) + 3;
1263         GET_SPACE_RETW(sp, bp, blen, len);
1264
1265         p = *ptrnp;
1266         t = bp;
1267
1268         *t++ = '^';
1269         MEMCPYW(t, wp, wlen);
1270         t += wlen;
1271
1272         for (len = *plenp; len > 0; ++p, --len)
1273                 if (*p == ' ') {
1274                         MEMCPYW(t, wp, wlen);
1275                         t += wlen;
1276                 } else {
1277                         if (strchr("\\^.[]$*+?()|{}", *p))
1278                                 *t++ = '\\';
1279                         *t++ = *p;
1280                 }
1281
1282         MEMCPYW(t, wp, wlen);
1283         t += wlen;
1284         *t++ = '$';
1285
1286         *ptrnp = bp;
1287         *plenp = t - bp;
1288         return (0);
1289 }
1290
1291 /*
1292  * re_error --
1293  *      Report a regular expression error.
1294  *
1295  * PUBLIC: void re_error __P((SCR *, int, regex_t *));
1296  */
1297 void
1298 re_error(SCR *sp, int errcode, regex_t *preg)
1299 {
1300         size_t sz;
1301         char *oe;
1302
1303         sz = regerror(errcode, preg, NULL, 0);
1304         if ((oe = malloc(sz)) == NULL)
1305                 msgq(sp, M_SYSERR, NULL);
1306         else {
1307                 (void)regerror(errcode, preg, oe, sz);
1308                 msgq(sp, M_ERR, "RE error: %s", oe);
1309                 free(oe);
1310         }
1311 }
1312
1313 /*
1314  * re_sub --
1315  *      Do the substitution for a regular expression.
1316  */
1317 static int
1318 re_sub(SCR *sp, CHAR_T *ip, CHAR_T **lbp, size_t *lbclenp, size_t *lblenp, regmatch_t *match)
1319
1320                                         /* Input line. */
1321
1322
1323
1324 {
1325         enum { C_NOT_SET, C_LOWER, C_ONE_LOWER, C_ONE_UPPER, C_UPPER } conv;
1326         size_t lbclen, lblen;           /* Local copies. */
1327         size_t mlen;                    /* Match length. */
1328         size_t rpl;                     /* Remaining replacement length. */
1329         CHAR_T *rp;                     /* Replacement pointer. */
1330         int ch;
1331         int no;                         /* Match replacement offset. */
1332         CHAR_T *p, *t;                  /* Buffer pointers. */
1333         CHAR_T *lb;                     /* Local copies. */
1334
1335         lb = *lbp;                      /* Get local copies. */
1336         lbclen = *lbclenp;
1337         lblen = *lblenp;
1338
1339         /*
1340          * QUOTING NOTE:
1341          *
1342          * There are some special sequences that vi provides in the
1343          * replacement patterns.
1344          *       & string the RE matched (\& if nomagic set)
1345          *      \# n-th regular subexpression
1346          *      \E end \U, \L conversion
1347          *      \e end \U, \L conversion
1348          *      \l convert the next character to lower-case
1349          *      \L convert to lower-case, until \E, \e, or end of replacement
1350          *      \u convert the next character to upper-case
1351          *      \U convert to upper-case, until \E, \e, or end of replacement
1352          *
1353          * Otherwise, since this is the lowest level of replacement, discard
1354          * all escaping characters.  This (hopefully) matches historic practice.
1355          */
1356 #define OUTCH(ch, nltrans) {                                            \
1357         ARG_CHAR_T __ch = (ch);                                         \
1358         e_key_t __value = KEY_VAL(sp, __ch);                            \
1359         if (nltrans && (__value == K_CR || __value == K_NL)) {          \
1360                 NEEDNEWLINE(sp);                                        \
1361                 sp->newl[sp->newl_cnt++] = lbclen;                      \
1362         } else if (conv != C_NOT_SET) {                                 \
1363                 switch (conv) {                                         \
1364                 case C_ONE_LOWER:                                       \
1365                         conv = C_NOT_SET;                               \
1366                         /* FALLTHROUGH */                               \
1367                 case C_LOWER:                                           \
1368                         if (ISUPPER(__ch))                              \
1369                                 __ch = TOLOWER(__ch);                   \
1370                         break;                                          \
1371                 case C_ONE_UPPER:                                       \
1372                         conv = C_NOT_SET;                               \
1373                         /* FALLTHROUGH */                               \
1374                 case C_UPPER:                                           \
1375                         if (ISLOWER(__ch))                              \
1376                                 __ch = TOUPPER(__ch);                   \
1377                         break;                                          \
1378                 default:                                                \
1379                         abort();                                        \
1380                 }                                                       \
1381         }                                                               \
1382         NEEDSP(sp, 1, p);                                               \
1383         *p++ = __ch;                                                    \
1384         ++lbclen;                                                       \
1385 }
1386         conv = C_NOT_SET;
1387         for (rp = sp->repl, rpl = sp->repl_len, p = lb + lbclen; rpl--;) {
1388                 switch (ch = *rp++) {
1389                 case '&':
1390                         if (O_ISSET(sp, O_MAGIC)) {
1391                                 no = 0;
1392                                 goto subzero;
1393                         }
1394                         break;
1395                 case '\\':
1396                         if (rpl == 0)
1397                                 break;
1398                         --rpl;
1399                         switch (ch = *rp) {
1400                         case '&':
1401                                 ++rp;
1402                                 if (!O_ISSET(sp, O_MAGIC)) {
1403                                         no = 0;
1404                                         goto subzero;
1405                                 }
1406                                 break;
1407                         case '0': case '1': case '2': case '3': case '4':
1408                         case '5': case '6': case '7': case '8': case '9':
1409                                 no = *rp++ - '0';
1410 subzero:                        if (match[no].rm_so == -1 ||
1411                                     match[no].rm_eo == -1)
1412                                         break;
1413                                 mlen = match[no].rm_eo - match[no].rm_so;
1414                                 for (t = ip + match[no].rm_so; mlen--; ++t)
1415                                         OUTCH((UCHAR_T)*t, 0);
1416                                 continue;
1417                         case 'e':
1418                         case 'E':
1419                                 ++rp;
1420                                 conv = C_NOT_SET;
1421                                 continue;
1422                         case 'l':
1423                                 ++rp;
1424                                 conv = C_ONE_LOWER;
1425                                 continue;
1426                         case 'L':
1427                                 ++rp;
1428                                 conv = C_LOWER;
1429                                 continue;
1430                         case 'u':
1431                                 ++rp;
1432                                 conv = C_ONE_UPPER;
1433                                 continue;
1434                         case 'U':
1435                                 ++rp;
1436                                 conv = C_UPPER;
1437                                 continue;
1438                         default:
1439                                 ++rp;
1440                                 break;
1441                         }
1442                 }
1443                 OUTCH(ch, 1);
1444         }
1445
1446         *lbp = lb;                      /* Update caller's information. */
1447         *lbclenp = lbclen;
1448         *lblenp = lblen;
1449         return (0);
1450 }