dist/nvi/ex/ex_subst.c

   1 /*      $NetBSD: ex_subst.c,v 1.2 2008/12/05 22:51:42 christos Exp $ */
   2
   3 /*-
   4  * Copyright (c) 1992, 1993, 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  * Copyright (c) 1992, 1993, 1994, 1995, 1996
   7  *      Keith Bostic.  All rights reserved.
   8  *
   9  * See the LICENSE file for redistribution information.
  10  */
  11
  12 #include "config.h"
  13
  14 #ifndef lint
  15 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";
  16 #endif /* not lint */
  17
  18 #include <sys/types.h>
  19 #include <sys/queue.h>
  20 #include <sys/time.h>
  21
  22 #include <bitstring.h>
  23 #include <ctype.h>
  24 #include <errno.h>
  25 #include <limits.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <unistd.h>
  30
  31 #include "../common/common.h"
  32 #include "../vi/vi.h"
  33
  34 #define SUB_FIRST       0x01            /* The 'r' flag isn't reasonable. */
  35 #define SUB_MUSTSETR    0x02            /* The 'r' flag is required. */
  36
  37 static int re_conv __P((SCR *, CHAR_T **, size_t *, int *));
  38 static int re_cscope_conv __P((SCR *, CHAR_T **, size_t *, int *));
  39 static int re_sub __P((SCR *,
  40                 CHAR_T *, CHAR_T **, size_t *, size_t *, regmatch_t [10]));
  41 static int re_tag_conv __P((SCR *, CHAR_T **, size_t *, int *));
  42 static int s __P((SCR *, EXCMD *, CHAR_T *, regex_t *, u_int));
  43
  44 /*
  45  * ex_s --
  46  *      [line [,line]] s[ubstitute] [[/;]pat[/;]/repl[/;] [cgr] [count] [#lp]]
  47  *
  48  *      Substitute on lines matching a pattern.
  49  *
  50  * PUBLIC: int ex_s __P((SCR *, EXCMD *));
  51  */
  52 int
  53 ex_s(SCR *sp, EXCMD *cmdp)
  54 {
  55         regex_t *re;
  56         size_t blen, len;
  57         u_int flags;
  58         int delim;
  59         CHAR_T *bp, *p, *ptrn, *rep, *t;
  60
  61         /*
  62          * Skip leading white space.
  63          *
  64          * !!!
  65          * Historic vi allowed any non-alphanumeric to serve as the
  66          * substitution command delimiter.
  67          *
  68          * !!!
  69          * If the arguments are empty, it's the same as &, i.e. we
  70          * repeat the last substitution.
  71          */
  72         if (cmdp->argc == 0)
  73                 goto subagain;
  74         for (p = cmdp->argv[0]->bp,
  75             len = cmdp->argv[0]->len; len > 0; --len, ++p) {
  76                 if (!isblank(*p))
  77                         break;
  78         }
  79         if (len == 0)
  80 subagain:       return (ex_subagain(sp, cmdp));
  81
  82         delim = *p++;
  83         if (isalnum(delim) || delim == '\\')
  84                 return (s(sp, cmdp, p, &sp->subre_c, SUB_MUSTSETR));
  85
  86         /*
  87          * !!!
  88          * The full-blown substitute command reset the remembered
  89          * state of the 'c' and 'g' suffices.
  90          */
  91         sp->c_suffix = sp->g_suffix = 0;
  92
  93         /*
  94          * Get the pattern string, toss escaping characters.
  95          *
  96          * !!!
  97          * Historic vi accepted any of the following forms:
  98          *
  99          *      :s/abc/def/             change "abc" to "def"
 100          *      :s/abc/def              change "abc" to "def"
 101          *      :s/abc/                 delete "abc"
 102          *      :s/abc                  delete "abc"
 103          *
 104          * QUOTING NOTE:
 105          *
 106          * Only toss an escaping character if it escapes a delimiter.
 107          * This means that "s/A/\\\\f" replaces "A" with "\\f".  It
 108          * would be nice to be more regular, i.e. for each layer of
 109          * escaping a single escaping character is removed, but that's
 110          * not how the historic vi worked.
 111          */
 112         for (ptrn = t = p;;) {
 113                 if (p[0] == '\0' || p[0] == delim) {
 114                         if (p[0] == delim)
 115                                 ++p;
 116                         /*
 117                          * !!!
 118                          * Nul terminate the pattern string -- it's passed
 119                          * to regcomp which doesn't understand anything else.
 120                          */
 121                         *t = '\0';
 122                         break;
 123                 }
 124                 if (p[0] == '\\') {
 125                         if (p[1] == delim)
 126                                 ++p;
 127                         else if (p[1] == '\\')
 128                                 *t++ = *p++;
 129                 }
 130                 *t++ = *p++;
 131         }
 132
 133         /*
 134          * If the pattern string is empty, use the last RE (not just the
 135          * last substitution RE).
 136          */
 137         if (*ptrn == '\0') {
 138                 if (sp->re == NULL) {
 139                         ex_emsg(sp, NULL, EXM_NOPREVRE);
 140                         return (1);
 141                 }
 142
 143                 /* Re-compile the RE if necessary. */
 144                 if (!F_ISSET(sp, SC_RE_SEARCH) &&
 145                     re_compile(sp, sp->re, sp->re_len,
 146                     NULL, NULL, &sp->re_c, SEARCH_CSEARCH | SEARCH_MSG))
 147                         return (1);
 148                 flags = 0;
 149         } else {
 150                 /*
 151                  * !!!
 152                  * Compile the RE.  Historic practice is that substitutes set
 153                  * the search direction as well as both substitute and search
 154                  * RE's.  We compile the RE twice, as we don't want to bother
 155                  * ref counting the pattern string and (opaque) structure.
 156                  */
 157                 if (re_compile(sp, ptrn, t - ptrn, &sp->re,
 158                     &sp->re_len, &sp->re_c, SEARCH_CSEARCH | SEARCH_MSG))
 159                         return (1);
 160                 if (re_compile(sp, ptrn, t - ptrn, &sp->subre,
 161                     &sp->subre_len, &sp->subre_c, SEARCH_CSUBST | SEARCH_MSG))
 162                         return (1);
 163
 164                 flags = SUB_FIRST;
 165                 sp->searchdir = FORWARD;
 166         }
 167         re = &sp->re_c;
 168
 169         /*
 170          * Get the replacement string.
 171          *
 172          * The special character & (\& if O_MAGIC not set) matches the
 173          * entire RE.  No handling of & is required here, it's done by
 174          * re_sub().
 175          *
 176          * The special character ~ (\~ if O_MAGIC not set) inserts the
 177          * previous replacement string into this replacement string.
 178          * Count ~'s to figure out how much space we need.  We could
 179          * special case nonexistent last patterns or whether or not
 180          * O_MAGIC is set, but it's probably not worth the effort.
 181          *
 182          * QUOTING NOTE:
 183          *
 184          * Only toss an escaping character if it escapes a delimiter or
 185          * if O_MAGIC is set and it escapes a tilde.
 186          *
 187          * !!!
 188          * If the entire replacement pattern is "%", then use the last
 189          * replacement pattern.  This semantic was added to vi in System
 190          * V and then percolated elsewhere, presumably around the time
 191          * that it was added to their version of ed(1).
 192          */
 193         if (p[0] == L('\0') || p[0] == delim) {
 194                 if (p[0] == delim)
 195                         ++p;
 196                 if (sp->repl != NULL)
 197                         free(sp->repl);
 198                 sp->repl = NULL;
 199                 sp->repl_len = 0;
 200         } else if (p[0] == L('%') && (p[1] == L('\0') || p[1] == delim))
 201                 p += p[1] == delim ? 2 : 1;
 202         else {
 203                 for (rep = p, len = 0;
 204                     p[0] != L('\0') && p[0] != delim; ++p, ++len)
 205                         if (p[0] == L('~'))
 206                                 len += sp->repl_len;
 207                 GET_SPACE_RETW(sp, bp, blen, len);
 208                 for (t = bp, len = 0, p = rep;;) {
 209                         if (p[0] == L('\0') || p[0] == delim) {
 210                                 if (p[0] == delim)
 211                                         ++p;
 212                                 break;
 213                         }
 214                         if (p[0] == L('\\')) {
 215                                 if (p[1] == delim)
 216                                         ++p;
 217                                 else if (p[1] == L('\\')) {
 218                                         *t++ = *p++;
 219                                         ++len;
 220                                 } else if (p[1] == L('~')) {
 221                                         ++p;
 222                                         if (!O_ISSET(sp, O_MAGIC))
 223                                                 goto tilde;
 224                                 }
 225                         } else if (p[0] == L('~') && O_ISSET(sp, O_MAGIC)) {
 226 tilde:                          ++p;
 227                                 MEMCPYW(t, sp->repl, sp->repl_len);
 228                                 t += sp->repl_len;
 229                                 len += sp->repl_len;
 230                                 continue;
 231                         }
 232                         *t++ = *p++;
 233                         ++len;
 234                 }
 235                 if ((sp->repl_len = len) != 0) {
 236                         if (sp->repl != NULL)
 237                                 free(sp->repl);
 238                         if ((sp->repl = malloc(len * sizeof(CHAR_T))) == NULL) {
 239                                 msgq(sp, M_SYSERR, NULL);
 240                                 FREE_SPACEW(sp, bp, blen);
 241                                 return (1);
 242                         }
 243                         MEMCPYW(sp->repl, bp, len);
 244                 }
 245                 FREE_SPACEW(sp, bp, blen);
 246         }
 247         return (s(sp, cmdp, p, re, flags));
 248 }
 249
 250 /*
 251  * ex_subagain --
 252  *      [line [,line]] & [cgr] [count] [#lp]]
 253  *
 254  *      Substitute using the last substitute RE and replacement pattern.
 255  *
 256  * PUBLIC: int ex_subagain __P((SCR *, EXCMD *));
 257  */
 258 int
 259 ex_subagain(SCR *sp, EXCMD *cmdp)
 260 {
 261         if (sp->subre == NULL) {
 262                 ex_emsg(sp, NULL, EXM_NOPREVRE);
 263                 return (1);
 264         }
 265         if (!F_ISSET(sp, SC_RE_SUBST) &&
 266             re_compile(sp, sp->subre, sp->subre_len,
 267             NULL, NULL, &sp->subre_c, SEARCH_CSUBST | SEARCH_MSG))
 268                 return (1);
 269         return (s(sp,
 270             cmdp, cmdp->argc ? cmdp->argv[0]->bp : NULL, &sp->subre_c, 0));
 271 }
 272
 273 /*
 274  * ex_subtilde --
 275  *      [line [,line]] ~ [cgr] [count] [#lp]]
 276  *
 277  *      Substitute using the last RE and last substitute replacement pattern.
 278  *
 279  * PUBLIC: int ex_subtilde __P((SCR *, EXCMD *));
 280  */
 281 int
 282 ex_subtilde(SCR *sp, EXCMD *cmdp)
 283 {
 284         if (sp->re == NULL) {
 285                 ex_emsg(sp, NULL, EXM_NOPREVRE);
 286                 return (1);
 287         }
 288         if (!F_ISSET(sp, SC_RE_SEARCH) && re_compile(sp, sp->re,
 289             sp->re_len, NULL, NULL, &sp->re_c, SEARCH_CSEARCH | SEARCH_MSG))
 290                 return (1);
 291         return (s(sp,
 292             cmdp, cmdp->argc ? cmdp->argv[0]->bp : NULL, &sp->re_c, 0));
 293 }
 294
 295 /*
 296  * s --
 297  * Do the substitution.  This stuff is *really* tricky.  There are lots of
 298  * special cases, and general nastiness.  Don't mess with it unless you're
 299  * pretty confident.
 300  *
 301  * The nasty part of the substitution is what happens when the replacement
 302  * string contains newlines.  It's a bit tricky -- consider the information
 303  * that has to be retained for "s/f\(o\)o/^M\1^M\1/".  The solution here is
 304  * to build a set of newline offsets which we use to break the line up later,
 305  * when the replacement is done.  Don't change it unless you're *damned*
 306  * confident.
 307  */
 308 #define NEEDNEWLINE(sp) {                                               \
 309         if (sp->newl_len == sp->newl_cnt) {                             \
 310                 sp->newl_len += 25;                                     \
 311                 REALLOC(sp, sp->newl, size_t *,                         \
 312                     sp->newl_len * sizeof(size_t));                     \
 313                 if (sp->newl == NULL) {                                 \
 314                         sp->newl_len = 0;                               \
 315                         return (1);                                     \
 316                 }                                                       \
 317         }                                                               \
 318 }
 319
 320 #define BUILD(sp, l, len) {                                             \
 321         if (lbclen + (len) > lblen) {                                   \
 322                 lblen += MAX(lbclen + (len), 256);                      \
 323                 REALLOC(sp, lb, CHAR_T *, lblen * sizeof(CHAR_T));      \
 324                 if (lb == NULL) {                                       \
 325                         lbclen = 0;                                     \
 326                         return (1);                                     \
 327                 }                                                       \
 328         }                                                               \
 329         MEMCPYW(lb + lbclen, l, len);                                   \
 330         lbclen += len;                                                  \
 331 }
 332
 333 #define NEEDSP(sp, len, pnt) {                                          \
 334         if (lbclen + (len) > lblen) {                                   \
 335                 lblen += MAX(lbclen + (len), 256);                      \
 336                 REALLOC(sp, lb, CHAR_T *, lblen * sizeof(CHAR_T));      \
 337                 if (lb == NULL) {                                       \
 338                         lbclen = 0;                                     \
 339                         return (1);                                     \
 340                 }                                                       \
 341                 pnt = lb + lbclen;                                      \
 342         }                                                               \
 343 }
 344
 345 static int
 346 s(SCR *sp, EXCMD *cmdp, CHAR_T *st, regex_t *re, u_int flags)
 347 {
 348         EVENT ev;
 349         MARK from, to;
 350         TEXTH tiq;
 351         db_recno_t elno, lno, slno;
 352         u_long ul;
 353         regmatch_t match[10];
 354         size_t blen, cnt, last, lbclen, lblen, len, llen;
 355         size_t offset, saved_offset, scno;
 356         int cflag, lflag, nflag, pflag, rflag;
 357         int didsub, do_eol_match, eflags, empty_ok, eval;
 358         int linechanged, matched, quit, rval;
 359         CHAR_T *lb, *bp;
 360         enum nresult nret;
 361
 362         NEEDFILE(sp, cmdp);
 363
 364         slno = sp->lno;
 365         scno = sp->cno;
 366
 367         /*
 368          * !!!
 369          * Historically, the 'g' and 'c' suffices were always toggled as flags,
 370          * so ":s/A/B/" was the same as ":s/A/B/ccgg".  If O_EDCOMPATIBLE was
 371          * not set, they were initialized to 0 for all substitute commands.  If
 372          * O_EDCOMPATIBLE was set, they were initialized to 0 only if the user
 373          * specified substitute/replacement patterns (see ex_s()).
 374          */
 375         if (!O_ISSET(sp, O_EDCOMPATIBLE))
 376                 sp->c_suffix = sp->g_suffix = 0;
 377
 378         /*
 379          * Historic vi permitted the '#', 'l' and 'p' options in vi mode, but
 380          * it only displayed the last change.  I'd disallow them, but they are
 381          * useful in combination with the [v]global commands.  In the current
 382          * model the problem is combining them with the 'c' flag -- the screen
 383          * would have to flip back and forth between the confirm screen and the
 384          * ex print screen, which would be pretty awful.  We do display all
 385          * changes, though, for what that's worth.
 386          *
 387          * !!!
 388          * Historic vi was fairly strict about the order of "options", the
 389          * count, and "flags".  I'm somewhat fuzzy on the difference between
 390          * options and flags, anyway, so this is a simpler approach, and we
 391          * just take it them in whatever order the user gives them.  (The ex
 392          * usage statement doesn't reflect this.)
 393          */
 394         cflag = lflag = nflag = pflag = rflag = 0;
 395         if (st == NULL)
 396                 goto noargs;
 397         for (lno = OOBLNO; *st != '\0'; ++st)
 398                 switch (*st) {
 399                 case ' ':
 400                 case '\t':
 401                         continue;
 402                 case '+':
 403                         ++cmdp->flagoff;
 404                         break;
 405                 case '-':
 406                         --cmdp->flagoff;
 407                         break;
 408                 case '0': case '1': case '2': case '3': case '4':
 409                 case '5': case '6': case '7': case '8': case '9':
 410                         if (lno != OOBLNO)
 411                                 goto usage;
 412                         errno = 0;
 413                         nret = nget_uslong(sp, &ul, st, &st, 10);
 414                         lno = ul;
 415                         if (*st == '\0')                /* Loop increment correction. */
 416                                 --st;
 417                         if (nret != NUM_OK) {
 418                                 if (nret == NUM_OVER)
 419                                         msgq(sp, M_ERR, "153|Count overflow");
 420                                 else if (nret == NUM_UNDER)
 421                                         msgq(sp, M_ERR, "154|Count underflow");
 422                                 else
 423                                         msgq(sp, M_SYSERR, NULL);
 424                                 return (1);
 425                         }
 426                         /*
 427                          * In historic vi, the count was inclusive from the
 428                          * second address.
 429                          */
 430                         cmdp->addr1.lno = cmdp->addr2.lno;
 431                         cmdp->addr2.lno += lno - 1;
 432                         if (!db_exist(sp, cmdp->addr2.lno) &&
 433                             db_last(sp, &cmdp->addr2.lno))
 434                                 return (1);
 435                         break;
 436                 case '#':
 437                         nflag = 1;
 438                         break;
 439                 case 'c':
 440                         sp->c_suffix = !sp->c_suffix;
 441
 442                         /* Ex text structure initialization. */
 443                         if (F_ISSET(sp, SC_EX)) {
 444                                 memset(&tiq, 0, sizeof(TEXTH));
 445                                 CIRCLEQ_INIT(&tiq);
 446                         }
 447                         break;
 448                 case 'g':
 449                         sp->g_suffix = !sp->g_suffix;
 450                         break;
 451                 case 'l':
 452                         lflag = 1;
 453                         break;
 454                 case 'p':
 455                         pflag = 1;
 456                         break;
 457                 case 'r':
 458                         if (LF_ISSET(SUB_FIRST)) {
 459                                 msgq(sp, M_ERR,
 460                     "155|Regular expression specified; r flag meaningless");
 461                                 return (1);
 462                         }
 463                         if (!F_ISSET(sp, SC_RE_SEARCH)) {
 464                                 ex_emsg(sp, NULL, EXM_NOPREVRE);
 465                                 return (1);
 466                         }
 467                         rflag = 1;
 468                         re = &sp->re_c;
 469                         break;
 470                 default:
 471                         goto usage;
 472                 }
 473
 474         if (*st != '\0' || (!rflag && LF_ISSET(SUB_MUSTSETR))) {
 475 usage:          ex_emsg(sp, cmdp->cmd->usage, EXM_USAGE);
 476                 return (1);
 477         }
 478
 479 noargs: if (F_ISSET(sp, SC_VI) && sp->c_suffix && (lflag || nflag || pflag)) {
 480                 msgq(sp, M_ERR,
 481 "156|The #, l and p flags may not be combined with the c flag in vi mode");
 482                 return (1);
 483         }
 484
 485         /*
 486          * bp:          if interactive, line cache
 487          * blen:        if interactive, line cache length
 488          * lb:          build buffer pointer.
 489          * lbclen:      current length of built buffer.
 490          * lblen;       length of build buffer.
 491          */
 492         bp = lb = NULL;
 493         blen = lbclen = lblen = 0;
 494
 495         /* For each line... */
 496         lno = cmdp->addr1.lno == 0 ? 1 : cmdp->addr1.lno;
 497         for (matched = quit = 0,
 498             elno = cmdp->addr2.lno; !quit && lno <= elno; ++lno) {
 499
 500                 /* Someone's unhappy, time to stop. */
 501                 if (INTERRUPTED(sp))
 502                         break;
 503
 504                 /* Get the line. */
 505                 if (db_get(sp, lno, DBG_FATAL, &st, &llen))
 506                         goto err;
 507
 508                 /*
 509                  * Make a local copy if doing confirmation -- when calling
 510                  * the confirm routine we're likely to lose the cached copy.
 511                  */
 512                 if (sp->c_suffix) {
 513                         if (bp == NULL) {
 514                                 GET_SPACE_RETW(sp, bp, blen, llen);
 515                         } else
 516                                 ADD_SPACE_RETW(sp, bp, blen, llen);
 517                         MEMCPYW(bp, st, llen);
 518                         st = bp;
 519                 }
 520
 521                 /* Start searching from the beginning. */
 522                 offset = 0;
 523                 len = llen;
 524
 525                 /* Reset the build buffer offset. */
 526                 lbclen = 0;
 527
 528                 /* Reset empty match flag. */
 529                 empty_ok = 1;
 530
 531                 /*
 532                  * We don't want to have to do a setline if the line didn't
 533                  * change -- keep track of whether or not this line changed.
 534                  * If doing confirmations, don't want to keep setting the
 535                  * line if change is refused -- keep track of substitutions.
 536                  */
 537                 didsub = linechanged = 0;
 538
 539                 /* New line, do an EOL match. */
 540                 do_eol_match = 1;
 541
 542                 /* It's not nul terminated, but we pretend it is. */
 543                 eflags = REG_STARTEND;
 544
 545                 /*
 546                  * The search area is from st + offset to the EOL.
 547                  *
 548                  * Generally, match[0].rm_so is the offset of the start
 549                  * of the match from the start of the search, and offset
 550                  * is the offset of the start of the last search.
 551                  */
 552 nextmatch:      match[0].rm_so = 0;
 553                 match[0].rm_eo = len;
 554
 555                 /* Get the next match. */
 556                 eval = regexec(re, st + offset, 10, match, eflags);
 557
 558                 /*
 559                  * There wasn't a match or if there was an error, deal with
 560                  * it.  If there was a previous match in this line, resolve
 561                  * the changes into the database.  Otherwise, just move on.
 562                  */
 563                 if (eval == REG_NOMATCH)
 564                         goto endmatch;
 565                 if (eval != 0) {
 566                         re_error(sp, eval, re);
 567                         goto err;
 568                 }
 569                 matched = 1;
 570
 571                 /* Only the first search can match an anchored expression. */
 572                 eflags |= REG_NOTBOL;
 573
 574                 /*
 575                  * !!!
 576                  * It's possible to match 0-length strings -- for example, the
 577                  * command s;a*;X;, when matched against the string "aabb" will
 578                  * result in "XbXbX", i.e. the matches are "aa", the space
 579                  * between the b's and the space between the b's and the end of
 580                  * the string.  There is a similar space between the beginning
 581                  * of the string and the a's.  The rule that we use (because vi
 582                  * historically used it) is that any 0-length match, occurring
 583                  * immediately after a match, is ignored.  Otherwise, the above
 584                  * example would have resulted in "XXbXbX".  Another example is
 585                  * incorrectly using " *" to replace groups of spaces with one
 586                  * space.
 587                  *
 588                  * The way we do this is that if we just had a successful match,
 589                  * the starting offset does not skip characters, and the match
 590                  * is empty, ignore the match and move forward.  If there's no
 591                  * more characters in the string, we were attempting to match
 592                  * after the last character, so quit.
 593                  */
 594                 if (!empty_ok && match[0].rm_so == 0 && match[0].rm_eo == 0) {
 595                         empty_ok = 1;
 596                         if (len == 0)
 597                                 goto endmatch;
 598                         BUILD(sp, st + offset, 1)
 599                         ++offset;
 600                         --len;
 601                         goto nextmatch;
 602                 }
 603
 604                 /* Confirm change. */
 605                 if (sp->c_suffix) {
 606                         /*
 607                          * Set the cursor position for confirmation.  Note,
 608                          * if we matched on a '$', the cursor may be past
 609                          * the end of line.
 610                          */
 611                         from.lno = to.lno = lno;
 612                         from.cno = match[0].rm_so + offset;
 613                         to.cno = match[0].rm_eo + offset;
 614                         /*
 615                          * Both ex and vi have to correct for a change before
 616                          * the first character in the line.
 617                          */
 618                         if (llen == 0)
 619                                 from.cno = to.cno = 0;
 620                         if (F_ISSET(sp, SC_VI)) {
 621                                 /*
 622                                  * Only vi has to correct for a change after
 623                                  * the last character in the line.
 624                                  *
 625                                  * XXX
 626                                  * It would be nice to change the vi code so
 627                                  * that we could display a cursor past EOL.
 628                                  */
 629                                 if (to.cno >= llen)
 630                                         to.cno = llen - 1;
 631                                 if (from.cno >= llen)
 632                                         from.cno = llen - 1;
 633
 634                                 sp->lno = from.lno;
 635                                 sp->cno = from.cno;
 636                                 if (vs_refresh(sp, 1))
 637                                         goto err;
 638
 639                                 vs_update(sp, msg_cat(sp,
 640                                     "169|Confirm change? [n]", NULL), NULL);
 641
 642                                 if (v_event_get(sp, &ev, 0, 0))
 643                                         goto err;
 644                                 switch (ev.e_event) {
 645                                 case E_CHARACTER:
 646                                         break;
 647                                 case E_EOF:
 648                                 case E_ERR:
 649                                 case E_INTERRUPT:
 650                                         goto lquit;
 651                                 default:
 652                                         v_event_err(sp, &ev);
 653                                         goto lquit;
 654                                 }
 655                         } else {
 656                                 if (ex_print(sp, cmdp, &from, &to, 0) ||
 657                                     ex_scprint(sp, &from, &to))
 658                                         goto lquit;
 659                                 if (ex_txt(sp, &tiq, 0, TXT_CR))
 660                                         goto err;
 661                                 ev.e_c = tiq.cqh_first->lb[0];
 662                         }
 663
 664                         switch (ev.e_c) {
 665                         case CH_YES:
 666                                 break;
 667                         default:
 668                         case CH_NO:
 669                                 didsub = 0;
 670                                 BUILD(sp, st + offset, match[0].rm_eo);
 671                                 goto skip;
 672                         case CH_QUIT:
 673                                 /* Set the quit/interrupted flags. */
 674 lquit:                          quit = 1;
 675                                 F_SET(sp->gp, G_INTERRUPTED);
 676
 677                                 /*
 678                                  * Resolve any changes, then return to (and
 679                                  * exit from) the main loop.
 680                                  */
 681                                 goto endmatch;
 682                         }
 683                 }
 684
 685                 /*
 686                  * Set the cursor to the last position changed, converting
 687                  * from 1-based to 0-based.
 688                  */
 689                 sp->lno = lno;
 690                 sp->cno = match[0].rm_so;
 691
 692                 /* Copy the bytes before the match into the build buffer. */
 693                 BUILD(sp, st + offset, match[0].rm_so);
 694
 695                 /* Substitute the matching bytes. */
 696                 didsub = 1;
 697                 if (re_sub(sp, st + offset, &lb, &lbclen, &lblen, match))
 698                         goto err;
 699
 700                 /* Set the change flag so we know this line was modified. */
 701                 linechanged = 1;
 702
 703                 /* Move past the matched bytes. */
 704 skip:           offset += match[0].rm_eo;
 705                 len -= match[0].rm_eo;
 706
 707                 /* A match cannot be followed by an empty pattern. */
 708                 empty_ok = 0;
 709
 710                 /*
 711                  * If doing a global change with confirmation, we have to
 712                  * update the screen.  The basic idea is to store the line
 713                  * so the screen update routines can find it, and restart.
 714                  */
 715                 if (didsub && sp->c_suffix && sp->g_suffix) {
 716                         /*
 717                          * The new search offset will be the end of the
 718                          * modified line.
 719                          */
 720                         saved_offset = lbclen;
 721
 722                         /* Copy the rest of the line. */
 723                         if (len)
 724                                 BUILD(sp, st + offset, len)
 725
 726                         /* Set the new offset. */
 727                         offset = saved_offset;
 728
 729                         /* Store inserted lines, adjusting the build buffer. */
 730                         last = 0;
 731                         if (sp->newl_cnt) {
 732                                 for (cnt = 0;
 733                                     cnt < sp->newl_cnt; ++cnt, ++lno, ++elno) {
 734                                         if (db_insert(sp, lno,
 735                                             lb + last, sp->newl[cnt] - last))
 736                                                 goto err;
 737                                         last = sp->newl[cnt] + 1;
 738                                         ++sp->rptlines[L_ADDED];
 739                                 }
 740                                 lbclen -= last;
 741                                 offset -= last;
 742                                 sp->newl_cnt = 0;
 743                         }
 744
 745                         /* Store and retrieve the line. */
 746                         if (db_set(sp, lno, lb + last, lbclen))
 747                                 goto err;
 748                         if (db_get(sp, lno, DBG_FATAL, &st, &llen))
 749                                 goto err;
 750                         ADD_SPACE_RETW(sp, bp, blen, llen)
 751                         MEMCPYW(bp, st, llen);
 752                         st = bp;
 753                         len = llen - offset;
 754
 755                         /* Restart the build. */
 756                         lbclen = 0;
 757                         BUILD(sp, st, offset);
 758
 759                         /*
 760                          * If we haven't already done the after-the-string
 761                          * match, do one.  Set REG_NOTEOL so the '$' pattern
 762                          * only matches once.
 763                          */
 764                         if (!do_eol_match)
 765                                 goto endmatch;
 766                         if (offset == len) {
 767                                 do_eol_match = 0;
 768                                 eflags |= REG_NOTEOL;
 769                         }
 770                         goto nextmatch;
 771                 }
 772
 773                 /*
 774                  * If it's a global:
 775                  *
 776                  * If at the end of the string, do a test for the after
 777                  * the string match.  Set REG_NOTEOL so the '$' pattern
 778                  * only matches once.
 779                  */
 780                 if (sp->g_suffix && do_eol_match) {
 781                         if (len == 0) {
 782                                 do_eol_match = 0;
 783                                 eflags |= REG_NOTEOL;
 784                         }
 785                         goto nextmatch;
 786                 }
 787
 788 endmatch:       if (!linechanged)
 789                         continue;
 790
 791                 /* Copy any remaining bytes into the build buffer. */
 792                 if (len)
 793                         BUILD(sp, st + offset, len)
 794
 795                 /* Store inserted lines, adjusting the build buffer. */
 796                 last = 0;
 797                 if (sp->newl_cnt) {
 798                         for (cnt = 0;
 799                             cnt < sp->newl_cnt; ++cnt, ++lno, ++elno) {
 800                                 if (db_insert(sp,
 801                                     lno, lb + last, sp->newl[cnt] - last))
 802                                         goto err;
 803                                 last = sp->newl[cnt] + 1;
 804                                 ++sp->rptlines[L_ADDED];
 805                         }
 806                         lbclen -= last;
 807                         sp->newl_cnt = 0;
 808                 }
 809
 810                 /* Store the changed line. */
 811                 if (db_set(sp, lno, lb + last, lbclen))
 812                         goto err;
 813
 814                 /* Update changed line counter. */
 815                 if (sp->rptlchange != lno) {
 816                         sp->rptlchange = lno;
 817                         ++sp->rptlines[L_CHANGED];
 818                 }
 819
 820                 /*
 821                  * !!!
 822                  * Display as necessary.  Historic practice is to only
 823                  * display the last line of a line split into multiple
 824                  * lines.
 825                  */
 826                 if (lflag || nflag || pflag) {
 827                         from.lno = to.lno = lno;
 828                         from.cno = to.cno = 0;
 829                         if (lflag)
 830                                 (void)ex_print(sp, cmdp, &from, &to, E_C_LIST);
 831                         if (nflag)
 832                                 (void)ex_print(sp, cmdp, &from, &to, E_C_HASH);
 833                         if (pflag)
 834                                 (void)ex_print(sp, cmdp, &from, &to, E_C_PRINT);
 835                 }
 836         }
 837
 838         /*
 839          * !!!
 840          * Historically, vi attempted to leave the cursor at the same place if
 841          * the substitution was done at the current cursor position.  Otherwise
 842          * it moved it to the first non-blank of the last line changed.  There
 843          * were some problems: for example, :s/$/foo/ with the cursor on the
 844          * last character of the line left the cursor on the last character, or
 845          * the & command with multiple occurrences of the matching string in the
 846          * line usually left the cursor in a fairly random position.
 847          *
 848          * We try to do the same thing, with the exception that if the user is
 849          * doing substitution with confirmation, we move to the last line about
 850          * which the user was consulted, as opposed to the last line that they
 851          * actually changed.  This prevents a screen flash if the user doesn't
 852          * change many of the possible lines.
 853          */
 854         if (!sp->c_suffix && (sp->lno != slno || sp->cno != scno)) {
 855                 sp->cno = 0;
 856                 (void)nonblank(sp, sp->lno, &sp->cno);
 857         }
 858
 859         /*
 860          * If not in a global command, and nothing matched, say so.
 861          * Else, if none of the lines displayed, put something up.
 862          */
 863         rval = 0;
 864         if (!matched) {
 865                 if (!F_ISSET(sp, SC_EX_GLOBAL)) {
 866                         msgq(sp, M_ERR, "157|No match found");
 867                         goto err;
 868                 }
 869         } else if (!lflag && !nflag && !pflag)
 870                 F_SET(cmdp, E_AUTOPRINT);
 871
 872         if (0) {
 873 err:            rval = 1;
 874         }
 875
 876         if (bp != NULL)
 877                 FREE_SPACEW(sp, bp, blen);
 878         if (lb != NULL)
 879                 free(lb);
 880         return (rval);
 881 }
 882
 883 /*
 884  * re_compile --
 885  *      Compile the RE.
 886  *
 887  * PUBLIC: int re_compile __P((SCR *,
 888  * PUBLIC:     CHAR_T *, size_t, CHAR_T **, size_t *, regex_t *, u_int));
 889  */
 890 int
 891 re_compile(SCR *sp, CHAR_T *ptrn, size_t plen, CHAR_T **ptrnp, size_t *lenp, regex_t *rep, u_int flags)
 892 {
 893         size_t len;
 894         int reflags, replaced, rval;
 895         CHAR_T *p;
 896
 897         /* Set RE flags. */
 898         reflags = 0;
 899         if (LF_ISSET(SEARCH_EXTEND))
 900                 reflags |= REG_EXTENDED;
 901         if (LF_ISSET(SEARCH_IC))
 902                 reflags |= REG_ICASE;
 903         if (LF_ISSET(SEARCH_LITERAL))
 904                 reflags |= REG_NOSPEC;
 905         if (!LF_ISSET(SEARCH_NOOPT | SEARCH_CSCOPE | SEARCH_TAG)) {
 906                 if (O_ISSET(sp, O_EXTENDED))
 907                         reflags |= REG_EXTENDED;
 908                 if (O_ISSET(sp, O_IGNORECASE))
 909                         reflags |= REG_ICASE;
 910                 if (O_ISSET(sp, O_ICLOWER))
 911                         goto iclower;
 912         }
 913         if (LF_ISSET(SEARCH_ICL)) {
 914 iclower:        for (p = ptrn, len = plen; len > 0; ++p, --len)
 915                         if (ISUPPER(*p))
 916                                 break;
 917                 if (len == 0)
 918                         reflags |= REG_ICASE;
 919         }
 920
 921         /* If we're replacing a saved value, clear the old one. */
 922         if (LF_ISSET(SEARCH_CSEARCH) && F_ISSET(sp, SC_RE_SEARCH)) {
 923                 regfree(&sp->re_c);
 924                 F_CLR(sp, SC_RE_SEARCH);
 925         }
 926         if (LF_ISSET(SEARCH_CSUBST) && F_ISSET(sp, SC_RE_SUBST)) {
 927                 regfree(&sp->subre_c);
 928                 F_CLR(sp, SC_RE_SUBST);
 929         }
 930
 931         /*
 932          * If we're saving the string, it's a pattern we haven't seen before,
 933          * so convert the vi-style RE's to POSIX 1003.2 RE's.  Save a copy for
 934          * later recompilation.   Free any previously saved value.
 935          */
 936         if (ptrnp != NULL) {
 937                 replaced = 0;
 938                 if (LF_ISSET(SEARCH_CSCOPE)) {
 939                         if (re_cscope_conv(sp, &ptrn, &plen, &replaced))
 940                                 return (1);
 941                         /*
 942                          * XXX
 943                          * Currently, the match-any-<blank> expression used in
 944                          * re_cscope_conv() requires extended RE's.  This may
 945                          * not be right or safe.
 946                          */
 947                         reflags |= REG_EXTENDED;
 948                 } else if (LF_ISSET(SEARCH_TAG)) {
 949                         if (re_tag_conv(sp, &ptrn, &plen, &replaced))
 950                                 return (1);
 951                 } else if (!LF_ISSET(SEARCH_LITERAL))
 952                         if (re_conv(sp, &ptrn, &plen, &replaced))
 953                                 return (1);
 954
 955                 /* Discard previous pattern. */
 956                 if (*ptrnp != NULL) {
 957                         free(*ptrnp);
 958                         *ptrnp = NULL;
 959                 }
 960                 if (lenp != NULL)
 961                         *lenp = plen;
 962
 963                 /*
 964                  * Copy the string into allocated memory.
 965                  *
 966                  * XXX
 967                  * Regcomp isn't 8-bit clean, so the pattern is nul-terminated
 968                  * for now.  There's just no other solution.
 969                  */
 970                 MALLOC(sp, *ptrnp, CHAR_T *, (plen + 1) * sizeof(CHAR_T));
 971                 if (*ptrnp != NULL) {
 972                         MEMCPYW(*ptrnp, ptrn, plen);
 973                         (*ptrnp)[plen] = '\0';
 974                 }
 975
 976                 /* Free up conversion-routine-allocated memory. */
 977                 if (replaced)
 978                         FREE_SPACEW(sp, ptrn, 0);
 979
 980                 if (*ptrnp == NULL)
 981                         return (1);
 982
 983                 ptrn = *ptrnp;
 984         }
 985
 986         /*
 987          * XXX
 988          * Regcomp isn't 8-bit clean, so we just lost if the pattern
 989          * contained a nul.  Bummer!
 990          */
 991         if ((rval = regcomp(rep, ptrn, /* plen, */ reflags)) != 0) {
 992                 if (LF_ISSET(SEARCH_MSG))
 993                         re_error(sp, rval, rep);
 994                 return (1);
 995         }
 996
 997         if (LF_ISSET(SEARCH_CSEARCH))
 998                 F_SET(sp, SC_RE_SEARCH);
 999         if (LF_ISSET(SEARCH_CSUBST))
1000                 F_SET(sp, SC_RE_SUBST);
1001
1002         return (0);
1003 }
1004
1005 /*
1006  * re_conv --
1007  *      Convert vi's regular expressions into something that the
1008  *      the POSIX 1003.2 RE functions can handle.
1009  *
1010  * There are three conversions we make to make vi's RE's (specifically
1011  * the global, search, and substitute patterns) work with POSIX RE's.
1012  *
1013  * 1: If O_MAGIC is not set, strip backslashes from the magic character
1014  *    set (.[*~) that have them, and add them to the ones that don't.
1015  * 2: If O_MAGIC is not set, the string "\~" is replaced with the text
1016  *    from the last substitute command's replacement string.  If O_MAGIC
1017  *    is set, it's the string "~".
1018  * 3: The pattern \<ptrn\> does "word" searches, convert it to use the
1019  *    new RE escapes.
1020  *
1021  * !!!/XXX
1022  * This doesn't exactly match the historic behavior of vi because we do
1023  * the ~ substitution before calling the RE engine, so magic characters
1024  * in the replacement string will be expanded by the RE engine, and they
1025  * weren't historically.  It's a bug.
1026  */
1027 static int
1028 re_conv(SCR *sp, CHAR_T **ptrnp, size_t *plenp, int *replacedp)
1029 {
1030         size_t blen, len, needlen;
1031         int magic;
1032         CHAR_T *bp, *p, *t;
1033
1034         /*
1035          * First pass through, we figure out how much space we'll need.
1036          * We do it in two passes, on the grounds that most of the time
1037          * the user is doing a search and won't have magic characters.
1038          * That way we can skip most of the memory allocation and copies.
1039          */
1040         magic = 0;
1041         for (p = *ptrnp, len = *plenp, needlen = 0; len > 0; ++p, --len)
1042                 switch (*p) {
1043                 case '\\':
1044                         if (len > 1) {
1045                                 --len;
1046                                 switch (*++p) {
1047                                 case '<':
1048                                         magic = 1;
1049                                         needlen += RE_WSTART_LEN + 1;
1050                                         break;
1051                                 case '>':
1052                                         magic = 1;
1053                                         needlen += RE_WSTOP_LEN + 1;
1054                                         break;
1055                                 case '~':
1056                                         if (!O_ISSET(sp, O_MAGIC)) {
1057                                                 magic = 1;
1058                                                 needlen += sp->repl_len;
1059                                         }
1060                                         break;
1061                                 case '.':
1062                                 case '[':
1063                                 case '*':
1064                                         if (!O_ISSET(sp, O_MAGIC)) {
1065                                                 magic = 1;
1066                                                 needlen += 1;
1067                                         }
1068                                         break;
1069                                 default:
1070                                         needlen += 2;
1071                                 }
1072                         } else
1073                                 needlen += 1;
1074                         break;
1075                 case '~':
1076                         if (O_ISSET(sp, O_MAGIC)) {
1077                                 magic = 1;
1078                                 needlen += sp->repl_len;
1079                         }
1080                         break;
1081                 case '.':
1082                 case '[':
1083                 case '*':
1084                         if (!O_ISSET(sp, O_MAGIC)) {
1085                                 magic = 1;
1086                                 needlen += 2;
1087                         }
1088                         break;
1089                 default:
1090                         needlen += 1;
1091                         break;
1092                 }
1093
1094         if (!magic) {
1095                 *replacedp = 0;
1096                 return (0);
1097         }
1098
1099         /* Get enough memory to hold the final pattern. */
1100         *replacedp = 1;
1101         GET_SPACE_RETW(sp, bp, blen, needlen);
1102
1103         for (p = *ptrnp, len = *plenp, t = bp; len > 0; ++p, --len)
1104                 switch (*p) {
1105                 case '\\':
1106                         if (len > 1) {
1107                                 --len;
1108                                 switch (*++p) {
1109                                 case '<':
1110                                         MEMCPY(t,
1111                                             RE_WSTART, RE_WSTART_LEN);
1112                                         t += RE_WSTART_LEN;
1113                                         break;
1114                                 case '>':
1115                                         MEMCPY(t,
1116                                             RE_WSTOP, RE_WSTOP_LEN);
1117                                         t += RE_WSTOP_LEN;
1118                                         break;
1119                                 case '~':
1120                                         if (O_ISSET(sp, O_MAGIC))
1121                                                 *t++ = '~';
1122                                         else {
1123                                                 MEMCPYW(t,
1124                                                     sp->repl, sp->repl_len);
1125                                                 t += sp->repl_len;
1126                                         }
1127                                         break;
1128                                 case '.':
1129                                 case '[':
1130                                 case '*':
1131                                         if (O_ISSET(sp, O_MAGIC))
1132                                                 *t++ = '\\';
1133                                         *t++ = *p;
1134                                         break;
1135                                 default:
1136                                         *t++ = '\\';
1137                                         *t++ = *p;
1138                                 }
1139                         } else
1140                                 *t++ = '\\';
1141                         break;
1142                 case '~':
1143                         if (O_ISSET(sp, O_MAGIC)) {
1144                                 MEMCPYW(t, sp->repl, sp->repl_len);
1145                                 t += sp->repl_len;
1146                         } else
1147                                 *t++ = '~';
1148                         break;
1149                 case '.':
1150                 case '[':
1151                 case '*':
1152                         if (!O_ISSET(sp, O_MAGIC))
1153                                 *t++ = '\\';
1154                         *t++ = *p;
1155                         break;
1156                 default:
1157                         *t++ = *p;
1158                         break;
1159                 }
1160
1161         *ptrnp = bp;
1162         *plenp = t - bp;
1163         return (0);
1164 }
1165
1166 /*
1167  * re_tag_conv --
1168  *      Convert a tags search path into something that the POSIX
1169  *      1003.2 RE functions can handle.
1170  */
1171 static int
1172 re_tag_conv(SCR *sp, CHAR_T **ptrnp, size_t *plenp, int *replacedp)
1173 {
1174         size_t blen, len;
1175         int lastdollar;
1176         CHAR_T *bp, *p, *t;
1177
1178         len = *plenp;
1179
1180         /* Max memory usage is 2 times the length of the string. */
1181         *replacedp = 1;
1182         GET_SPACE_RETW(sp, bp, blen, len * 2);
1183
1184         p = *ptrnp;
1185         t = bp;
1186
1187         /* If the last character is a '/' or '?', we just strip it. */
1188         if (len > 0 && (p[len - 1] == '/' || p[len - 1] == '?'))
1189                 --len;
1190
1191         /* If the next-to-last or last character is a '$', it's magic. */
1192         if (len > 0 && p[len - 1] == '$') {
1193                 --len;
1194                 lastdollar = 1;
1195         } else
1196                 lastdollar = 0;
1197
1198         /* If the first character is a '/' or '?', we just strip it. */
1199         if (len > 0 && (p[0] == '/' || p[0] == '?')) {
1200                 ++p;
1201                 --len;
1202         }
1203
1204         /* If the first or second character is a '^', it's magic. */
1205         if (p[0] == '^') {
1206                 *t++ = *p++;
1207                 --len;
1208         }
1209
1210         /*
1211          * Escape every other magic character we can find, meanwhile stripping
1212          * the backslashes ctags inserts when escaping the search delimiter
1213          * characters.
1214          */
1215         for (; len > 0; --len) {
1216                 if (p[0] == '\\' && (p[1] == '/' || p[1] == '?')) {
1217                         ++p;
1218                         --len;
1219                 } else if (strchr("^.[]$*", p[0]))
1220                         *t++ = '\\';
1221                 *t++ = *p++;
1222         }
1223         if (lastdollar)
1224                 *t++ = '$';
1225
1226         *ptrnp = bp;
1227         *plenp = t - bp;
1228         return (0);
1229 }
1230
1231 /*
1232  * re_cscope_conv --
1233  *       Convert a cscope search path into something that the POSIX
1234  *      1003.2 RE functions can handle.
1235  */
1236 static int
1237 re_cscope_conv(SCR *sp, CHAR_T **ptrnp, size_t *plenp, int *replacedp)
1238 {
1239         size_t blen, len, nspaces;
1240         CHAR_T *bp, *t;
1241         CHAR_T *p;
1242         const CHAR_T *wp;
1243         size_t wlen;
1244
1245         /*
1246          * Each space in the source line printed by cscope represents an
1247          * arbitrary sequence of spaces, tabs, and comments.
1248          */
1249 #define CSCOPE_RE_SPACE         "([ \t]|/\\*([^*]|\\*/)*\\*/)*"
1250 #define CSCOPE_LEN      sizeof(CSCOPE_RE_SPACE) - 1
1251         CHAR2INT(sp, CSCOPE_RE_SPACE, CSCOPE_LEN, wp, wlen);
1252         for (nspaces = 0, p = *ptrnp, len = *plenp; len > 0; ++p, --len)
1253                 if (*p == ' ')
1254                         ++nspaces;
1255
1256         /*
1257          * Allocate plenty of space:
1258          *      the string, plus potential escaping characters;
1259          *      nspaces + 2 copies of CSCOPE_RE_SPACE;
1260          *      ^, $, nul terminator characters.
1261          */
1262         *replacedp = 1;
1263         len = (p - *ptrnp) * 2 + (nspaces + 2) * sizeof(CSCOPE_RE_SPACE) + 3;
1264         GET_SPACE_RETW(sp, bp, blen, len);
1265
1266         p = *ptrnp;
1267         t = bp;
1268
1269         *t++ = '^';
1270         MEMCPYW(t, wp, wlen);
1271         t += wlen;
1272
1273         for (len = *plenp; len > 0; ++p, --len)
1274                 if (*p == ' ') {
1275                         MEMCPYW(t, wp, wlen);
1276                         t += wlen;
1277                 } else {
1278                         if (strchr("\\^.[]$*+?()|{}", *p))
1279                                 *t++ = '\\';
1280                         *t++ = *p;
1281                 }
1282
1283         MEMCPYW(t, wp, wlen);
1284         t += wlen;
1285         *t++ = '$';
1286
1287         *ptrnp = bp;
1288         *plenp = t - bp;
1289         return (0);
1290 }
1291
1292 /*
1293  * re_error --
1294  *      Report a regular expression error.
1295  *
1296  * PUBLIC: void re_error __P((SCR *, int, regex_t *));
1297  */
1298 void
1299 re_error(SCR *sp, int errcode, regex_t *preg)
1300 {
1301         size_t sz;
1302         char *oe;
1303
1304         sz = regerror(errcode, preg, NULL, 0);
1305         if ((oe = malloc(sz)) == NULL)
1306                 msgq(sp, M_SYSERR, NULL);
1307         else {
1308                 (void)regerror(errcode, preg, oe, sz);
1309                 msgq(sp, M_ERR, "RE error: %s", oe);
1310                 free(oe);
1311         }
1312 }
1313
1314 /*
1315  * re_sub --
1316  *      Do the substitution for a regular expression.
1317  */
1318 static int
1319 re_sub(SCR *sp, CHAR_T *ip, CHAR_T **lbp, size_t *lbclenp, size_t *lblenp, regmatch_t *match)
1320
1321                                         /* Input line. */
1322
1323
1324
1325 {
1326         enum { C_NOT_SET, C_LOWER, C_ONE_LOWER, C_ONE_UPPER, C_UPPER } conv;
1327         size_t lbclen, lblen;           /* Local copies. */
1328         size_t mlen;                    /* Match length. */
1329         size_t rpl;                     /* Remaining replacement length. */
1330         CHAR_T *rp;                     /* Replacement pointer. */
1331         int ch;
1332         int no;                         /* Match replacement offset. */
1333         CHAR_T *p, *t;                  /* Buffer pointers. */
1334         CHAR_T *lb;                     /* Local copies. */
1335
1336         lb = *lbp;                      /* Get local copies. */
1337         lbclen = *lbclenp;
1338         lblen = *lblenp;
1339
1340         /*
1341          * QUOTING NOTE:
1342          *
1343          * There are some special sequences that vi provides in the
1344          * replacement patterns.
1345          *       & string the RE matched (\& if nomagic set)
1346          *      \# n-th regular subexpression
1347          *      \E end \U, \L conversion
1348          *      \e end \U, \L conversion
1349          *      \l convert the next character to lower-case
1350          *      \L convert to lower-case, until \E, \e, or end of replacement
1351          *      \u convert the next character to upper-case
1352          *      \U convert to upper-case, until \E, \e, or end of replacement
1353          *
1354          * Otherwise, since this is the lowest level of replacement, discard
1355          * all escaping characters.  This (hopefully) matches historic practice.
1356          */
1357 #define OUTCH(ch, nltrans) {                                            \
1358         CHAR_T __ch = (ch);                                             \
1359         u_int __value = KEY_VAL(sp, __ch);                              \
1360         if (nltrans && (__value == K_CR || __value == K_NL)) {          \
1361                 NEEDNEWLINE(sp);                                        \
1362                 sp->newl[sp->newl_cnt++] = lbclen;                      \
1363         } else if (conv != C_NOT_SET) {                                 \
1364                 switch (conv) {                                         \
1365                 case C_ONE_LOWER:                                       \
1366                         conv = C_NOT_SET;                               \
1367                         /* FALLTHROUGH */                               \
1368                 case C_LOWER:                                           \
1369                         if (ISUPPER(__ch))                              \
1370                                 __ch = TOLOWER(__ch);                   \
1371                         break;                                          \
1372                 case C_ONE_UPPER:                                       \
1373                         conv = C_NOT_SET;                               \
1374                         /* FALLTHROUGH */                               \
1375                 case C_UPPER:                                           \
1376                         if (ISLOWER(__ch))                              \
1377                                 __ch = TOUPPER(__ch);                   \
1378                         break;                                          \
1379                 default:                                                \
1380                         abort();                                        \
1381                 }                                                       \
1382         }                                                               \
1383         NEEDSP(sp, 1, p);                                               \
1384         *p++ = __ch;                                                    \
1385         ++lbclen;                                                       \
1386 }
1387         conv = C_NOT_SET;
1388         for (rp = sp->repl, rpl = sp->repl_len, p = lb + lbclen; rpl--;) {
1389                 switch (ch = *rp++) {
1390                 case '&':
1391                         if (O_ISSET(sp, O_MAGIC)) {
1392                                 no = 0;
1393                                 goto subzero;
1394                         }
1395                         break;
1396                 case '\\':
1397                         if (rpl == 0)
1398                                 break;
1399                         --rpl;
1400                         switch (ch = *rp) {
1401                         case '&':
1402                                 ++rp;
1403                                 if (!O_ISSET(sp, O_MAGIC)) {
1404                                         no = 0;
1405                                         goto subzero;
1406                                 }
1407                                 break;
1408                         case '0': case '1': case '2': case '3': case '4':
1409                         case '5': case '6': case '7': case '8': case '9':
1410                                 no = *rp++ - '0';
1411 subzero:                        if (match[no].rm_so == -1 ||
1412                                     match[no].rm_eo == -1)
1413                                         break;
1414                                 mlen = match[no].rm_eo - match[no].rm_so;
1415                                 for (t = ip + match[no].rm_so; mlen--; ++t)
1416                                         OUTCH(*t, 0);
1417                                 continue;
1418                         case 'e':
1419                         case 'E':
1420                                 ++rp;
1421                                 conv = C_NOT_SET;
1422                                 continue;
1423                         case 'l':
1424                                 ++rp;
1425                                 conv = C_ONE_LOWER;
1426                                 continue;
1427                         case 'L':
1428                                 ++rp;
1429                                 conv = C_LOWER;
1430                                 continue;
1431                         case 'u':
1432                                 ++rp;
1433                                 conv = C_ONE_UPPER;
1434                                 continue;
1435                         case 'U':
1436                                 ++rp;
1437                                 conv = C_UPPER;
1438                                 continue;
1439                         default:
1440                                 ++rp;
1441                                 break;
1442                         }
1443                 }
1444                 OUTCH(ch, 1);
1445         }
1446
1447         *lbp = lb;                      /* Update caller's information. */
1448         *lbclenp = lbclen;
1449         *lblenp = lblen;
1450         return (0);
1451 }