ex/ex_subst.c

   1 /*-
   2  * Copyright (c) 1992, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  * Copyright (c) 1992, 1993, 1994, 1995, 1996
   5  *      Keith Bostic.  All rights reserved.
   6  *
   7  * See the LICENSE file for redistribution information.
   8  */
   9
  10 #include "config.h"
  11
  12 #ifndef lint
  13 static const char sccsid[] = "$Id: ex_subst.c,v 10.40 1997/01/13 18:27:54 bostic Exp $ (Berkeley) $Date: 1997/01/13 18:27:54 $";
  14 #endif /* not lint */
  15
  16 #include <sys/types.h>
  17 #include <sys/queue.h>
  18 #include <sys/time.h>
  19
  20 #include <bitstring.h>
  21 #include <ctype.h>
  22 #include <errno.h>
  23 #include <limits.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <unistd.h>
  28
  29 #include "../common/common.h"
  30 #include "../vi/vi.h"
  31
  32 #define SUB_FIRST       0x01            /* The 'r' flag isn't reasonable. */
  33 #define SUB_MUSTSETR    0x02            /* The 'r' flag is required. */
  34
  35 static int re_conv __P((SCR *, char **, size_t *, int *));
  36 static int re_cscope_conv __P((SCR *, char **, size_t *, int *));
  37 static int re_sub __P((SCR *,
  38                 char *, char **, size_t *, size_t *, regmatch_t [10]));
  39 static int re_tag_conv __P((SCR *, char **, size_t *, int *));
  40 static int s __P((SCR *, EXCMD *, char *, regex_t *, u_int));
  41
  42 /*
  43  * ex_s --
  44  *      [line [,line]] s[ubstitute] [[/;]pat[/;]/repl[/;] [cgr] [count] [#lp]]
  45  *
  46  *      Substitute on lines matching a pattern.
  47  *
  48  * PUBLIC: int ex_s __P((SCR *, EXCMD *));
  49  */
  50 int
  51 ex_s(sp, cmdp)
  52         SCR *sp;
  53         EXCMD *cmdp;
  54 {
  55         regex_t *re;
  56         size_t blen, len;
  57         u_int flags;
  58         int delim;
  59         char *bp, *ptrn, *rep, *p, *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                 *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] == '\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] == '%' && (p[1] == '\0' || p[1] == delim))
 200                 p += p[1] == delim ? 2 : 1;
 201         else {
 202                 for (rep = p, len = 0;
 203                     p[0] != '\0' && p[0] != delim; ++p, ++len)
 204                         if (p[0] == '~')
 205                                 len += sp->repl_len;
 206                 GET_SPACE_RET(sp, bp, blen, len);
 207                 for (t = bp, len = 0, p = rep;;) {
 208                         if (p[0] == '\0' || p[0] == delim) {
 209                                 if (p[0] == delim)
 210                                         ++p;
 211                                 break;
 212                         }
 213                         if (p[0] == '\\') {
 214                                 if (p[1] == delim)
 215                                         ++p;
 216                                 else if (p[1] == '\\') {
 217                                         *t++ = *p++;
 218                                         ++len;
 219                                 } else if (p[1] == '~') {
 220                                         ++p;
 221                                         if (!O_ISSET(sp, O_MAGIC))
 222                                                 goto tilde;
 223                                 }
 224                         } else if (p[0] == '~' && O_ISSET(sp, O_MAGIC)) {
 225 tilde:                          ++p;
 226                                 memcpy(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)) == NULL) {
 238                                 msgq(sp, M_SYSERR, NULL);
 239                                 FREE_SPACE(sp, bp, blen);
 240                                 return (1);
 241                         }
 242                         memcpy(sp->repl, bp, len);
 243                 }
 244                 FREE_SPACE(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(sp, cmdp)
 259         SCR *sp;
 260         EXCMD *cmdp;
 261 {
 262         if (sp->subre == NULL) {
 263                 ex_emsg(sp, NULL, EXM_NOPREVRE);
 264                 return (1);
 265         }
 266         if (!F_ISSET(sp, SC_RE_SUBST) &&
 267             re_compile(sp, sp->subre, sp->subre_len,
 268             NULL, NULL, &sp->subre_c, SEARCH_CSUBST | SEARCH_MSG))
 269                 return (1);
 270         return (s(sp,
 271             cmdp, cmdp->argc ? cmdp->argv[0]->bp : NULL, &sp->subre_c, 0));
 272 }
 273
 274 /*
 275  * ex_subtilde --
 276  *      [line [,line]] ~ [cgr] [count] [#lp]]
 277  *
 278  *      Substitute using the last RE and last substitute replacement pattern.
 279  *
 280  * PUBLIC: int ex_subtilde __P((SCR *, EXCMD *));
 281  */
 282 int
 283 ex_subtilde(sp, cmdp)
 284         SCR *sp;
 285         EXCMD *cmdp;
 286 {
 287         if (sp->re == NULL) {
 288                 ex_emsg(sp, NULL, EXM_NOPREVRE);
 289                 return (1);
 290         }
 291         if (!F_ISSET(sp, SC_RE_SEARCH) && re_compile(sp, sp->re,
 292             sp->re_len, NULL, NULL, &sp->re_c, SEARCH_CSEARCH | SEARCH_MSG))
 293                 return (1);
 294         return (s(sp,
 295             cmdp, cmdp->argc ? cmdp->argv[0]->bp : NULL, &sp->re_c, 0));
 296 }
 297
 298 /*
 299  * s --
 300  * Do the substitution.  This stuff is *really* tricky.  There are lots of
 301  * special cases, and general nastiness.  Don't mess with it unless you're
 302  * pretty confident.
 303  *
 304  * The nasty part of the substitution is what happens when the replacement
 305  * string contains newlines.  It's a bit tricky -- consider the information
 306  * that has to be retained for "s/f\(o\)o/^M\1^M\1/".  The solution here is
 307  * to build a set of newline offsets which we use to break the line up later,
 308  * when the replacement is done.  Don't change it unless you're *damned*
 309  * confident.
 310  */
 311 #define NEEDNEWLINE(sp) {                                               \
 312         if (sp->newl_len == sp->newl_cnt) {                             \
 313                 sp->newl_len += 25;                                     \
 314                 REALLOC(sp, sp->newl, size_t *,                         \
 315                     sp->newl_len * sizeof(size_t));                     \
 316                 if (sp->newl == NULL) {                                 \
 317                         sp->newl_len = 0;                               \
 318                         return (1);                                     \
 319                 }                                                       \
 320         }                                                               \
 321 }
 322
 323 #define BUILD(sp, l, len) {                                             \
 324         if (lbclen + (len) > lblen) {                                   \
 325                 lblen += MAX(lbclen + (len), 256);                      \
 326                 REALLOC(sp, lb, char *, lblen);                         \
 327                 if (lb == NULL) {                                       \
 328                         lbclen = 0;                                     \
 329                         return (1);                                     \
 330                 }                                                       \
 331         }                                                               \
 332         memcpy(lb + lbclen, l, len);                                    \
 333         lbclen += len;                                                  \
 334 }
 335
 336 #define NEEDSP(sp, len, pnt) {                                          \
 337         if (lbclen + (len) > lblen) {                                   \
 338                 lblen += MAX(lbclen + (len), 256);                      \
 339                 REALLOC(sp, lb, char *, lblen);                         \
 340                 if (lb == NULL) {                                       \
 341                         lbclen = 0;                                     \
 342                         return (1);                                     \
 343                 }                                                       \
 344                 pnt = lb + lbclen;                                      \
 345         }                                                               \
 346 }
 347
 348 static int
 349 s(sp, cmdp, s, re, flags)
 350         SCR *sp;
 351         EXCMD *cmdp;
 352         char *s;
 353         regex_t *re;
 354         u_int flags;
 355 {
 356         EVENT ev;
 357         MARK from, to;
 358         TEXTH tiq;
 359         recno_t elno, lno, slno;
 360         regmatch_t match[10];
 361         size_t blen, cnt, last, lbclen, lblen, len, llen;
 362         size_t offset, saved_offset, scno;
 363         int cflag, lflag, nflag, pflag, rflag;
 364         int didsub, do_eol_match, eflags, empty_ok, eval;
 365         int linechanged, matched, quit, rval;
 366         char *bp, *lb;
 367
 368         NEEDFILE(sp, cmdp);
 369
 370         slno = sp->lno;
 371         scno = sp->cno;
 372
 373         /*
 374          * !!!
 375          * Historically, the 'g' and 'c' suffices were always toggled as flags,
 376          * so ":s/A/B/" was the same as ":s/A/B/ccgg".  If O_EDCOMPATIBLE was
 377          * not set, they were initialized to 0 for all substitute commands.  If
 378          * O_EDCOMPATIBLE was set, they were initialized to 0 only if the user
 379          * specified substitute/replacement patterns (see ex_s()).
 380          */
 381         if (!O_ISSET(sp, O_EDCOMPATIBLE))
 382                 sp->c_suffix = sp->g_suffix = 0;
 383
 384         /*
 385          * Historic vi permitted the '#', 'l' and 'p' options in vi mode, but
 386          * it only displayed the last change.  I'd disallow them, but they are
 387          * useful in combination with the [v]global commands.  In the current
 388          * model the problem is combining them with the 'c' flag -- the screen
 389          * would have to flip back and forth between the confirm screen and the
 390          * ex print screen, which would be pretty awful.  We do display all
 391          * changes, though, for what that's worth.
 392          *
 393          * !!!
 394          * Historic vi was fairly strict about the order of "options", the
 395          * count, and "flags".  I'm somewhat fuzzy on the difference between
 396          * options and flags, anyway, so this is a simpler approach, and we
 397          * just take it them in whatever order the user gives them.  (The ex
 398          * usage statement doesn't reflect this.)
 399          */
 400         cflag = lflag = nflag = pflag = rflag = 0;
 401         if (s == NULL)
 402                 goto noargs;
 403         for (lno = OOBLNO; *s != '\0'; ++s)
 404                 switch (*s) {
 405                 case ' ':
 406                 case '\t':
 407                         continue;
 408                 case '+':
 409                         ++cmdp->flagoff;
 410                         break;
 411                 case '-':
 412                         --cmdp->flagoff;
 413                         break;
 414                 case '0': case '1': case '2': case '3': case '4':
 415                 case '5': case '6': case '7': case '8': case '9':
 416                         if (lno != OOBLNO)
 417                                 goto usage;
 418                         errno = 0;
 419                         lno = strtoul(s, &s, 10);
 420                         if (*s == '\0')         /* Loop increment correction. */
 421                                 --s;
 422                         if (errno == ERANGE) {
 423                                 if (lno == LONG_MAX)
 424                                         msgq(sp, M_ERR, "153|Count overflow");
 425                                 else if (lno == LONG_MIN)
 426                                         msgq(sp, M_ERR, "154|Count underflow");
 427                                 else
 428                                         msgq(sp, M_SYSERR, NULL);
 429                                 return (1);
 430                         }
 431                         /*
 432                          * In historic vi, the count was inclusive from the
 433                          * second address.
 434                          */
 435                         cmdp->addr1.lno = cmdp->addr2.lno;
 436                         cmdp->addr2.lno += lno - 1;
 437                         if (!db_exist(sp, cmdp->addr2.lno) &&
 438                             db_last(sp, &cmdp->addr2.lno))
 439                                 return (1);
 440                         break;
 441                 case '#':
 442                         nflag = 1;
 443                         break;
 444                 case 'c':
 445                         sp->c_suffix = !sp->c_suffix;
 446
 447                         /* Ex text structure initialization. */
 448                         if (F_ISSET(sp, SC_EX)) {
 449                                 memset(&tiq, 0, sizeof(TEXTH));
 450                                 CIRCLEQ_INIT(&tiq);
 451                         }
 452                         break;
 453                 case 'g':
 454                         sp->g_suffix = !sp->g_suffix;
 455                         break;
 456                 case 'l':
 457                         lflag = 1;
 458                         break;
 459                 case 'p':
 460                         pflag = 1;
 461                         break;
 462                 case 'r':
 463                         if (LF_ISSET(SUB_FIRST)) {
 464                                 msgq(sp, M_ERR,
 465                     "155|Regular expression specified; r flag meaningless");
 466                                 return (1);
 467                         }
 468                         if (!F_ISSET(sp, SC_RE_SEARCH)) {
 469                                 ex_emsg(sp, NULL, EXM_NOPREVRE);
 470                                 return (1);
 471                         }
 472                         rflag = 1;
 473                         re = &sp->re_c;
 474                         break;
 475                 default:
 476                         goto usage;
 477                 }
 478
 479         if (*s != '\0' || !rflag && LF_ISSET(SUB_MUSTSETR)) {
 480 usage:          ex_emsg(sp, cmdp->cmd->usage, EXM_USAGE);
 481                 return (1);
 482         }
 483
 484 noargs: if (F_ISSET(sp, SC_VI) && sp->c_suffix && (lflag || nflag || pflag)) {
 485                 msgq(sp, M_ERR,
 486 "156|The #, l and p flags may not be combined with the c flag in vi mode");
 487                 return (1);
 488         }
 489
 490         /*
 491          * bp:          if interactive, line cache
 492          * blen:        if interactive, line cache length
 493          * lb:          build buffer pointer.
 494          * lbclen:      current length of built buffer.
 495          * lblen;       length of build buffer.
 496          */
 497         bp = lb = NULL;
 498         blen = lbclen = lblen = 0;
 499
 500         /* For each line... */
 501         lno = cmdp->addr1.lno == 0 ? 1 : cmdp->addr1.lno;
 502         for (matched = quit = 0,
 503             elno = cmdp->addr2.lno; !quit && lno <= elno; ++lno) {
 504
 505                 /* Someone's unhappy, time to stop. */
 506                 if (INTERRUPTED(sp))
 507                         break;
 508
 509                 /* Get the line. */
 510                 if (db_get(sp, lno, DBG_FATAL, &s, &llen))
 511                         goto err;
 512
 513                 /*
 514                  * Make a local copy if doing confirmation -- when calling
 515                  * the confirm routine we're likely to lose the cached copy.
 516                  */
 517                 if (sp->c_suffix) {
 518                         if (bp == NULL) {
 519                                 GET_SPACE_RET(sp, bp, blen, llen);
 520                         } else
 521                                 ADD_SPACE_RET(sp, bp, blen, llen);
 522                         memcpy(bp, s, llen);
 523                         s = bp;
 524                 }
 525
 526                 /* Start searching from the beginning. */
 527                 offset = 0;
 528                 len = llen;
 529
 530                 /* Reset the build buffer offset. */
 531                 lbclen = 0;
 532
 533                 /* Reset empty match flag. */
 534                 empty_ok = 1;
 535
 536                 /*
 537                  * We don't want to have to do a setline if the line didn't
 538                  * change -- keep track of whether or not this line changed.
 539                  * If doing confirmations, don't want to keep setting the
 540                  * line if change is refused -- keep track of substitutions.
 541                  */
 542                 didsub = linechanged = 0;
 543
 544                 /* New line, do an EOL match. */
 545                 do_eol_match = 1;
 546
 547                 /* It's not nul terminated, but we pretend it is. */
 548                 eflags = REG_STARTEND;
 549
 550                 /*
 551                  * The search area is from s + offset to the EOL.
 552                  *
 553                  * Generally, match[0].rm_so is the offset of the start
 554                  * of the match from the start of the search, and offset
 555                  * is the offset of the start of the last search.
 556                  */
 557 nextmatch:      match[0].rm_so = 0;
 558                 match[0].rm_eo = len;
 559
 560                 /* Get the next match. */
 561                 eval = regexec(re, (char *)s + offset, 10, match, eflags);
 562
 563                 /*
 564                  * There wasn't a match or if there was an error, deal with
 565                  * it.  If there was a previous match in this line, resolve
 566                  * the changes into the database.  Otherwise, just move on.
 567                  */
 568                 if (eval == REG_NOMATCH)
 569                         goto endmatch;
 570                 if (eval != 0) {
 571                         re_error(sp, eval, re);
 572                         goto err;
 573                 }
 574                 matched = 1;
 575
 576                 /* Only the first search can match an anchored expression. */
 577                 eflags |= REG_NOTBOL;
 578
 579                 /*
 580                  * !!!
 581                  * It's possible to match 0-length strings -- for example, the
 582                  * command s;a*;X;, when matched against the string "aabb" will
 583                  * result in "XbXbX", i.e. the matches are "aa", the space
 584                  * between the b's and the space between the b's and the end of
 585                  * the string.  There is a similar space between the beginning
 586                  * of the string and the a's.  The rule that we use (because vi
 587                  * historically used it) is that any 0-length match, occurring
 588                  * immediately after a match, is ignored.  Otherwise, the above
 589                  * example would have resulted in "XXbXbX".  Another example is
 590                  * incorrectly using " *" to replace groups of spaces with one
 591                  * space.
 592                  *
 593                  * The way we do this is that if we just had a successful match,
 594                  * the starting offset does not skip characters, and the match
 595                  * is empty, ignore the match and move forward.  If there's no
 596                  * more characters in the string, we were attempting to match
 597                  * after the last character, so quit.
 598                  */
 599                 if (!empty_ok && match[0].rm_so == 0 && match[0].rm_eo == 0) {
 600                         empty_ok = 1;
 601                         if (len == 0)
 602                                 goto endmatch;
 603                         BUILD(sp, s + offset, 1)
 604                         ++offset;
 605                         --len;
 606                         goto nextmatch;
 607                 }
 608
 609                 /* Confirm change. */
 610                 if (sp->c_suffix) {
 611                         /*
 612                          * Set the cursor position for confirmation.  Note,
 613                          * if we matched on a '$', the cursor may be past
 614                          * the end of line.
 615                          */
 616                         from.lno = to.lno = lno;
 617                         from.cno = match[0].rm_so + offset;
 618                         to.cno = match[0].rm_eo + offset;
 619                         /*
 620                          * Both ex and vi have to correct for a change before
 621                          * the first character in the line.
 622                          */
 623                         if (llen == 0)
 624                                 from.cno = to.cno = 0;
 625                         if (F_ISSET(sp, SC_VI)) {
 626                                 /*
 627                                  * Only vi has to correct for a change after
 628                                  * the last character in the line.
 629                                  *
 630                                  * XXX
 631                                  * It would be nice to change the vi code so
 632                                  * that we could display a cursor past EOL.
 633                                  */
 634                                 if (to.cno >= llen)
 635                                         to.cno = llen - 1;
 636                                 if (from.cno >= llen)
 637                                         from.cno = llen - 1;
 638
 639                                 sp->lno = from.lno;
 640                                 sp->cno = from.cno;
 641                                 if (vs_refresh(sp, 1))
 642                                         goto err;
 643
 644                                 vs_update(sp, msg_cat(sp,
 645                                     "169|Confirm change? [n]", NULL), NULL);
 646
 647                                 if (v_event_get(sp, &ev, 0, 0))
 648                                         goto err;
 649                                 switch (ev.e_event) {
 650                                 case E_CHARACTER:
 651                                         break;
 652                                 case E_EOF:
 653                                 case E_ERR:
 654                                 case E_INTERRUPT:
 655                                         goto lquit;
 656                                 default:
 657                                         v_event_err(sp, &ev);
 658                                         goto lquit;
 659                                 }
 660                         } else {
 661                                 if (ex_print(sp, cmdp, &from, &to, 0) ||
 662                                     ex_scprint(sp, &from, &to))
 663                                         goto lquit;
 664                                 if (ex_txt(sp, &tiq, 0, TXT_CR))
 665                                         goto err;
 666                                 ev.e_c = tiq.cqh_first->lb[0];
 667                         }
 668
 669                         switch (ev.e_c) {
 670                         case CH_YES:
 671                                 break;
 672                         default:
 673                         case CH_NO:
 674                                 didsub = 0;
 675                                 BUILD(sp, s +offset, match[0].rm_eo);
 676                                 goto skip;
 677                         case CH_QUIT:
 678                                 /* Set the quit/interrupted flags. */
 679 lquit:                          quit = 1;
 680                                 F_SET(sp->gp, G_INTERRUPTED);
 681
 682                                 /*
 683                                  * Resolve any changes, then return to (and
 684                                  * exit from) the main loop.
 685                                  */
 686                                 goto endmatch;
 687                         }
 688                 }
 689
 690                 /*
 691                  * Set the cursor to the last position changed, converting
 692                  * from 1-based to 0-based.
 693                  */
 694                 sp->lno = lno;
 695                 sp->cno = match[0].rm_so;
 696
 697                 /* Copy the bytes before the match into the build buffer. */
 698                 BUILD(sp, s + offset, match[0].rm_so);
 699
 700                 /* Substitute the matching bytes. */
 701                 didsub = 1;
 702                 if (re_sub(sp, s + offset, &lb, &lbclen, &lblen, match))
 703                         goto err;
 704
 705                 /* Set the change flag so we know this line was modified. */
 706                 linechanged = 1;
 707
 708                 /* Move past the matched bytes. */
 709 skip:           offset += match[0].rm_eo;
 710                 len -= match[0].rm_eo;
 711
 712                 /* A match cannot be followed by an empty pattern. */
 713                 empty_ok = 0;
 714
 715                 /*
 716                  * If doing a global change with confirmation, we have to
 717                  * update the screen.  The basic idea is to store the line
 718                  * so the screen update routines can find it, and restart.
 719                  */
 720                 if (didsub && sp->c_suffix && sp->g_suffix) {
 721                         /*
 722                          * The new search offset will be the end of the
 723                          * modified line.
 724                          */
 725                         saved_offset = lbclen;
 726
 727                         /* Copy the rest of the line. */
 728                         if (len)
 729                                 BUILD(sp, s + offset, len)
 730
 731                         /* Set the new offset. */
 732                         offset = saved_offset;
 733
 734                         /* Store inserted lines, adjusting the build buffer. */
 735                         last = 0;
 736                         if (sp->newl_cnt) {
 737                                 for (cnt = 0;
 738                                     cnt < sp->newl_cnt; ++cnt, ++lno, ++elno) {
 739                                         if (db_insert(sp, lno,
 740                                             lb + last, sp->newl[cnt] - last))
 741                                                 goto err;
 742                                         last = sp->newl[cnt] + 1;
 743                                         ++sp->rptlines[L_ADDED];
 744                                 }
 745                                 lbclen -= last;
 746                                 offset -= last;
 747                                 sp->newl_cnt = 0;
 748                         }
 749
 750                         /* Store and retrieve the line. */
 751                         if (db_set(sp, lno, lb + last, lbclen))
 752                                 goto err;
 753                         if (db_get(sp, lno, DBG_FATAL, &s, &llen))
 754                                 goto err;
 755                         ADD_SPACE_RET(sp, bp, blen, llen)
 756                         memcpy(bp, s, llen);
 757                         s = bp;
 758                         len = llen - offset;
 759
 760                         /* Restart the build. */
 761                         lbclen = 0;
 762                         BUILD(sp, s, offset);
 763
 764                         /*
 765                          * If we haven't already done the after-the-string
 766                          * match, do one.  Set REG_NOTEOL so the '$' pattern
 767                          * only matches once.
 768                          */
 769                         if (!do_eol_match)
 770                                 goto endmatch;
 771                         if (offset == len) {
 772                                 do_eol_match = 0;
 773                                 eflags |= REG_NOTEOL;
 774                         }
 775                         goto nextmatch;
 776                 }
 777
 778                 /*
 779                  * If it's a global:
 780                  *
 781                  * If at the end of the string, do a test for the after
 782                  * the string match.  Set REG_NOTEOL so the '$' pattern
 783                  * only matches once.
 784                  */
 785                 if (sp->g_suffix && do_eol_match) {
 786                         if (len == 0) {
 787                                 do_eol_match = 0;
 788                                 eflags |= REG_NOTEOL;
 789                         }
 790                         goto nextmatch;
 791                 }
 792
 793 endmatch:       if (!linechanged)
 794                         continue;
 795
 796                 /* Copy any remaining bytes into the build buffer. */
 797                 if (len)
 798                         BUILD(sp, s + offset, len)
 799
 800                 /* Store inserted lines, adjusting the build buffer. */
 801                 last = 0;
 802                 if (sp->newl_cnt) {
 803                         for (cnt = 0;
 804                             cnt < sp->newl_cnt; ++cnt, ++lno, ++elno) {
 805                                 if (db_insert(sp,
 806                                     lno, lb + last, sp->newl[cnt] - last))
 807                                         goto err;
 808                                 last = sp->newl[cnt] + 1;
 809                                 ++sp->rptlines[L_ADDED];
 810                         }
 811                         lbclen -= last;
 812                         sp->newl_cnt = 0;
 813                 }
 814
 815                 /* Store the changed line. */
 816                 if (db_set(sp, lno, lb + last, lbclen))
 817                         goto err;
 818
 819                 /* Update changed line counter. */
 820                 if (sp->rptlchange != lno) {
 821                         sp->rptlchange = lno;
 822                         ++sp->rptlines[L_CHANGED];
 823                 }
 824
 825                 /*
 826                  * !!!
 827                  * Display as necessary.  Historic practice is to only
 828                  * display the last line of a line split into multiple
 829                  * lines.
 830                  */
 831                 if (lflag || nflag || pflag) {
 832                         from.lno = to.lno = lno;
 833                         from.cno = to.cno = 0;
 834                         if (lflag)
 835                                 (void)ex_print(sp, cmdp, &from, &to, E_C_LIST);
 836                         if (nflag)
 837                                 (void)ex_print(sp, cmdp, &from, &to, E_C_HASH);
 838                         if (pflag)
 839                                 (void)ex_print(sp, cmdp, &from, &to, E_C_PRINT);
 840                 }
 841         }
 842
 843         /*
 844          * !!!
 845          * Historically, vi attempted to leave the cursor at the same place if
 846          * the substitution was done at the current cursor position.  Otherwise
 847          * it moved it to the first non-blank of the last line changed.  There
 848          * were some problems: for example, :s/$/foo/ with the cursor on the
 849          * last character of the line left the cursor on the last character, or
 850          * the & command with multiple occurrences of the matching string in the
 851          * line usually left the cursor in a fairly random position.
 852          *
 853          * We try to do the same thing, with the exception that if the user is
 854          * doing substitution with confirmation, we move to the last line about
 855          * which the user was consulted, as opposed to the last line that they
 856          * actually changed.  This prevents a screen flash if the user doesn't
 857          * change many of the possible lines.
 858          */
 859         if (!sp->c_suffix && (sp->lno != slno || sp->cno != scno)) {
 860                 sp->cno = 0;
 861                 (void)nonblank(sp, sp->lno, &sp->cno);
 862         }
 863
 864         /*
 865          * If not in a global command, and nothing matched, say so.
 866          * Else, if none of the lines displayed, put something up.
 867          */
 868         rval = 0;
 869         if (!matched) {
 870                 if (!F_ISSET(sp, SC_EX_GLOBAL)) {
 871                         msgq(sp, M_ERR, "157|No match found");
 872                         goto err;
 873                 }
 874         } else if (!lflag && !nflag && !pflag)
 875                 F_SET(cmdp, E_AUTOPRINT);
 876
 877         if (0) {
 878 err:            rval = 1;
 879         }
 880
 881         if (bp != NULL)
 882                 FREE_SPACE(sp, bp, blen);
 883         if (lb != NULL)
 884                 free(lb);
 885         return (rval);
 886 }
 887
 888 /*
 889  * re_compile --
 890  *      Compile the RE.
 891  *
 892  * PUBLIC: int re_compile __P((SCR *,
 893  * PUBLIC:     char *, size_t, char **, size_t *, regex_t *, u_int));
 894  */
 895 int
 896 re_compile(sp, ptrn, plen, ptrnp, lenp, rep, flags)
 897         SCR *sp;
 898         char *ptrn, **ptrnp;
 899         size_t plen, *lenp;
 900         regex_t *rep;
 901         u_int flags;
 902 {
 903         size_t len;
 904         int reflags, replaced, rval;
 905         char *p;
 906
 907         /* Set RE flags. */
 908         reflags = 0;
 909         if (LF_ISSET(SEARCH_EXTEND))
 910                 reflags |= REG_EXTENDED;
 911         if (LF_ISSET(SEARCH_IC))
 912                 reflags |= REG_ICASE;
 913         if (LF_ISSET(SEARCH_LITERAL))
 914                 reflags |= REG_NOSPEC;
 915         if (!LF_ISSET(SEARCH_NOOPT | SEARCH_CSCOPE | SEARCH_TAG)) {
 916                 if (O_ISSET(sp, O_EXTENDED))
 917                         reflags |= REG_EXTENDED;
 918                 if (O_ISSET(sp, O_IGNORECASE))
 919                         reflags |= REG_ICASE;
 920                 if (O_ISSET(sp, O_ICLOWER))
 921                         goto iclower;
 922         }
 923         if (LF_ISSET(SEARCH_ICL)) {
 924 iclower:        for (p = ptrn, len = plen; len > 0; ++p, --len)
 925                         if (isupper(*p))
 926                                 break;
 927                 if (len == 0)
 928                         reflags |= REG_ICASE;
 929         }
 930
 931         /* If we're replacing a saved value, clear the old one. */
 932         if (LF_ISSET(SEARCH_CSEARCH) && F_ISSET(sp, SC_RE_SEARCH)) {
 933                 regfree(&sp->re_c);
 934                 F_CLR(sp, SC_RE_SEARCH);
 935         }
 936         if (LF_ISSET(SEARCH_CSUBST) && F_ISSET(sp, SC_RE_SUBST)) {
 937                 regfree(&sp->subre_c);
 938                 F_CLR(sp, SC_RE_SUBST);
 939         }
 940
 941         /*
 942          * If we're saving the string, it's a pattern we haven't seen before,
 943          * so convert the vi-style RE's to POSIX 1003.2 RE's.  Save a copy for
 944          * later recompilation.   Free any previously saved value.
 945          */
 946         if (ptrnp != NULL) {
 947                 replaced = 0;
 948                 if (LF_ISSET(SEARCH_CSCOPE)) {
 949                         if (re_cscope_conv(sp, &ptrn, &plen, &replaced))
 950                                 return (1);
 951                         /*
 952                          * XXX
 953                          * Currently, the match-any-<blank> expression used in
 954                          * re_cscope_conv() requires extended RE's.  This may
 955                          * not be right or safe.
 956                          */
 957                         reflags |= REG_EXTENDED;
 958                 } else if (LF_ISSET(SEARCH_TAG)) {
 959                         if (re_tag_conv(sp, &ptrn, &plen, &replaced))
 960                                 return (1);
 961                 } else if (!LF_ISSET(SEARCH_LITERAL))
 962                         if (re_conv(sp, &ptrn, &plen, &replaced))
 963                                 return (1);
 964
 965                 /* Discard previous pattern. */
 966                 if (*ptrnp != NULL) {
 967                         free(*ptrnp);
 968                         *ptrnp = NULL;
 969                 }
 970                 if (lenp != NULL)
 971                         *lenp = plen;
 972
 973                 /*
 974                  * Copy the string into allocated memory.
 975                  *
 976                  * XXX
 977                  * Regcomp isn't 8-bit clean, so the pattern is nul-terminated
 978                  * for now.  There's just no other solution.
 979                  */
 980                 MALLOC(sp, *ptrnp, char *, plen + 1);
 981                 if (*ptrnp != NULL) {
 982                         memcpy(*ptrnp, ptrn, plen);
 983                         (*ptrnp)[plen] = '\0';
 984                 }
 985
 986                 /* Free up conversion-routine-allocated memory. */
 987                 if (replaced)
 988                         FREE_SPACE(sp, ptrn, 0);
 989
 990                 if (*ptrnp == NULL)
 991                         return (1);
 992
 993                 ptrn = *ptrnp;
 994         }
 995
 996         /*
 997          * XXX
 998          * Regcomp isn't 8-bit clean, so we just lost if the pattern
 999          * contained a nul.  Bummer!
1000          */
1001         if ((rval = regcomp(rep, ptrn, /* plen, */ reflags)) != 0) {
1002                 if (LF_ISSET(SEARCH_MSG))
1003                         re_error(sp, rval, rep);
1004                 return (1);
1005         }
1006
1007         if (LF_ISSET(SEARCH_CSEARCH))
1008                 F_SET(sp, SC_RE_SEARCH);
1009         if (LF_ISSET(SEARCH_CSUBST))
1010                 F_SET(sp, SC_RE_SUBST);
1011
1012         return (0);
1013 }
1014
1015 /*
1016  * re_conv --
1017  *      Convert vi's regular expressions into something that the
1018  *      the POSIX 1003.2 RE functions can handle.
1019  *
1020  * There are three conversions we make to make vi's RE's (specifically
1021  * the global, search, and substitute patterns) work with POSIX RE's.
1022  *
1023  * 1: If O_MAGIC is not set, strip backslashes from the magic character
1024  *    set (.[*~) that have them, and add them to the ones that don't.
1025  * 2: If O_MAGIC is not set, the string "\~" is replaced with the text
1026  *    from the last substitute command's replacement string.  If O_MAGIC
1027  *    is set, it's the string "~".
1028  * 3: The pattern \<ptrn\> does "word" searches, convert it to use the
1029  *    new RE escapes.
1030  *
1031  * !!!/XXX
1032  * This doesn't exactly match the historic behavior of vi because we do
1033  * the ~ substitution before calling the RE engine, so magic characters
1034  * in the replacement string will be expanded by the RE engine, and they
1035  * weren't historically.  It's a bug.
1036  */
1037 static int
1038 re_conv(sp, ptrnp, plenp, replacedp)
1039         SCR *sp;
1040         char **ptrnp;
1041         size_t *plenp;
1042         int *replacedp;
1043 {
1044         size_t blen, len, needlen;
1045         int magic;
1046         char *bp, *p, *t;
1047
1048         /*
1049          * First pass through, we figure out how much space we'll need.
1050          * We do it in two passes, on the grounds that most of the time
1051          * the user is doing a search and won't have magic characters.
1052          * That way we can skip most of the memory allocation and copies.
1053          */
1054         magic = 0;
1055         for (p = *ptrnp, len = *plenp, needlen = 0; len > 0; ++p, --len)
1056                 switch (*p) {
1057                 case '\\':
1058                         if (len > 1) {
1059                                 --len;
1060                                 switch (*++p) {
1061                                 case '<':
1062                                         magic = 1;
1063                                         needlen += sizeof(RE_WSTART);
1064                                         break;
1065                                 case '>':
1066                                         magic = 1;
1067                                         needlen += sizeof(RE_WSTOP);
1068                                         break;
1069                                 case '~':
1070                                         if (!O_ISSET(sp, O_MAGIC)) {
1071                                                 magic = 1;
1072                                                 needlen += sp->repl_len;
1073                                         }
1074                                         break;
1075                                 case '.':
1076                                 case '[':
1077                                 case '*':
1078                                         if (!O_ISSET(sp, O_MAGIC)) {
1079                                                 magic = 1;
1080                                                 needlen += 1;
1081                                         }
1082                                         break;
1083                                 default:
1084                                         needlen += 2;
1085                                 }
1086                         } else
1087                                 needlen += 1;
1088                         break;
1089                 case '~':
1090                         if (O_ISSET(sp, O_MAGIC)) {
1091                                 magic = 1;
1092                                 needlen += sp->repl_len;
1093                         }
1094                         break;
1095                 case '.':
1096                 case '[':
1097                 case '*':
1098                         if (!O_ISSET(sp, O_MAGIC)) {
1099                                 magic = 1;
1100                                 needlen += 2;
1101                         }
1102                         break;
1103                 default:
1104                         needlen += 1;
1105                         break;
1106                 }
1107
1108         if (!magic) {
1109                 *replacedp = 0;
1110                 return (0);
1111         }
1112
1113         /* Get enough memory to hold the final pattern. */
1114         *replacedp = 1;
1115         GET_SPACE_RET(sp, bp, blen, needlen);
1116
1117         for (p = *ptrnp, len = *plenp, t = bp; len > 0; ++p, --len)
1118                 switch (*p) {
1119                 case '\\':
1120                         if (len > 1) {
1121                                 --len;
1122                                 switch (*++p) {
1123                                 case '<':
1124                                         memcpy(t,
1125                                             RE_WSTART, sizeof(RE_WSTART) - 1);
1126                                         t += sizeof(RE_WSTART) - 1;
1127                                         break;
1128                                 case '>':
1129                                         memcpy(t,
1130                                             RE_WSTOP, sizeof(RE_WSTOP) - 1);
1131                                         t += sizeof(RE_WSTOP) - 1;
1132                                         break;
1133                                 case '~':
1134                                         if (O_ISSET(sp, O_MAGIC))
1135                                                 *t++ = '~';
1136                                         else {
1137                                                 memcpy(t,
1138                                                     sp->repl, sp->repl_len);
1139                                                 t += sp->repl_len;
1140                                         }
1141                                         break;
1142                                 case '.':
1143                                 case '[':
1144                                 case '*':
1145                                         if (O_ISSET(sp, O_MAGIC))
1146                                                 *t++ = '\\';
1147                                         *t++ = *p;
1148                                         break;
1149                                 default:
1150                                         *t++ = '\\';
1151                                         *t++ = *p;
1152                                 }
1153                         } else
1154                                 *t++ = '\\';
1155                         break;
1156                 case '~':
1157                         if (O_ISSET(sp, O_MAGIC)) {
1158                                 memcpy(t, sp->repl, sp->repl_len);
1159                                 t += sp->repl_len;
1160                         } else
1161                                 *t++ = '~';
1162                         break;
1163                 case '.':
1164                 case '[':
1165                 case '*':
1166                         if (!O_ISSET(sp, O_MAGIC))
1167                                 *t++ = '\\';
1168                         *t++ = *p;
1169                         break;
1170                 default:
1171                         *t++ = *p;
1172                         break;
1173                 }
1174
1175         *ptrnp = bp;
1176         *plenp = t - bp;
1177         return (0);
1178 }
1179
1180 /*
1181  * re_tag_conv --
1182  *      Convert a tags search path into something that the POSIX
1183  *      1003.2 RE functions can handle.
1184  */
1185 static int
1186 re_tag_conv(sp, ptrnp, plenp, replacedp)
1187         SCR *sp;
1188         char **ptrnp;
1189         size_t *plenp;
1190         int *replacedp;
1191 {
1192         size_t blen, len;
1193         int lastdollar;
1194         char *bp, *p, *t;
1195
1196         len = *plenp;
1197
1198         /* Max memory usage is 2 times the length of the string. */
1199         *replacedp = 1;
1200         GET_SPACE_RET(sp, bp, blen, len * 2);
1201
1202         p = *ptrnp;
1203         t = bp;
1204
1205         /* If the last character is a '/' or '?', we just strip it. */
1206         if (len > 0 && (p[len - 1] == '/' || p[len - 1] == '?'))
1207                 --len;
1208
1209         /* If the next-to-last or last character is a '$', it's magic. */
1210         if (len > 0 && p[len - 1] == '$') {
1211                 --len;
1212                 lastdollar = 1;
1213         } else
1214                 lastdollar = 0;
1215
1216         /* If the first character is a '/' or '?', we just strip it. */
1217         if (len > 0 && (p[0] == '/' || p[0] == '?')) {
1218                 ++p;
1219                 --len;
1220         }
1221
1222         /* If the first or second character is a '^', it's magic. */
1223         if (p[0] == '^') {
1224                 *t++ = *p++;
1225                 --len;
1226         }
1227
1228         /*
1229          * Escape every other magic character we can find, meanwhile stripping
1230          * the backslashes ctags inserts when escaping the search delimiter
1231          * characters.
1232          */
1233         for (; len > 0; --len) {
1234                 if (p[0] == '\\' && (p[1] == '/' || p[1] == '?')) {
1235                         ++p;
1236                         --len;
1237                 } else if (strchr("^.[]$*", p[0]))
1238                         *t++ = '\\';
1239                 *t++ = *p++;
1240         }
1241         if (lastdollar)
1242                 *t++ = '$';
1243
1244         *ptrnp = bp;
1245         *plenp = t - bp;
1246         return (0);
1247 }
1248
1249 /*
1250  * re_cscope_conv --
1251  *       Convert a cscope search path into something that the POSIX
1252  *      1003.2 RE functions can handle.
1253  */
1254 static int
1255 re_cscope_conv(sp, ptrnp, plenp, replacedp)
1256         SCR *sp;
1257         char **ptrnp;
1258         size_t *plenp;
1259         int *replacedp;
1260 {
1261         size_t blen, len, nspaces;
1262         char *bp, *p, *t;
1263
1264         /*
1265          * Each space in the source line printed by cscope represents an
1266          * arbitrary sequence of spaces, tabs, and comments.
1267          */
1268 #define CSCOPE_RE_SPACE         "([ \t]|/\\*([^*]|\\*/)*\\*/)*"
1269         for (nspaces = 0, p = *ptrnp, len = *plenp; len > 0; ++p, --len)
1270                 if (*p == ' ')
1271                         ++nspaces;
1272
1273         /*
1274          * Allocate plenty of space:
1275          *      the string, plus potential escaping characters;
1276          *      nspaces + 2 copies of CSCOPE_RE_SPACE;
1277          *      ^, $, nul terminator characters.
1278          */
1279         *replacedp = 1;
1280         len = (p - *ptrnp) * 2 + (nspaces + 2) * sizeof(CSCOPE_RE_SPACE) + 3;
1281         GET_SPACE_RET(sp, bp, blen, len);
1282
1283         p = *ptrnp;
1284         t = bp;
1285
1286         *t++ = '^';
1287         memcpy(t, CSCOPE_RE_SPACE, sizeof(CSCOPE_RE_SPACE) - 1);
1288         t += sizeof(CSCOPE_RE_SPACE) - 1;
1289
1290         for (len = *plenp; len > 0; ++p, --len)
1291                 if (*p == ' ') {
1292                         memcpy(t, CSCOPE_RE_SPACE, sizeof(CSCOPE_RE_SPACE) - 1);
1293                         t += sizeof(CSCOPE_RE_SPACE) - 1;
1294                 } else {
1295                         if (strchr("\\^.[]$*+?()|{}", *p))
1296                                 *t++ = '\\';
1297                         *t++ = *p;
1298                 }
1299
1300         memcpy(t, CSCOPE_RE_SPACE, sizeof(CSCOPE_RE_SPACE) - 1);
1301         t += sizeof(CSCOPE_RE_SPACE) - 1;
1302         *t++ = '$';
1303
1304         *ptrnp = bp;
1305         *plenp = t - bp;
1306         return (0);
1307 }
1308
1309 /*
1310  * re_error --
1311  *      Report a regular expression error.
1312  *
1313  * PUBLIC: void re_error __P((SCR *, int, regex_t *));
1314  */
1315 void
1316 re_error(sp, errcode, preg)
1317         SCR *sp;
1318         int errcode;
1319         regex_t *preg;
1320 {
1321         size_t s;
1322         char *oe;
1323
1324         s = regerror(errcode, preg, "", 0);
1325         if ((oe = malloc(s)) == NULL)
1326                 msgq(sp, M_SYSERR, NULL);
1327         else {
1328                 (void)regerror(errcode, preg, oe, s);
1329                 msgq(sp, M_ERR, "RE error: %s", oe);
1330                 free(oe);
1331         }
1332 }
1333
1334 /*
1335  * re_sub --
1336  *      Do the substitution for a regular expression.
1337  */
1338 static int
1339 re_sub(sp, ip, lbp, lbclenp, lblenp, match)
1340         SCR *sp;
1341         char *ip;                       /* Input line. */
1342         char **lbp;
1343         size_t *lbclenp, *lblenp;
1344         regmatch_t match[10];
1345 {
1346         enum { C_NOTSET, C_LOWER, C_ONELOWER, C_ONEUPPER, C_UPPER } conv;
1347         size_t lbclen, lblen;           /* Local copies. */
1348         size_t mlen;                    /* Match length. */
1349         size_t rpl;                     /* Remaining replacement length. */
1350         char *rp;                       /* Replacement pointer. */
1351         int ch;
1352         int no;                         /* Match replacement offset. */
1353         char *p, *t;                    /* Buffer pointers. */
1354         char *lb;                       /* Local copies. */
1355
1356         lb = *lbp;                      /* Get local copies. */
1357         lbclen = *lbclenp;
1358         lblen = *lblenp;
1359
1360         /*
1361          * QUOTING NOTE:
1362          *
1363          * There are some special sequences that vi provides in the
1364          * replacement patterns.
1365          *       & string the RE matched (\& if nomagic set)
1366          *      \# n-th regular subexpression
1367          *      \E end \U, \L conversion
1368          *      \e end \U, \L conversion
1369          *      \l convert the next character to lower-case
1370          *      \L convert to lower-case, until \E, \e, or end of replacement
1371          *      \u convert the next character to upper-case
1372          *      \U convert to upper-case, until \E, \e, or end of replacement
1373          *
1374          * Otherwise, since this is the lowest level of replacement, discard
1375          * all escaping characters.  This (hopefully) matches historic practice.
1376          */
1377 #define OUTCH(ch, nltrans) {                                            \
1378         CHAR_T __ch = (ch);                                             \
1379         u_int __value = KEY_VAL(sp, __ch);                              \
1380         if (nltrans && (__value == K_CR || __value == K_NL)) {          \
1381                 NEEDNEWLINE(sp);                                        \
1382                 sp->newl[sp->newl_cnt++] = lbclen;                      \
1383         } else if (conv != C_NOTSET) {                                  \
1384                 switch (conv) {                                         \
1385                 case C_ONELOWER:                                        \
1386                         conv = C_NOTSET;                                \
1387                         /* FALLTHROUGH */                               \
1388                 case C_LOWER:                                           \
1389                         if (isupper(__ch))                              \
1390                                 __ch = tolower(__ch);                   \
1391                         break;                                          \
1392                 case C_ONEUPPER:                                        \
1393                         conv = C_NOTSET;                                \
1394                         /* FALLTHROUGH */                               \
1395                 case C_UPPER:                                           \
1396                         if (islower(__ch))                              \
1397                                 __ch = toupper(__ch);                   \
1398                         break;                                          \
1399                 default:                                                \
1400                         abort();                                        \
1401                 }                                                       \
1402         }                                                               \
1403         NEEDSP(sp, 1, p);                                               \
1404         *p++ = __ch;                                                    \
1405         ++lbclen;                                                       \
1406 }
1407         conv = C_NOTSET;
1408         for (rp = sp->repl, rpl = sp->repl_len, p = lb + lbclen; rpl--;) {
1409                 switch (ch = *rp++) {
1410                 case '&':
1411                         if (O_ISSET(sp, O_MAGIC)) {
1412                                 no = 0;
1413                                 goto subzero;
1414                         }
1415                         break;
1416                 case '\\':
1417                         if (rpl == 0)
1418                                 break;
1419                         --rpl;
1420                         switch (ch = *rp) {
1421                         case '&':
1422                                 ++rp;
1423                                 if (!O_ISSET(sp, O_MAGIC)) {
1424                                         no = 0;
1425                                         goto subzero;
1426                                 }
1427                                 break;
1428                         case '0': case '1': case '2': case '3': case '4':
1429                         case '5': case '6': case '7': case '8': case '9':
1430                                 no = *rp++ - '0';
1431 subzero:                        if (match[no].rm_so == -1 ||
1432                                     match[no].rm_eo == -1)
1433                                         break;
1434                                 mlen = match[no].rm_eo - match[no].rm_so;
1435                                 for (t = ip + match[no].rm_so; mlen--; ++t)
1436                                         OUTCH(*t, 0);
1437                                 continue;
1438                         case 'e':
1439                         case 'E':
1440                                 ++rp;
1441                                 conv = C_NOTSET;
1442                                 continue;
1443                         case 'l':
1444                                 ++rp;
1445                                 conv = C_ONELOWER;
1446                                 continue;
1447                         case 'L':
1448                                 ++rp;
1449                                 conv = C_LOWER;
1450                                 continue;
1451                         case 'u':
1452                                 ++rp;
1453                                 conv = C_ONEUPPER;
1454                                 continue;
1455                         case 'U':
1456                                 ++rp;
1457                                 conv = C_UPPER;
1458                                 continue;
1459                         default:
1460                                 ++rp;
1461                                 break;
1462                         }
1463                 }
1464                 OUTCH(ch, 1);
1465         }
1466
1467         *lbp = lb;                      /* Update caller's information. */
1468         *lbclenp = lbclen;
1469         *lblenp = lblen;
1470         return (0);
1471 }