mansearch.c

   1 /*      $OpenBSD: mansearch.c,v 1.50 2016/07/09 15:23:36 schwarze Exp $ */
   2 /*
   3  * Copyright (c) 2012 Kristaps Dzonsons <kristaps@bsd.lv>
   4  * Copyright (c) 2013-2017 Ingo Schwarze <schwarze@openbsd.org>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18 #include "config.h"
  19
  20 #include <sys/mman.h>
  21 #include <sys/types.h>
  22
  23 #include <assert.h>
  24 #if HAVE_ERR
  25 #include <err.h>
  26 #endif
  27 #include <errno.h>
  28 #include <fcntl.h>
  29 #include <glob.h>
  30 #include <limits.h>
  31 #include <regex.h>
  32 #include <stdio.h>
  33 #include <stdint.h>
  34 #include <stddef.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <unistd.h>
  38
  39 #include "mandoc.h"
  40 #include "mandoc_aux.h"
  41 #include "mandoc_ohash.h"
  42 #include "manconf.h"
  43 #include "mansearch.h"
  44 #include "dbm.h"
  45
  46 struct  expr {
  47         /* Used for terms: */
  48         struct dbm_match match;   /* Match type and expression. */
  49         uint64_t         bits;    /* Type mask. */
  50         /* Used for OR and AND groups: */
  51         struct expr     *next;    /* Next child in the parent group. */
  52         struct expr     *child;   /* First child in this group. */
  53         enum { EXPR_TERM, EXPR_OR, EXPR_AND } type;
  54 };
  55
  56 const char *const mansearch_keynames[KEY_MAX] = {
  57         "arch", "sec",  "Xr",   "Ar",   "Fa",   "Fl",   "Dv",   "Fn",
  58         "Ic",   "Pa",   "Cm",   "Li",   "Em",   "Cd",   "Va",   "Ft",
  59         "Tn",   "Er",   "Ev",   "Sy",   "Sh",   "In",   "Ss",   "Ox",
  60         "An",   "Mt",   "St",   "Bx",   "At",   "Nx",   "Fx",   "Lk",
  61         "Ms",   "Bsx",  "Dx",   "Rs",   "Vt",   "Lb",   "Nm",   "Nd"
  62 };
  63
  64
  65 static  struct ohash    *manmerge(struct expr *, struct ohash *);
  66 static  struct ohash    *manmerge_term(struct expr *, struct ohash *);
  67 static  struct ohash    *manmerge_or(struct expr *, struct ohash *);
  68 static  struct ohash    *manmerge_and(struct expr *, struct ohash *);
  69 static  char            *buildnames(const struct dbm_page *);
  70 static  char            *buildoutput(size_t, struct dbm_page *);
  71 static  size_t           lstlen(const char *, size_t);
  72 static  void             lstcat(char *, size_t *, const char *, const char *);
  73 static  int              lstmatch(const char *, const char *);
  74 static  struct expr     *exprcomp(const struct mansearch *,
  75                                 int, char *[], int *);
  76 static  struct expr     *expr_and(const struct mansearch *,
  77                                 int, char *[], int *);
  78 static  struct expr     *exprterm(const struct mansearch *,
  79                                 int, char *[], int *);
  80 static  void             exprfree(struct expr *);
  81 static  int              manpage_compare(const void *, const void *);
  82
  83
  84 int
  85 mansearch(const struct mansearch *search,
  86                 const struct manpaths *paths,
  87                 int argc, char *argv[],
  88                 struct manpage **res, size_t *sz)
  89 {
  90         char             buf[PATH_MAX];
  91         struct dbm_res  *rp;
  92         struct expr     *e;
  93         struct dbm_page *page;
  94         struct manpage  *mpage;
  95         struct ohash    *htab;
  96         size_t           cur, i, maxres, outkey;
  97         unsigned int     slot;
  98         int              argi, chdir_status, getcwd_status, im;
  99
 100         argi = 0;
 101         if ((e = exprcomp(search, argc, argv, &argi)) == NULL) {
 102                 *sz = 0;
 103                 return 0;
 104         }
 105
 106         cur = maxres = 0;
 107         *res = NULL;
 108
 109         outkey = KEY_Nd;
 110         if (search->outkey != NULL)
 111                 for (im = 0; im < KEY_MAX; im++)
 112                         if (0 == strcasecmp(search->outkey,
 113                             mansearch_keynames[im])) {
 114                                 outkey = im;
 115                                 break;
 116                         }
 117
 118         /*
 119          * Remember the original working directory, if possible.
 120          * This will be needed if the second or a later directory
 121          * is given as a relative path.
 122          * Do not error out if the current directory is not
 123          * searchable: Maybe it won't be needed after all.
 124          */
 125
 126         if (getcwd(buf, PATH_MAX) == NULL) {
 127                 getcwd_status = 0;
 128                 (void)strlcpy(buf, strerror(errno), sizeof(buf));
 129         } else
 130                 getcwd_status = 1;
 131
 132         /*
 133          * Loop over the directories (containing databases) for us to
 134          * search.
 135          * Don't let missing/bad databases/directories phase us.
 136          * In each, try to open the resident database and, if it opens,
 137          * scan it for our match expression.
 138          */
 139
 140         chdir_status = 0;
 141         for (i = 0; i < paths->sz; i++) {
 142                 if (chdir_status && paths->paths[i][0] != '/') {
 143                         if ( ! getcwd_status) {
 144                                 warnx("%s: getcwd: %s", paths->paths[i], buf);
 145                                 continue;
 146                         } else if (chdir(buf) == -1) {
 147                                 warn("%s", buf);
 148                                 continue;
 149                         }
 150                 }
 151                 if (chdir(paths->paths[i]) == -1) {
 152                         warn("%s", paths->paths[i]);
 153                         continue;
 154                 }
 155                 chdir_status = 1;
 156
 157                 if (dbm_open(MANDOC_DB) == -1) {
 158                         if (errno != ENOENT)
 159                                 warn("%s/%s", paths->paths[i], MANDOC_DB);
 160                         continue;
 161                 }
 162
 163                 if ((htab = manmerge(e, NULL)) == NULL) {
 164                         dbm_close();
 165                         continue;
 166                 }
 167
 168                 for (rp = ohash_first(htab, &slot); rp != NULL;
 169                     rp = ohash_next(htab, &slot)) {
 170                         page = dbm_page_get(rp->page);
 171
 172                         if (lstmatch(search->sec, page->sect) == 0 ||
 173                             lstmatch(search->arch, page->arch) == 0)
 174                                 continue;
 175
 176                         if (cur + 1 > maxres) {
 177                                 maxres += 1024;
 178                                 *res = mandoc_reallocarray(*res,
 179                                     maxres, sizeof(**res));
 180                         }
 181                         mpage = *res + cur;
 182                         mandoc_asprintf(&mpage->file, "%s/%s",
 183                             paths->paths[i], page->file + 1);
 184                         mpage->names = buildnames(page);
 185                         mpage->output = buildoutput(outkey, page);
 186                         mpage->ipath = i;
 187                         mpage->bits = rp->bits;
 188                         mpage->sec = *page->sect - '0';
 189                         if (mpage->sec < 0 || mpage->sec > 9)
 190                                 mpage->sec = 10;
 191                         mpage->form = *page->file;
 192                         free(rp);
 193                         cur++;
 194                 }
 195                 ohash_delete(htab);
 196                 free(htab);
 197                 dbm_close();
 198
 199                 /*
 200                  * In man(1) mode, prefer matches in earlier trees
 201                  * over matches in later trees.
 202                  */
 203
 204                 if (cur && search->firstmatch)
 205                         break;
 206         }
 207         qsort(*res, cur, sizeof(struct manpage), manpage_compare);
 208         if (chdir_status && getcwd_status && chdir(buf) == -1)
 209                 warn("%s", buf);
 210         exprfree(e);
 211         *sz = cur;
 212         return 1;
 213 }
 214
 215 /*
 216  * Merge the results for the expression tree rooted at e
 217  * into the the result list htab.
 218  */
 219 static struct ohash *
 220 manmerge(struct expr *e, struct ohash *htab)
 221 {
 222         switch (e->type) {
 223         case EXPR_TERM:
 224                 return manmerge_term(e, htab);
 225         case EXPR_OR:
 226                 return manmerge_or(e->child, htab);
 227         case EXPR_AND:
 228                 return manmerge_and(e->child, htab);
 229         default:
 230                 abort();
 231         }
 232 }
 233
 234 static struct ohash *
 235 manmerge_term(struct expr *e, struct ohash *htab)
 236 {
 237         struct dbm_res   res, *rp;
 238         uint64_t         ib;
 239         unsigned int     slot;
 240         int              im;
 241
 242         if (htab == NULL) {
 243                 htab = mandoc_malloc(sizeof(*htab));
 244                 mandoc_ohash_init(htab, 4, offsetof(struct dbm_res, page));
 245         }
 246
 247         for (im = 0, ib = 1; im < KEY_MAX; im++, ib <<= 1) {
 248                 if ((e->bits & ib) == 0)
 249                         continue;
 250
 251                 switch (ib) {
 252                 case TYPE_arch:
 253                         dbm_page_byarch(&e->match);
 254                         break;
 255                 case TYPE_sec:
 256                         dbm_page_bysect(&e->match);
 257                         break;
 258                 case TYPE_Nm:
 259                         dbm_page_byname(&e->match);
 260                         break;
 261                 case TYPE_Nd:
 262                         dbm_page_bydesc(&e->match);
 263                         break;
 264                 default:
 265                         dbm_page_bymacro(im - 2, &e->match);
 266                         break;
 267                 }
 268
 269                 /*
 270                  * When hashing for deduplication, use the unique
 271                  * page ID itself instead of a hash function;
 272                  * that is quite efficient.
 273                  */
 274
 275                 for (;;) {
 276                         res = dbm_page_next();
 277                         if (res.page == -1)
 278                                 break;
 279                         slot = ohash_lookup_memory(htab,
 280                             (char *)&res, sizeof(res.page), res.page);
 281                         if ((rp = ohash_find(htab, slot)) != NULL) {
 282                                 rp->bits |= res.bits;
 283                                 continue;
 284                         }
 285                         rp = mandoc_malloc(sizeof(*rp));
 286                         *rp = res;
 287                         ohash_insert(htab, slot, rp);
 288                 }
 289         }
 290         return htab;
 291 }
 292
 293 static struct ohash *
 294 manmerge_or(struct expr *e, struct ohash *htab)
 295 {
 296         while (e != NULL) {
 297                 htab = manmerge(e, htab);
 298                 e = e->next;
 299         }
 300         return htab;
 301 }
 302
 303 static struct ohash *
 304 manmerge_and(struct expr *e, struct ohash *htab)
 305 {
 306         struct ohash    *hand, *h1, *h2;
 307         struct dbm_res  *res;
 308         unsigned int     slot1, slot2;
 309
 310         /* Evaluate the first term of the AND clause. */
 311
 312         hand = manmerge(e, NULL);
 313
 314         while ((e = e->next) != NULL) {
 315
 316                 /* Evaluate the next term and prepare for ANDing. */
 317
 318                 h2 = manmerge(e, NULL);
 319                 if (ohash_entries(h2) < ohash_entries(hand)) {
 320                         h1 = h2;
 321                         h2 = hand;
 322                 } else
 323                         h1 = hand;
 324                 hand = mandoc_malloc(sizeof(*hand));
 325                 mandoc_ohash_init(hand, 4, offsetof(struct dbm_res, page));
 326
 327                 /* Keep all pages that are in both result sets. */
 328
 329                 for (res = ohash_first(h1, &slot1); res != NULL;
 330                     res = ohash_next(h1, &slot1)) {
 331                         if (ohash_find(h2, ohash_lookup_memory(h2,
 332                             (char *)res, sizeof(res->page),
 333                             res->page)) == NULL)
 334                                 free(res);
 335                         else
 336                                 ohash_insert(hand, ohash_lookup_memory(hand,
 337                                     (char *)res, sizeof(res->page),
 338                                     res->page), res);
 339                 }
 340
 341                 /* Discard the merged results. */
 342
 343                 for (res = ohash_first(h2, &slot2); res != NULL;
 344                     res = ohash_next(h2, &slot2))
 345                         free(res);
 346                 ohash_delete(h2);
 347                 free(h2);
 348                 ohash_delete(h1);
 349                 free(h1);
 350         }
 351
 352         /* Merge the result of the AND into htab. */
 353
 354         if (htab == NULL)
 355                 return hand;
 356
 357         for (res = ohash_first(hand, &slot1); res != NULL;
 358             res = ohash_next(hand, &slot1)) {
 359                 slot2 = ohash_lookup_memory(htab,
 360                     (char *)res, sizeof(res->page), res->page);
 361                 if (ohash_find(htab, slot2) == NULL)
 362                         ohash_insert(htab, slot2, res);
 363                 else
 364                         free(res);
 365         }
 366
 367         /* Discard the merged result. */
 368
 369         ohash_delete(hand);
 370         free(hand);
 371         return htab;
 372 }
 373
 374 void
 375 mansearch_free(struct manpage *res, size_t sz)
 376 {
 377         size_t   i;
 378
 379         for (i = 0; i < sz; i++) {
 380                 free(res[i].file);
 381                 free(res[i].names);
 382                 free(res[i].output);
 383         }
 384         free(res);
 385 }
 386
 387 static int
 388 manpage_compare(const void *vp1, const void *vp2)
 389 {
 390         const struct manpage    *mp1, *mp2;
 391         int                      diff;
 392
 393         mp1 = vp1;
 394         mp2 = vp2;
 395         return (diff = mp2->bits - mp1->bits) ? diff :
 396             (diff = mp1->sec - mp2->sec) ? diff :
 397             strcasecmp(mp1->names, mp2->names);
 398 }
 399
 400 static char *
 401 buildnames(const struct dbm_page *page)
 402 {
 403         char    *buf;
 404         size_t   i, sz;
 405
 406         sz = lstlen(page->name, 2) + 1 + lstlen(page->sect, 2) +
 407             (page->arch == NULL ? 0 : 1 + lstlen(page->arch, 2)) + 2;
 408         buf = mandoc_malloc(sz);
 409         i = 0;
 410         lstcat(buf, &i, page->name, ", ");
 411         buf[i++] = '(';
 412         lstcat(buf, &i, page->sect, ", ");
 413         if (page->arch != NULL) {
 414                 buf[i++] = '/';
 415                 lstcat(buf, &i, page->arch, ", ");
 416         }
 417         buf[i++] = ')';
 418         buf[i++] = '\0';
 419         assert(i == sz);
 420         return buf;
 421 }
 422
 423 /*
 424  * Count the buffer space needed to print the NUL-terminated
 425  * list of NUL-terminated strings, when printing sep separator
 426  * characters between strings.
 427  */
 428 static size_t
 429 lstlen(const char *cp, size_t sep)
 430 {
 431         size_t   sz;
 432
 433         for (sz = 0;; sz++) {
 434                 if (cp[0] == '\0') {
 435                         if (cp[1] == '\0')
 436                                 break;
 437                         sz += sep - 1;
 438                 } else if (cp[0] < ' ')
 439                         sz--;
 440                 cp++;
 441         }
 442         return sz;
 443 }
 444
 445 /*
 446  * Print the NUL-terminated list of NUL-terminated strings
 447  * into the buffer, seperating strings with sep.
 448  */
 449 static void
 450 lstcat(char *buf, size_t *i, const char *cp, const char *sep)
 451 {
 452         const char *s;
 453
 454         for (;;) {
 455                 if (cp[0] == '\0') {
 456                         if (cp[1] == '\0')
 457                                 break;
 458                         s = sep;
 459                         while (*s != '\0')
 460                                 buf[(*i)++] = *s++;
 461                 } else if (cp[0] >= ' ')
 462                         buf[(*i)++] = cp[0];
 463                 cp++;
 464         }
 465 }
 466
 467 /*
 468  * Return 1 if the string *want occurs in any of the strings
 469  * in the NUL-terminated string list *have, or 0 otherwise.
 470  * If either argument is NULL or empty, assume no filtering
 471  * is desired and return 1.
 472  */
 473 static int
 474 lstmatch(const char *want, const char *have)
 475 {
 476         if (want == NULL || have == NULL || *have == '\0')
 477                 return 1;
 478         while (*have != '\0') {
 479                 if (strcasestr(have, want) != NULL)
 480                         return 1;
 481                 have = strchr(have, '\0') + 1;
 482         }
 483         return 0;
 484 }
 485
 486 /*
 487  * Build a list of values taken by the macro im in the manual page.
 488  */
 489 static char *
 490 buildoutput(size_t im, struct dbm_page *page)
 491 {
 492         const char      *oldoutput, *sep, *input;
 493         char            *output, *newoutput, *value;
 494         size_t           sz, i;
 495
 496         switch (im) {
 497         case KEY_Nd:
 498                 return mandoc_strdup(page->desc);
 499         case KEY_Nm:
 500                 input = page->name;
 501                 break;
 502         case KEY_sec:
 503                 input = page->sect;
 504                 break;
 505         case KEY_arch:
 506                 input = page->arch;
 507                 if (input == NULL)
 508                         input = "all\0";
 509                 break;
 510         default:
 511                 input = NULL;
 512                 break;
 513         }
 514
 515         if (input != NULL) {
 516                 sz = lstlen(input, 3) + 1;
 517                 output = mandoc_malloc(sz);
 518                 i = 0;
 519                 lstcat(output, &i, input, " # ");
 520                 output[i++] = '\0';
 521                 assert(i == sz);
 522                 return output;
 523         }
 524
 525         output = NULL;
 526         dbm_macro_bypage(im - 2, page->addr);
 527         while ((value = dbm_macro_next()) != NULL) {
 528                 if (output == NULL) {
 529                         oldoutput = "";
 530                         sep = "";
 531                 } else {
 532                         oldoutput = output;
 533                         sep = " # ";
 534                 }
 535                 mandoc_asprintf(&newoutput, "%s%s%s", oldoutput, sep, value);
 536                 free(output);
 537                 output = newoutput;
 538         }
 539         return output;
 540 }
 541
 542 /*
 543  * Compile a set of string tokens into an expression.
 544  * Tokens in "argv" are assumed to be individual expression atoms (e.g.,
 545  * "(", "foo=bar", etc.).
 546  */
 547 static struct expr *
 548 exprcomp(const struct mansearch *search, int argc, char *argv[], int *argi)
 549 {
 550         struct expr     *parent, *child;
 551         int              needterm, nested;
 552
 553         if ((nested = *argi) == argc)
 554                 return NULL;
 555         needterm = 1;
 556         parent = child = NULL;
 557         while (*argi < argc) {
 558                 if (strcmp(")", argv[*argi]) == 0) {
 559                         if (needterm)
 560                                 warnx("missing term "
 561                                     "before closing parenthesis");
 562                         needterm = 0;
 563                         if (nested)
 564                                 break;
 565                         warnx("ignoring unmatched right parenthesis");
 566                         ++*argi;
 567                         continue;
 568                 }
 569                 if (strcmp("-o", argv[*argi]) == 0) {
 570                         if (needterm) {
 571                                 if (*argi > 0)
 572                                         warnx("ignoring -o after %s",
 573                                             argv[*argi - 1]);
 574                                 else
 575                                         warnx("ignoring initial -o");
 576                         }
 577                         needterm = 1;
 578                         ++*argi;
 579                         continue;
 580                 }
 581                 needterm = 0;
 582                 if (child == NULL) {
 583                         child = expr_and(search, argc, argv, argi);
 584                         continue;
 585                 }
 586                 if (parent == NULL) {
 587                         parent = mandoc_calloc(1, sizeof(*parent));
 588                         parent->type = EXPR_OR;
 589                         parent->next = NULL;
 590                         parent->child = child;
 591                 }
 592                 child->next = expr_and(search, argc, argv, argi);
 593                 child = child->next;
 594         }
 595         if (needterm && *argi)
 596                 warnx("ignoring trailing %s", argv[*argi - 1]);
 597         return parent == NULL ? child : parent;
 598 }
 599
 600 static struct expr *
 601 expr_and(const struct mansearch *search, int argc, char *argv[], int *argi)
 602 {
 603         struct expr     *parent, *child;
 604         int              needterm;
 605
 606         needterm = 1;
 607         parent = child = NULL;
 608         while (*argi < argc) {
 609                 if (strcmp(")", argv[*argi]) == 0) {
 610                         if (needterm)
 611                                 warnx("missing term "
 612                                     "before closing parenthesis");
 613                         needterm = 0;
 614                         break;
 615                 }
 616                 if (strcmp("-o", argv[*argi]) == 0)
 617                         break;
 618                 if (strcmp("-a", argv[*argi]) == 0) {
 619                         if (needterm) {
 620                                 if (*argi > 0)
 621                                         warnx("ignoring -a after %s",
 622                                             argv[*argi - 1]);
 623                                 else
 624                                         warnx("ignoring initial -a");
 625                         }
 626                         needterm = 1;
 627                         ++*argi;
 628                         continue;
 629                 }
 630                 if (needterm == 0)
 631                         break;
 632                 if (child == NULL) {
 633                         child = exprterm(search, argc, argv, argi);
 634                         if (child != NULL)
 635                                 needterm = 0;
 636                         continue;
 637                 }
 638                 needterm = 0;
 639                 if (parent == NULL) {
 640                         parent = mandoc_calloc(1, sizeof(*parent));
 641                         parent->type = EXPR_AND;
 642                         parent->next = NULL;
 643                         parent->child = child;
 644                 }
 645                 child->next = exprterm(search, argc, argv, argi);
 646                 if (child->next != NULL) {
 647                         child = child->next;
 648                         needterm = 0;
 649                 }
 650         }
 651         if (needterm && *argi)
 652                 warnx("ignoring trailing %s", argv[*argi - 1]);
 653         return parent == NULL ? child : parent;
 654 }
 655
 656 static struct expr *
 657 exprterm(const struct mansearch *search, int argc, char *argv[], int *argi)
 658 {
 659         char             errbuf[BUFSIZ];
 660         struct expr     *e;
 661         char            *key, *val;
 662         uint64_t         iterbit;
 663         int              cs, i, irc;
 664
 665         if (strcmp("(", argv[*argi]) == 0) {
 666                 ++*argi;
 667                 e = exprcomp(search, argc, argv, argi);
 668                 if (*argi < argc) {
 669                         assert(strcmp(")", argv[*argi]) == 0);
 670                         ++*argi;
 671                 } else
 672                         warnx("unclosed parenthesis");
 673                 return e;
 674         }
 675
 676         if (strcmp("-i", argv[*argi]) == 0 && *argi + 1 < argc) {
 677                 cs = 0;
 678                 ++*argi;
 679         } else
 680                 cs = 1;
 681
 682         e = mandoc_calloc(1, sizeof(*e));
 683         e->type = EXPR_TERM;
 684         e->bits = 0;
 685         e->next = NULL;
 686         e->child = NULL;
 687
 688         if (search->argmode == ARG_NAME) {
 689                 e->bits = TYPE_Nm;
 690                 e->match.type = DBM_EXACT;
 691                 e->match.str = argv[(*argi)++];
 692                 return e;
 693         }
 694
 695         /*
 696          * Separate macro keys from search string.
 697          * If needed, request regular expression handling.
 698          */
 699
 700         if (search->argmode == ARG_WORD) {
 701                 e->bits = TYPE_Nm;
 702                 e->match.type = DBM_REGEX;
 703 #if HAVE_REWB_BSD
 704                 mandoc_asprintf(&val, "[[:<:]]%s[[:>:]]", argv[*argi]);
 705 #elif HAVE_REWB_SYSV
 706                 mandoc_asprintf(&val, "\\<%s\\>", argv[*argi]);
 707 #else
 708                 mandoc_asprintf(&val,
 709                     "(^|[^a-zA-Z01-9_])%s([^a-zA-Z01-9_]|$)", argv[*argi]);
 710 #endif
 711                 cs = 0;
 712         } else if ((val = strpbrk(argv[*argi], "=~")) == NULL) {
 713                 e->bits = TYPE_Nm | TYPE_Nd;
 714                 e->match.type = DBM_SUB;
 715                 e->match.str = argv[*argi];
 716         } else {
 717                 if (val == argv[*argi])
 718                         e->bits = TYPE_Nm | TYPE_Nd;
 719                 if (*val == '=') {
 720                         e->match.type = DBM_SUB;
 721                         e->match.str = val + 1;
 722                 } else
 723                         e->match.type = DBM_REGEX;
 724                 *val++ = '\0';
 725                 if (strstr(argv[*argi], "arch") != NULL)
 726                         cs = 0;
 727         }
 728
 729         /* Compile regular expressions. */
 730
 731         if (e->match.type == DBM_REGEX) {
 732                 e->match.re = mandoc_malloc(sizeof(*e->match.re));
 733                 irc = regcomp(e->match.re, val,
 734                     REG_EXTENDED | REG_NOSUB | (cs ? 0 : REG_ICASE));
 735                 if (irc) {
 736                         regerror(irc, e->match.re, errbuf, sizeof(errbuf));
 737                         warnx("regcomp /%s/: %s", val, errbuf);
 738                 }
 739                 if (search->argmode == ARG_WORD)
 740                         free(val);
 741                 if (irc) {
 742                         free(e->match.re);
 743                         free(e);
 744                         ++*argi;
 745                         return NULL;
 746                 }
 747         }
 748
 749         if (e->bits) {
 750                 ++*argi;
 751                 return e;
 752         }
 753
 754         /*
 755          * Parse out all possible fields.
 756          * If the field doesn't resolve, bail.
 757          */
 758
 759         while (NULL != (key = strsep(&argv[*argi], ","))) {
 760                 if ('\0' == *key)
 761                         continue;
 762                 for (i = 0, iterbit = 1; i < KEY_MAX; i++, iterbit <<= 1) {
 763                         if (0 == strcasecmp(key, mansearch_keynames[i])) {
 764                                 e->bits |= iterbit;
 765                                 break;
 766                         }
 767                 }
 768                 if (i == KEY_MAX) {
 769                         if (strcasecmp(key, "any"))
 770                                 warnx("treating unknown key "
 771                                     "\"%s\" as \"any\"", key);
 772                         e->bits |= ~0ULL;
 773                 }
 774         }
 775
 776         ++*argi;
 777         return e;
 778 }
 779
 780 static void
 781 exprfree(struct expr *e)
 782 {
 783         if (e->next != NULL)
 784                 exprfree(e->next);
 785         if (e->child != NULL)
 786                 exprfree(e->child);
 787         free(e);
 788 }