1 /*
   2  * Copyright (c) 2002 John Rochester
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer,
  10  *    in this position and unchanged.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. The name of the author may not be used to endorse or promote products
  15  *    derived from this software without specific prior written permission
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28 
  29 /*
  30  * Copyright 2012 Nexenta Systems, Inc. All rights reserved.
  31  * Copyright 2014 Garrett D'Amore <garrett@damore.org>
  32  */
  33 
  34 #include <sys/types.h>
  35 #include <sys/stat.h>
  36 #include <sys/param.h>
  37 
  38 #include <ctype.h>
  39 #include <dirent.h>
  40 #include <err.h>
  41 #include <signal.h>
  42 #include <stddef.h>
  43 #include <stdio.h>
  44 #include <stdlib.h>
  45 #include <string.h>
  46 #include <unistd.h>
  47 
  48 #include "man.h"
  49 #include "stringlist.h"
  50 
  51 
  52 /* Information collected about each man page in a section */
  53 struct page_info {
  54         char    *filename;
  55         char    *name;
  56         char    *suffix;
  57         ino_t   inode;
  58 };
  59 
  60 /* An expanding string */
  61 struct sbuf {
  62         char    *content;       /* the start of the buffer */
  63         char    *end;           /* just past the end of the content */
  64         char    *last;          /* the last allocated character */
  65 };
  66 
  67 /* Remove the last amount characters from the sbuf */
  68 #define sbuf_retract(sbuf, amount) ((sbuf)->end -= (amount))
  69 /* Return the length of the sbuf content */
  70 #define sbuf_length(sbuf) ((sbuf)->end - (sbuf)->content)
  71 
  72 typedef char *edited_copy(char *from, char *to, int length);
  73 
  74 /*
  75  * While the whatis line is being formed, it is stored in whatis_proto.
  76  * When finished, it is reformatted into whatis_final and then appended
  77  * to whatis_lines.
  78  */
  79 static struct sbuf      *whatis_proto;
  80 static struct sbuf      *whatis_final;
  81 static stringlist       *whatis_lines;  /* collected output lines */
  82 
  83 static char tempfile[MAXPATHLEN];       /* path of temporary file, if any */
  84 
  85 #define MDOC_COMMANDS   "ArDvErEvFlLiNmPa"
  86 
  87 
  88 /* Free a struct page_info and its content */
  89 static void
  90 free_page_info(struct page_info *info)
  91 {
  92 
  93         free(info->filename);
  94         free(info->name);
  95         free(info->suffix);
  96         free(info);
  97 }
  98 
  99 /*
 100  * Allocate and fill in a new struct page_info given the
 101  * name of the man section directory and the dirent of the file.
 102  * If the file is not a man page, return NULL.
 103  */
 104 static struct page_info *
 105 new_page_info(char *dir, struct dirent *dirent)
 106 {
 107         struct page_info *info;
 108         int             basename_length;
 109         char            *suffix;
 110         struct stat     st;
 111 
 112         if ((info = malloc(sizeof (struct page_info))) == NULL)
 113                 err(1, "malloc");
 114         basename_length = strlen(dirent->d_name);
 115         suffix = &dirent->d_name[basename_length];
 116         if (asprintf(&info->filename, "%s/%s", dir, dirent->d_name) == -1)
 117                 err(1, "asprintf");
 118         for (;;) {
 119                 if (--suffix == dirent->d_name || !isalnum(*suffix)) {
 120                         if (*suffix == '.')
 121                                 break;
 122                         free(info->filename);
 123                         free(info);
 124                         return (NULL);
 125                 }
 126         }
 127         *suffix++ = '\0';
 128         info->name = strdup(dirent->d_name);
 129         info->suffix = strdup(suffix);
 130         if (stat(info->filename, &st) < 0) {
 131                 warn("%s", info->filename);
 132                 free_page_info(info);
 133                 return (NULL);
 134         }
 135         if (!S_ISREG(st.st_mode)) {
 136                 free_page_info(info);
 137                 return (NULL);
 138         }
 139         info->inode = st.st_ino;
 140         return (info);
 141 }
 142 
 143 /*
 144  * Reset sbuf length to 0.
 145  */
 146 static void
 147 sbuf_clear(struct sbuf *sbuf)
 148 {
 149 
 150         sbuf->end = sbuf->content;
 151 }
 152 
 153 /*
 154  * Allocate a new sbuf.
 155  */
 156 static struct sbuf *
 157 new_sbuf(void)
 158 {
 159         struct sbuf     *sbuf;
 160 
 161         if ((sbuf = malloc(sizeof (struct sbuf))) == NULL)
 162                 err(1, "malloc");
 163         if ((sbuf->content = (char *)malloc(LINE_ALLOC)) == NULL)
 164                 err(1, "malloc");
 165         sbuf->last = sbuf->content + LINE_ALLOC - 1;
 166         sbuf_clear(sbuf);
 167 
 168         return (sbuf);
 169 }
 170 
 171 /*
 172  * Ensure that there is enough room in the sbuf
 173  * for nchars more characters.
 174  */
 175 static void
 176 sbuf_need(struct sbuf *sbuf, int nchars)
 177 {
 178         char *new_content;
 179         size_t size, cntsize;
 180         size_t grow = 128;
 181 
 182         while (grow < nchars) {
 183                 grow += 128;    /* we grow in chunks of 128 bytes */
 184         }
 185 
 186         /* Grow if the buffer isn't big enough */
 187         if (sbuf->end + nchars > sbuf->last) {
 188                 size = sbuf->last + 1 - sbuf->content;
 189                 size += grow;
 190                 cntsize = sbuf->end - sbuf->content;
 191 
 192                 if ((new_content = realloc(sbuf->content, size)) == NULL) {
 193                         perror("realloc");
 194                         if (tempfile[0] != '\0')
 195                                 (void) unlink(tempfile);
 196                         exit(1);
 197                 }
 198                 sbuf->content = new_content;
 199                 sbuf->end = new_content + cntsize;
 200                 sbuf->last = new_content + size - 1;
 201         }
 202 }
 203 
 204 /*
 205  * Append a string of a given length to the sbuf.
 206  */
 207 static void
 208 sbuf_append(struct sbuf *sbuf, const char *text, int length)
 209 {
 210         if (length > 0) {
 211                 sbuf_need(sbuf, length);
 212                 (void) memcpy(sbuf->end, text, length);
 213                 sbuf->end += length;
 214         }
 215 }
 216 
 217 /*
 218  * Append a null-terminated string to the sbuf.
 219  */
 220 static void
 221 sbuf_append_str(struct sbuf *sbuf, char *text)
 222 {
 223 
 224         sbuf_append(sbuf, text, strlen(text));
 225 }
 226 
 227 /*
 228  * Append an edited null-terminated string to the sbuf.
 229  */
 230 static void
 231 sbuf_append_edited(struct sbuf *sbuf, char *text, edited_copy copy)
 232 {
 233         int     length;
 234 
 235         if ((length = strlen(text)) > 0) {
 236                 sbuf_need(sbuf, length);
 237                 sbuf->end = copy(text, sbuf->end, length);
 238         }
 239 }
 240 
 241 /*
 242  * Strip any of a set of chars from the end of the sbuf.
 243  */
 244 static void
 245 sbuf_strip(struct sbuf *sbuf, const char *set)
 246 {
 247 
 248         while (sbuf->end > sbuf->content && strchr(set, sbuf->end[-1]) != NULL)
 249                 sbuf->end--;
 250 }
 251 
 252 /*
 253  * Return the null-terminated string built by the sbuf.
 254  */
 255 static char *
 256 sbuf_content(struct sbuf *sbuf)
 257 {
 258 
 259         *sbuf->end = '\0';
 260         return (sbuf->content);
 261 }
 262 
 263 /*
 264  * Return true if no man page exists in the directory with
 265  * any of the names in the stringlist.
 266  */
 267 static int
 268 no_page_exists(char *dir, stringlist *names, char *suffix)
 269 {
 270         char    path[MAXPATHLEN];
 271         char    *suffixes[] = { "", ".gz", ".bz2", NULL };
 272         size_t  i;
 273         int     j;
 274 
 275         for (i = 0; i < names->sl_cur; i++) {
 276                 for (j = 0; suffixes[j] != NULL; j++) {
 277                         (void) snprintf(path, MAXPATHLEN, "%s/%s.%s%s",
 278                             dir, names->sl_str[i], suffix, suffixes[j]);
 279                         if (access(path, F_OK) == 0) {
 280                                 return (0);
 281                         }
 282                 }
 283         }
 284         return (1);
 285 }
 286 
 287 /* ARGSUSED sig */
 288 static void
 289 trap_signal(int sig)
 290 {
 291 
 292         if (tempfile[0] != '\0')
 293                 (void) unlink(tempfile);
 294 
 295         exit(1);
 296 }
 297 
 298 /*
 299  * Attempt to open an output file.
 300  * Return NULL if unsuccessful.
 301  */
 302 static FILE *
 303 open_output(char *name)
 304 {
 305         FILE    *output;
 306 
 307         whatis_lines = sl_init();
 308         (void) snprintf(tempfile, MAXPATHLEN, "%s.tmp", name);
 309         name = tempfile;
 310         if ((output = fopen(name, "w")) == NULL) {
 311                 warn("%s", name);
 312                 return (NULL);
 313         }
 314         return (output);
 315 }
 316 
 317 static int
 318 linesort(const void *a, const void *b)
 319 {
 320 
 321         return (strcmp((*(const char * const *)a), (*(const char * const *)b)));
 322 }
 323 
 324 /*
 325  * Write the unique sorted lines to the output file.
 326  */
 327 static void
 328 finish_output(FILE *output, char *name)
 329 {
 330         size_t  i;
 331         char    *prev = NULL;
 332 
 333         qsort(whatis_lines->sl_str, whatis_lines->sl_cur, sizeof (char *),
 334             linesort);
 335         for (i = 0; i < whatis_lines->sl_cur; i++) {
 336                 char *line = whatis_lines->sl_str[i];
 337                 if (i > 0 && strcmp(line, prev) == 0)
 338                         continue;
 339                 prev = line;
 340                 (void) fputs(line, output);
 341                 (void) putc('\n', output);
 342         }
 343         (void) fclose(output);
 344         sl_free(whatis_lines, 1);
 345         (void) rename(tempfile, name);
 346         (void) unlink(tempfile);
 347 }
 348 
 349 static FILE *
 350 open_whatis(char *mandir)
 351 {
 352         char    filename[MAXPATHLEN];
 353 
 354         (void) snprintf(filename, MAXPATHLEN, "%s/%s", mandir, WHATIS);
 355         return (open_output(filename));
 356 }
 357 
 358 static void
 359 finish_whatis(FILE *output, char *mandir)
 360 {
 361         char    filename[MAXPATHLEN];
 362 
 363         (void) snprintf(filename, MAXPATHLEN, "%s/%s", mandir, WHATIS);
 364         finish_output(output, filename);
 365 }
 366 
 367 /*
 368  * Remove trailing spaces from a string, returning a pointer to just
 369  * beyond the new last character.
 370  */
 371 static char *
 372 trim_rhs(char *str)
 373 {
 374         char    *rhs;
 375 
 376         rhs = &str[strlen(str)];
 377         while (--rhs > str && isspace(*rhs))
 378                 ;
 379         *++rhs = '\0';
 380         return (rhs);
 381 }
 382 
 383 /*
 384  * Return a pointer to the next non-space character in the string.
 385  */
 386 static char *
 387 skip_spaces(char *s)
 388 {
 389 
 390         while (*s != '\0' && isspace(*s))
 391                 s++;
 392 
 393         return (s);
 394 }
 395 
 396 /*
 397  * Return whether the line is of one of the forms:
 398  *      .Sh NAME
 399  *      .Sh "NAME"
 400  *      etc.
 401  * assuming that section_start is ".Sh".
 402  */
 403 static int
 404 name_section_line(char *line, const char *section_start)
 405 {
 406         char            *rhs;
 407 
 408         if (strncmp(line, section_start, 3) != 0)
 409                 return (0);
 410         line = skip_spaces(line + 3);
 411         rhs = trim_rhs(line);
 412         if (*line == '"') {
 413                 line++;
 414                 if (*--rhs == '"')
 415                         *rhs = '\0';
 416         }
 417         if (strcmp(line, "NAME") == 0)
 418                 return (1);
 419 
 420         return (0);
 421 }
 422 
 423 /*
 424  * Copy characters while removing the most common nroff/troff markup:
 425  *      \(em, \(mi, \s[+-N], \&
 426  *      \fF, \f(fo, \f[font]
 427  *      \*s, \*(st, \*[stringvar]
 428  */
 429 static char *
 430 de_nroff_copy(char *from, char *to, int fromlen)
 431 {
 432         char    *from_end = &from[fromlen];
 433 
 434         while (from < from_end) {
 435                 switch (*from) {
 436                 case '\\':
 437                         switch (*++from) {
 438                         case '(':
 439                                 if (strncmp(&from[1], "em", 2) == 0 ||
 440                                     strncmp(&from[1], "mi", 2) == 0) {
 441                                         from += 3;
 442                                         continue;
 443                                 }
 444                                 break;
 445                         case 's':
 446                                 if (*++from == '-')
 447                                         from++;
 448                                 while (isdigit(*from))
 449                                         from++;
 450                                 continue;
 451                         case 'f':
 452                         case '*':
 453                                 if (*++from == '(') {
 454                                         from += 3;
 455                                 } else if (*from == '[') {
 456                                         while (*++from != ']' &&
 457                                             from < from_end)
 458                                                 ;
 459                                         from++;
 460                                 } else {
 461                                         from++;
 462                                 }
 463                                 continue;
 464                         case '&':
 465                                 from++;
 466                                 continue;
 467                         }
 468                         break;
 469                 }
 470                 *to++ = *from++;
 471         }
 472         return (to);
 473 }
 474 
 475 /*
 476  * Append a string with the nroff formatting removed.
 477  */
 478 static void
 479 add_nroff(char *text)
 480 {
 481 
 482         sbuf_append_edited(whatis_proto, text, de_nroff_copy);
 483 }
 484 
 485 /*
 486  * Appends "name(suffix), " to whatis_final
 487  */
 488 static void
 489 add_whatis_name(char *name, char *suffix)
 490 {
 491 
 492         if (*name != '\0') {
 493                 sbuf_append_str(whatis_final, name);
 494                 sbuf_append(whatis_final, "(", 1);
 495                 sbuf_append_str(whatis_final, suffix);
 496                 sbuf_append(whatis_final, "), ", 3);
 497         }
 498 }
 499 
 500 /*
 501  * Processes an old-style man(7) line. This ignores commands with only
 502  * a single number argument.
 503  */
 504 static void
 505 process_man_line(char *line)
 506 {
 507         char    *p;
 508 
 509         if (*line == '.') {
 510                 while (isalpha(*++line))
 511                         ;
 512                 p = line = skip_spaces(line);
 513                 while (*p != '\0') {
 514                         if (!isdigit(*p))
 515                                 break;
 516                         p++;
 517                 }
 518                 if (*p == '\0')
 519                         return;
 520         } else
 521                 line = skip_spaces(line);
 522         if (*line != '\0') {
 523                 add_nroff(line);
 524                 sbuf_append(whatis_proto, " ", 1);
 525         }
 526 }
 527 
 528 /*
 529  * Processes a new-style mdoc(7) line.
 530  */
 531 static void
 532 process_mdoc_line(char *line)
 533 {
 534         int     xref;
 535         int     arg = 0;
 536         char    *line_end = &line[strlen(line)];
 537         int     orig_length = sbuf_length(whatis_proto);
 538         char    *next;
 539 
 540         if (*line == '\0')
 541                 return;
 542         if (line[0] != '.' || !isupper(line[1]) || !islower(line[2])) {
 543                 add_nroff(skip_spaces(line));
 544                 sbuf_append(whatis_proto, " ", 1);
 545                 return;
 546         }
 547         xref = strncmp(line, ".Xr", 3) == 0;
 548         line += 3;
 549         while ((line = skip_spaces(line)) < line_end) {
 550                 if (*line == '"') {
 551                         next = ++line;
 552                         for (;;) {
 553                                 next = strchr(next, '"');
 554                                 if (next == NULL)
 555                                         break;
 556                                 (void) memmove(next, next + 1, strlen(next));
 557                                 line_end--;
 558                                 if (*next != '"')
 559                                         break;
 560                                 next++;
 561                         }
 562                 } else {
 563                         next = strpbrk(line, " \t");
 564                 }
 565                 if (next != NULL)
 566                         *next++ = '\0';
 567                 else
 568                         next = line_end;
 569                 if (isupper(*line) && islower(line[1]) && line[2] == '\0') {
 570                         if (strcmp(line, "Ns") == 0) {
 571                                 arg = 0;
 572                                 line = next;
 573                                 continue;
 574                         }
 575                         if (strstr(line, MDOC_COMMANDS) != NULL) {
 576                                 line = next;
 577                                 continue;
 578                         }
 579                 }
 580                 if (arg > 0 && strchr(",.:;?!)]", *line) == 0) {
 581                         if (xref) {
 582                                 sbuf_append(whatis_proto, "(", 1);
 583                                 add_nroff(line);
 584                                 sbuf_append(whatis_proto, ")", 1);
 585                                 xref = 0;
 586                         } else {
 587                                 sbuf_append(whatis_proto, " ", 1);
 588                         }
 589                 }
 590                 add_nroff(line);
 591                 arg++;
 592                 line = next;
 593         }
 594         if (sbuf_length(whatis_proto) > orig_length)
 595                 sbuf_append(whatis_proto, " ", 1);
 596 }
 597 
 598 /*
 599  * Collect a list of comma-separated names from the text.
 600  */
 601 static void
 602 collect_names(stringlist *names, char *text)
 603 {
 604         char    *arg;
 605 
 606         for (;;) {
 607                 arg = text;
 608                 text = strchr(text, ',');
 609                 if (text != NULL)
 610                         *text++ = '\0';
 611                 (void) sl_add(names, arg);
 612                 if (text == NULL)
 613                         return;
 614                 if (*text == ' ')
 615                         text++;
 616         }
 617 }
 618 
 619 enum { STATE_UNKNOWN, STATE_MANSTYLE, STATE_MDOCNAME, STATE_MDOCDESC };
 620 
 621 /*
 622  * Process a man page source into a single whatis line and add it
 623  * to whatis_lines.
 624  */
 625 static void
 626 process_page(struct page_info *page, char *section_dir)
 627 {
 628         FILE            *fp;
 629         stringlist      *names;
 630         char            *descr;
 631         int             state = STATE_UNKNOWN;
 632         size_t          i;
 633         char            *line = NULL;
 634         size_t          linecap = 0;
 635 
 636         sbuf_clear(whatis_proto);
 637         if ((fp = fopen(page->filename, "r")) == NULL) {
 638                 warn("%s", page->filename);
 639                 return;
 640         }
 641         while (getline(&line, &linecap, fp) > 0) {
 642                 /* Skip comments */
 643                 if (strncmp(line, ".\\\"", 3) == 0)
 644                         continue;
 645                 switch (state) {
 646                 /* Haven't reached the NAME section yet */
 647                 case STATE_UNKNOWN:
 648                         if (name_section_line(line, ".SH"))
 649                                 state = STATE_MANSTYLE;
 650                         else if (name_section_line(line, ".Sh"))
 651                                 state = STATE_MDOCNAME;
 652                         continue;
 653                 /* Inside an old-style .SH NAME section */
 654                 case STATE_MANSTYLE:
 655                         if (strncmp(line, ".SH", 3) == 0 ||
 656                             strncmp(line, ".SS", 3) == 0)
 657                                 break;
 658                         (void) trim_rhs(line);
 659                         if (strcmp(line, ".") == 0)
 660                                 continue;
 661                         if (strncmp(line, ".IX", 3) == 0) {
 662                                 line += 3;
 663                                 line = skip_spaces(line);
 664                         }
 665                         process_man_line(line);
 666                         continue;
 667                 /* Inside a new-style .Sh NAME section (the .Nm part) */
 668                 case STATE_MDOCNAME:
 669                         (void) trim_rhs(line);
 670                         if (strncmp(line, ".Nm", 3) == 0) {
 671                                 process_mdoc_line(line);
 672                                 continue;
 673                         } else {
 674                                 if (strcmp(line, ".") == 0)
 675                                         continue;
 676                                 sbuf_append(whatis_proto, "- ", 2);
 677                                 state = STATE_MDOCDESC;
 678                         }
 679                         /* FALLTHROUGH */
 680                 /* Inside a new-style .Sh NAME section (after the .Nm-s) */
 681                 case STATE_MDOCDESC:
 682                         if (strncmp(line, ".Sh", 3) == 0)
 683                                 break;
 684                         (void) trim_rhs(line);
 685                         if (strcmp(line, ".") == 0)
 686                                 continue;
 687                         process_mdoc_line(line);
 688                         continue;
 689                 }
 690                 break;
 691         }
 692         (void) fclose(fp);
 693         sbuf_strip(whatis_proto, " \t.-");
 694         line = sbuf_content(whatis_proto);
 695         /*
 696          * Line now contains the appropriate data, but without the
 697          * proper indentation or the section appended to each name.
 698          */
 699         descr = strstr(line, " - ");
 700         if (descr == NULL) {
 701                 descr = strchr(line, ' ');
 702                 if (descr == NULL)
 703                         return;
 704                 *descr++ = '\0';
 705         } else {
 706                 *descr = '\0';
 707                 descr += 3;
 708         }
 709         names = sl_init();
 710         collect_names(names, line);
 711         sbuf_clear(whatis_final);
 712         if (!sl_find(names, page->name) &&
 713             no_page_exists(section_dir, names, page->suffix)) {
 714                 /*
 715                  * Add the page name since that's the only
 716                  * thing that man(1) will find.
 717                  */
 718                 add_whatis_name(page->name, page->suffix);
 719         }
 720         for (i = 0; i < names->sl_cur; i++)
 721                 add_whatis_name(names->sl_str[i], page->suffix);
 722         sl_free(names, 0);
 723         /* Remove last ", " */
 724         sbuf_retract(whatis_final, 2);
 725         while (sbuf_length(whatis_final) < INDENT)
 726                 sbuf_append(whatis_final, " ", 1);
 727         sbuf_append(whatis_final, " - ", 3);
 728         sbuf_append_str(whatis_final, skip_spaces(descr));
 729         (void) sl_add(whatis_lines, strdup(sbuf_content(whatis_final)));
 730 }
 731 
 732 /*
 733  * Sort pages first by inode number, then by name.
 734  */
 735 static int
 736 pagesort(const void *a, const void *b)
 737 {
 738         const struct page_info *p1 = *(struct page_info * const *) a;
 739         const struct page_info *p2 = *(struct page_info * const *) b;
 740 
 741         if (p1->inode == p2->inode)
 742                 return (strcmp(p1->name, p2->name));
 743 
 744         return (p1->inode - p2->inode);
 745 }
 746 
 747 /*
 748  * Process a single man section.
 749  */
 750 static void
 751 process_section(char *section_dir)
 752 {
 753         struct dirent   **entries;
 754         int             nentries;
 755         struct page_info **pages;
 756         int             npages = 0;
 757         int             i;
 758         ino_t           prev_inode = 0;
 759 
 760         /* Scan the man section directory for pages */
 761         nentries = scandir(section_dir, &entries, NULL, alphasort);
 762 
 763         /* Collect information about man pages */
 764         pages = (struct page_info **)calloc(nentries,
 765             sizeof (struct page_info *));
 766         for (i = 0; i < nentries; i++) {
 767                 struct page_info *info = new_page_info(section_dir, entries[i]);
 768                 if (info != NULL)
 769                         pages[npages++] = info;
 770                 free(entries[i]);
 771         }
 772         free(entries);
 773         qsort(pages, npages, sizeof (struct page_info *), pagesort);
 774 
 775         /* Process each unique page */
 776         for (i = 0; i < npages; i++) {
 777                 struct page_info *page = pages[i];
 778                 if (page->inode != prev_inode) {
 779                         prev_inode = page->inode;
 780                         process_page(page, section_dir);
 781                 }
 782                 free_page_info(page);
 783         }
 784         free(pages);
 785 }
 786 
 787 /*
 788  * Return whether the directory entry is a man page section.
 789  */
 790 static int
 791 select_sections(const struct dirent *entry)
 792 {
 793         const char      *p = &entry->d_name[3];
 794 
 795         if (strncmp(entry->d_name, "man", 3) != 0)
 796                 return (0);
 797         while (*p != '\0') {
 798                 if (!isalnum(*p++))
 799                         return (0);
 800         }
 801         return (1);
 802 }
 803 
 804 /*
 805  * Process a single top-level man directory by finding all the
 806  * sub-directories named man* and processing each one in turn.
 807  */
 808 void
 809 mwpath(char *path)
 810 {
 811         FILE            *fp = NULL;
 812         struct dirent   **entries;
 813         int             nsections;
 814         int             i;
 815 
 816         (void) signal(SIGINT, trap_signal);
 817         (void) signal(SIGHUP, trap_signal);
 818         (void) signal(SIGQUIT, trap_signal);
 819         (void) signal(SIGTERM, trap_signal);
 820 
 821         whatis_proto = new_sbuf();
 822         whatis_final = new_sbuf();
 823 
 824         nsections = scandir(path, &entries, select_sections, alphasort);
 825         if ((fp = open_whatis(path)) == NULL)
 826                 return;
 827         for (i = 0; i < nsections; i++) {
 828                 char    section_dir[MAXPATHLEN];
 829 
 830                 (void) snprintf(section_dir, MAXPATHLEN, "%s/%s",
 831                     path, entries[i]->d_name);
 832                 process_section(section_dir);
 833                 free(entries[i]);
 834         }
 835         free(entries);
 836         finish_whatis(fp, path);
 837 }