dir.c

   1 /*
   2  * This handles recursive filename detection with exclude
   3  * files, index knowledge etc..
   4  *
   5  * Copyright (C) Linus Torvalds, 2005-2006
   6  *               Junio Hamano, 2005-2006
   7  */
   8 #include "cache.h"
   9 #include "dir.h"
  10 #include "refs.h"
  11
  12 struct path_simplify {
  13         int len;
  14         const char *path;
  15 };
  16
  17 static int read_directory_recursive(struct dir_struct *dir,
  18         const char *path, const char *base, int baselen,
  19         int check_only, const struct path_simplify *simplify);
  20 static int get_dtype(struct dirent *de, const char *path);
  21
  22 int common_prefix(const char **pathspec)
  23 {
  24         const char *path, *slash, *next;
  25         int prefix;
  26
  27         if (!pathspec)
  28                 return 0;
  29
  30         path = *pathspec;
  31         slash = strrchr(path, '/');
  32         if (!slash)
  33                 return 0;
  34
  35         prefix = slash - path + 1;
  36         while ((next = *++pathspec) != NULL) {
  37                 int len = strlen(next);
  38                 if (len >= prefix && !memcmp(path, next, prefix))
  39                         continue;
  40                 len = prefix - 1;
  41                 for (;;) {
  42                         if (!len)
  43                                 return 0;
  44                         if (next[--len] != '/')
  45                                 continue;
  46                         if (memcmp(path, next, len+1))
  47                                 continue;
  48                         prefix = len + 1;
  49                         break;
  50                 }
  51         }
  52         return prefix;
  53 }
  54
  55 /*
  56  * Does 'match' match the given name?
  57  * A match is found if
  58  *
  59  * (1) the 'match' string is leading directory of 'name', or
  60  * (2) the 'match' string is a wildcard and matches 'name', or
  61  * (3) the 'match' string is exactly the same as 'name'.
  62  *
  63  * and the return value tells which case it was.
  64  *
  65  * It returns 0 when there is no match.
  66  */
  67 static int match_one(const char *match, const char *name, int namelen)
  68 {
  69         int matchlen;
  70
  71         /* If the match was just the prefix, we matched */
  72         if (!*match)
  73                 return MATCHED_RECURSIVELY;
  74
  75         for (;;) {
  76                 unsigned char c1 = *match;
  77                 unsigned char c2 = *name;
  78                 if (c1 == '\0' || is_glob_special(c1))
  79                         break;
  80                 if (c1 != c2)
  81                         return 0;
  82                 match++;
  83                 name++;
  84                 namelen--;
  85         }
  86
  87
  88         /*
  89          * If we don't match the matchstring exactly,
  90          * we need to match by fnmatch
  91          */
  92         matchlen = strlen(match);
  93         if (strncmp(match, name, matchlen))
  94                 return !fnmatch(match, name, 0) ? MATCHED_FNMATCH : 0;
  95
  96         if (namelen == matchlen)
  97                 return MATCHED_EXACTLY;
  98         if (match[matchlen-1] == '/' || name[matchlen] == '/')
  99                 return MATCHED_RECURSIVELY;
 100         return 0;
 101 }
 102
 103 /*
 104  * Given a name and a list of pathspecs, see if the name matches
 105  * any of the pathspecs.  The caller is also interested in seeing
 106  * all pathspec matches some names it calls this function with
 107  * (otherwise the user could have mistyped the unmatched pathspec),
 108  * and a mark is left in seen[] array for pathspec element that
 109  * actually matched anything.
 110  */
 111 int match_pathspec(const char **pathspec, const char *name, int namelen,
 112                 int prefix, char *seen)
 113 {
 114         int i, retval = 0;
 115
 116         if (!pathspec)
 117                 return 1;
 118
 119         name += prefix;
 120         namelen -= prefix;
 121
 122         for (i = 0; pathspec[i] != NULL; i++) {
 123                 int how;
 124                 const char *match = pathspec[i] + prefix;
 125                 if (seen && seen[i] == MATCHED_EXACTLY)
 126                         continue;
 127                 how = match_one(match, name, namelen);
 128                 if (how) {
 129                         if (retval < how)
 130                                 retval = how;
 131                         if (seen && seen[i] < how)
 132                                 seen[i] = how;
 133                 }
 134         }
 135         return retval;
 136 }
 137
 138 static int no_wildcard(const char *string)
 139 {
 140         return string[strcspn(string, "*?[{\\")] == '\0';
 141 }
 142
 143 void add_exclude(const char *string, const char *base,
 144                  int baselen, struct exclude_list *which)
 145 {
 146         struct exclude *x;
 147         size_t len;
 148         int to_exclude = 1;
 149         int flags = 0;
 150
 151         if (*string == '!') {
 152                 to_exclude = 0;
 153                 string++;
 154         }
 155         len = strlen(string);
 156         if (len && string[len - 1] == '/') {
 157                 char *s;
 158                 x = xmalloc(sizeof(*x) + len);
 159                 s = (char *)(x+1);
 160                 memcpy(s, string, len - 1);
 161                 s[len - 1] = '\0';
 162                 string = s;
 163                 x->pattern = s;
 164                 flags = EXC_FLAG_MUSTBEDIR;
 165         } else {
 166                 x = xmalloc(sizeof(*x));
 167                 x->pattern = string;
 168         }
 169         x->to_exclude = to_exclude;
 170         x->patternlen = strlen(string);
 171         x->base = base;
 172         x->baselen = baselen;
 173         x->flags = flags;
 174         if (!strchr(string, '/'))
 175                 x->flags |= EXC_FLAG_NODIR;
 176         if (no_wildcard(string))
 177                 x->flags |= EXC_FLAG_NOWILDCARD;
 178         if (*string == '*' && no_wildcard(string+1))
 179                 x->flags |= EXC_FLAG_ENDSWITH;
 180         ALLOC_GROW(which->excludes, which->nr + 1, which->alloc);
 181         which->excludes[which->nr++] = x;
 182 }
 183
 184 static int add_excludes_from_file_1(const char *fname,
 185                                     const char *base,
 186                                     int baselen,
 187                                     char **buf_p,
 188                                     struct exclude_list *which)
 189 {
 190         struct stat st;
 191         int fd, i;
 192         size_t size;
 193         char *buf, *entry;
 194
 195         fd = open(fname, O_RDONLY);
 196         if (fd < 0 || fstat(fd, &st) < 0)
 197                 goto err;
 198         size = xsize_t(st.st_size);
 199         if (size == 0) {
 200                 close(fd);
 201                 return 0;
 202         }
 203         buf = xmalloc(size+1);
 204         if (read_in_full(fd, buf, size) != size)
 205         {
 206                 free(buf);
 207                 goto err;
 208         }
 209         close(fd);
 210
 211         if (buf_p)
 212                 *buf_p = buf;
 213         buf[size++] = '\n';
 214         entry = buf;
 215         for (i = 0; i < size; i++) {
 216                 if (buf[i] == '\n') {
 217                         if (entry != buf + i && entry[0] != '#') {
 218                                 buf[i - (i && buf[i-1] == '\r')] = 0;
 219                                 add_exclude(entry, base, baselen, which);
 220                         }
 221                         entry = buf + i + 1;
 222                 }
 223         }
 224         return 0;
 225
 226  err:
 227         if (0 <= fd)
 228                 close(fd);
 229         return -1;
 230 }
 231
 232 void add_excludes_from_file(struct dir_struct *dir, const char *fname)
 233 {
 234         if (add_excludes_from_file_1(fname, "", 0, NULL,
 235                                      &dir->exclude_list[EXC_FILE]) < 0)
 236                 die("cannot use %s as an exclude file", fname);
 237 }
 238
 239 static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
 240 {
 241         struct exclude_list *el;
 242         struct exclude_stack *stk = NULL;
 243         int current;
 244
 245         if ((!dir->exclude_per_dir) ||
 246             (baselen + strlen(dir->exclude_per_dir) >= PATH_MAX))
 247                 return; /* too long a path -- ignore */
 248
 249         /* Pop the ones that are not the prefix of the path being checked. */
 250         el = &dir->exclude_list[EXC_DIRS];
 251         while ((stk = dir->exclude_stack) != NULL) {
 252                 if (stk->baselen <= baselen &&
 253                     !strncmp(dir->basebuf, base, stk->baselen))
 254                         break;
 255                 dir->exclude_stack = stk->prev;
 256                 while (stk->exclude_ix < el->nr)
 257                         free(el->excludes[--el->nr]);
 258                 free(stk->filebuf);
 259                 free(stk);
 260         }
 261
 262         /* Read from the parent directories and push them down. */
 263         current = stk ? stk->baselen : -1;
 264         while (current < baselen) {
 265                 struct exclude_stack *stk = xcalloc(1, sizeof(*stk));
 266                 const char *cp;
 267
 268                 if (current < 0) {
 269                         cp = base;
 270                         current = 0;
 271                 }
 272                 else {
 273                         cp = strchr(base + current + 1, '/');
 274                         if (!cp)
 275                                 die("oops in prep_exclude");
 276                         cp++;
 277                 }
 278                 stk->prev = dir->exclude_stack;
 279                 stk->baselen = cp - base;
 280                 stk->exclude_ix = el->nr;
 281                 memcpy(dir->basebuf + current, base + current,
 282                        stk->baselen - current);
 283                 strcpy(dir->basebuf + stk->baselen, dir->exclude_per_dir);
 284                 add_excludes_from_file_1(dir->basebuf,
 285                                          dir->basebuf, stk->baselen,
 286                                          &stk->filebuf, el);
 287                 dir->exclude_stack = stk;
 288                 current = stk->baselen;
 289         }
 290         dir->basebuf[baselen] = '\0';
 291 }
 292
 293 /* Scan the list and let the last match determine the fate.
 294  * Return 1 for exclude, 0 for include and -1 for undecided.
 295  */
 296 static int excluded_1(const char *pathname,
 297                       int pathlen, const char *basename, int *dtype,
 298                       struct exclude_list *el)
 299 {
 300         int i;
 301
 302         if (el->nr) {
 303                 for (i = el->nr - 1; 0 <= i; i--) {
 304                         struct exclude *x = el->excludes[i];
 305                         const char *exclude = x->pattern;
 306                         int to_exclude = x->to_exclude;
 307
 308                         if (x->flags & EXC_FLAG_MUSTBEDIR) {
 309                                 if (*dtype == DT_UNKNOWN)
 310                                         *dtype = get_dtype(NULL, pathname);
 311                                 if (*dtype != DT_DIR)
 312                                         continue;
 313                         }
 314
 315                         if (x->flags & EXC_FLAG_NODIR) {
 316                                 /* match basename */
 317                                 if (x->flags & EXC_FLAG_NOWILDCARD) {
 318                                         if (!strcmp(exclude, basename))
 319                                                 return to_exclude;
 320                                 } else if (x->flags & EXC_FLAG_ENDSWITH) {
 321                                         if (x->patternlen - 1 <= pathlen &&
 322                                             !strcmp(exclude + 1, pathname + pathlen - x->patternlen + 1))
 323                                                 return to_exclude;
 324                                 } else {
 325                                         if (fnmatch(exclude, basename, 0) == 0)
 326                                                 return to_exclude;
 327                                 }
 328                         }
 329                         else {
 330                                 /* match with FNM_PATHNAME:
 331                                  * exclude has base (baselen long) implicitly
 332                                  * in front of it.
 333                                  */
 334                                 int baselen = x->baselen;
 335                                 if (*exclude == '/')
 336                                         exclude++;
 337
 338                                 if (pathlen < baselen ||
 339                                     (baselen && pathname[baselen-1] != '/') ||
 340                                     strncmp(pathname, x->base, baselen))
 341                                     continue;
 342
 343                                 if (x->flags & EXC_FLAG_NOWILDCARD) {
 344                                         if (!strcmp(exclude, pathname + baselen))
 345                                                 return to_exclude;
 346                                 } else {
 347                                         if (fnmatch(exclude, pathname+baselen,
 348                                                     FNM_PATHNAME) == 0)
 349                                             return to_exclude;
 350                                 }
 351                         }
 352                 }
 353         }
 354         return -1; /* undecided */
 355 }
 356
 357 int excluded(struct dir_struct *dir, const char *pathname, int *dtype_p)
 358 {
 359         int pathlen = strlen(pathname);
 360         int st;
 361         const char *basename = strrchr(pathname, '/');
 362         basename = (basename) ? basename+1 : pathname;
 363
 364         prep_exclude(dir, pathname, basename-pathname);
 365         for (st = EXC_CMDL; st <= EXC_FILE; st++) {
 366                 switch (excluded_1(pathname, pathlen, basename,
 367                                    dtype_p, &dir->exclude_list[st])) {
 368                 case 0:
 369                         return 0;
 370                 case 1:
 371                         return 1;
 372                 }
 373         }
 374         return 0;
 375 }
 376
 377 static struct dir_entry *dir_entry_new(const char *pathname, int len)
 378 {
 379         struct dir_entry *ent;
 380
 381         ent = xmalloc(sizeof(*ent) + len + 1);
 382         ent->len = len;
 383         memcpy(ent->name, pathname, len);
 384         ent->name[len] = 0;
 385         return ent;
 386 }
 387
 388 static struct dir_entry *dir_add_name(struct dir_struct *dir, const char *pathname, int len)
 389 {
 390         if (cache_name_exists(pathname, len, ignore_case))
 391                 return NULL;
 392
 393         ALLOC_GROW(dir->entries, dir->nr+1, dir->alloc);
 394         return dir->entries[dir->nr++] = dir_entry_new(pathname, len);
 395 }
 396
 397 static struct dir_entry *dir_add_ignored(struct dir_struct *dir, const char *pathname, int len)
 398 {
 399         if (cache_name_pos(pathname, len) >= 0)
 400                 return NULL;
 401
 402         ALLOC_GROW(dir->ignored, dir->ignored_nr+1, dir->ignored_alloc);
 403         return dir->ignored[dir->ignored_nr++] = dir_entry_new(pathname, len);
 404 }
 405
 406 enum exist_status {
 407         index_nonexistent = 0,
 408         index_directory,
 409         index_gitdir,
 410 };
 411
 412 /*
 413  * The index sorts alphabetically by entry name, which
 414  * means that a gitlink sorts as '\0' at the end, while
 415  * a directory (which is defined not as an entry, but as
 416  * the files it contains) will sort with the '/' at the
 417  * end.
 418  */
 419 static enum exist_status directory_exists_in_index(const char *dirname, int len)
 420 {
 421         int pos = cache_name_pos(dirname, len);
 422         if (pos < 0)
 423                 pos = -pos-1;
 424         while (pos < active_nr) {
 425                 struct cache_entry *ce = active_cache[pos++];
 426                 unsigned char endchar;
 427
 428                 if (strncmp(ce->name, dirname, len))
 429                         break;
 430                 endchar = ce->name[len];
 431                 if (endchar > '/')
 432                         break;
 433                 if (endchar == '/')
 434                         return index_directory;
 435                 if (!endchar && S_ISGITLINK(ce->ce_mode))
 436                         return index_gitdir;
 437         }
 438         return index_nonexistent;
 439 }
 440
 441 /*
 442  * When we find a directory when traversing the filesystem, we
 443  * have three distinct cases:
 444  *
 445  *  - ignore it
 446  *  - see it as a directory
 447  *  - recurse into it
 448  *
 449  * and which one we choose depends on a combination of existing
 450  * git index contents and the flags passed into the directory
 451  * traversal routine.
 452  *
 453  * Case 1: If we *already* have entries in the index under that
 454  * directory name, we always recurse into the directory to see
 455  * all the files.
 456  *
 457  * Case 2: If we *already* have that directory name as a gitlink,
 458  * we always continue to see it as a gitlink, regardless of whether
 459  * there is an actual git directory there or not (it might not
 460  * be checked out as a subproject!)
 461  *
 462  * Case 3: if we didn't have it in the index previously, we
 463  * have a few sub-cases:
 464  *
 465  *  (a) if "show_other_directories" is true, we show it as
 466  *      just a directory, unless "hide_empty_directories" is
 467  *      also true and the directory is empty, in which case
 468  *      we just ignore it entirely.
 469  *  (b) if it looks like a git directory, and we don't have
 470  *      'no_gitlinks' set we treat it as a gitlink, and show it
 471  *      as a directory.
 472  *  (c) otherwise, we recurse into it.
 473  */
 474 enum directory_treatment {
 475         show_directory,
 476         ignore_directory,
 477         recurse_into_directory,
 478 };
 479
 480 static enum directory_treatment treat_directory(struct dir_struct *dir,
 481         const char *dirname, int len,
 482         const struct path_simplify *simplify)
 483 {
 484         /* The "len-1" is to strip the final '/' */
 485         switch (directory_exists_in_index(dirname, len-1)) {
 486         case index_directory:
 487                 return recurse_into_directory;
 488
 489         case index_gitdir:
 490                 if (dir->flags & DIR_SHOW_OTHER_DIRECTORIES)
 491                         return ignore_directory;
 492                 return show_directory;
 493
 494         case index_nonexistent:
 495                 if (dir->flags & DIR_SHOW_OTHER_DIRECTORIES)
 496                         break;
 497                 if (!(dir->flags & DIR_NO_GITLINKS)) {
 498                         unsigned char sha1[20];
 499                         if (resolve_gitlink_ref(dirname, "HEAD", sha1) == 0)
 500                                 return show_directory;
 501                 }
 502                 return recurse_into_directory;
 503         }
 504
 505         /* This is the "show_other_directories" case */
 506         if (!(dir->flags & DIR_HIDE_EMPTY_DIRECTORIES))
 507                 return show_directory;
 508         if (!read_directory_recursive(dir, dirname, dirname, len, 1, simplify))
 509                 return ignore_directory;
 510         return show_directory;
 511 }
 512
 513 /*
 514  * This is an inexact early pruning of any recursive directory
 515  * reading - if the path cannot possibly be in the pathspec,
 516  * return true, and we'll skip it early.
 517  */
 518 static int simplify_away(const char *path, int pathlen, const struct path_simplify *simplify)
 519 {
 520         if (simplify) {
 521                 for (;;) {
 522                         const char *match = simplify->path;
 523                         int len = simplify->len;
 524
 525                         if (!match)
 526                                 break;
 527                         if (len > pathlen)
 528                                 len = pathlen;
 529                         if (!memcmp(path, match, len))
 530                                 return 0;
 531                         simplify++;
 532                 }
 533                 return 1;
 534         }
 535         return 0;
 536 }
 537
 538 static int in_pathspec(const char *path, int len, const struct path_simplify *simplify)
 539 {
 540         if (simplify) {
 541                 for (; simplify->path; simplify++) {
 542                         if (len == simplify->len
 543                             && !memcmp(path, simplify->path, len))
 544                                 return 1;
 545                 }
 546         }
 547         return 0;
 548 }
 549
 550 static int get_dtype(struct dirent *de, const char *path)
 551 {
 552         int dtype = de ? DTYPE(de) : DT_UNKNOWN;
 553         struct stat st;
 554
 555         if (dtype != DT_UNKNOWN)
 556                 return dtype;
 557         if (lstat(path, &st))
 558                 return dtype;
 559         if (S_ISREG(st.st_mode))
 560                 return DT_REG;
 561         if (S_ISDIR(st.st_mode))
 562                 return DT_DIR;
 563         if (S_ISLNK(st.st_mode))
 564                 return DT_LNK;
 565         return dtype;
 566 }
 567
 568 /*
 569  * Read a directory tree. We currently ignore anything but
 570  * directories, regular files and symlinks. That's because git
 571  * doesn't handle them at all yet. Maybe that will change some
 572  * day.
 573  *
 574  * Also, we ignore the name ".git" (even if it is not a directory).
 575  * That likely will not change.
 576  */
 577 static int read_directory_recursive(struct dir_struct *dir, const char *path, const char *base, int baselen, int check_only, const struct path_simplify *simplify)
 578 {
 579         DIR *fdir = opendir(*path ? path : ".");
 580         int contents = 0;
 581
 582         if (fdir) {
 583                 struct dirent *de;
 584                 char fullname[PATH_MAX + 1];
 585                 memcpy(fullname, base, baselen);
 586
 587                 while ((de = readdir(fdir)) != NULL) {
 588                         int len, dtype;
 589                         int exclude;
 590
 591                         if (is_dot_or_dotdot(de->d_name) ||
 592                              !strcmp(de->d_name, ".git"))
 593                                 continue;
 594                         len = strlen(de->d_name);
 595                         /* Ignore overly long pathnames! */
 596                         if (len + baselen + 8 > sizeof(fullname))
 597                                 continue;
 598                         memcpy(fullname + baselen, de->d_name, len+1);
 599                         if (simplify_away(fullname, baselen + len, simplify))
 600                                 continue;
 601
 602                         dtype = DTYPE(de);
 603                         exclude = excluded(dir, fullname, &dtype);
 604                         if (exclude && (dir->flags & DIR_COLLECT_IGNORED)
 605                             && ((dir->flags & DIR_COLLECT_ALL_IGNORED) || in_pathspec(fullname, baselen + len, simplify)))
 606                         {
 607                                 if (dir->flags & DIR_COLLECT_ALL_IGNORED)
 608                                 {
 609                                         // collect dirs too, but end their names with a /
 610                                         if (dtype == DT_UNKNOWN)
 611                                                 dtype = get_dtype(de, fullname);
 612
 613                                         if (dtype == DT_DIR)
 614                                         {
 615                                                 memcpy(fullname + baselen + len, "/", 2);
 616                                                 dir_add_ignored(dir, fullname, baselen + len+1);
 617                                                 fullname[baselen + len] = 0;
 618                                         }
 619                                         else
 620                                         {
 621                                                 dir_add_ignored(dir, fullname, baselen + len);
 622                                         }
 623                                 }
 624                                 else
 625                                 {
 626                                         dir_add_ignored(dir, fullname, baselen + len);
 627                                 }
 628                         }
 629
 630                         /*
 631                          * Excluded? If we don't explicitly want to show
 632                          * ignored files, ignore it
 633                          */
 634                         if (exclude && !(dir->flags & DIR_SHOW_IGNORED))
 635                                 continue;
 636
 637                         if (dtype == DT_UNKNOWN)
 638                                 dtype = get_dtype(de, fullname);
 639
 640                         /*
 641                          * Do we want to see just the ignored files?
 642                          * We still need to recurse into directories,
 643                          * even if we don't ignore them, since the
 644                          * directory may contain files that we do..
 645                          */
 646                         if (!exclude && (dir->flags & DIR_SHOW_IGNORED)) {
 647                                 if (dtype != DT_DIR)
 648                                         continue;
 649                         }
 650
 651                         switch (dtype) {
 652                         default:
 653                                 continue;
 654                         case DT_DIR:
 655                                 memcpy(fullname + baselen + len, "/", 2);
 656                                 len++;
 657                                 switch (treat_directory(dir, fullname, baselen + len, simplify)) {
 658                                 case show_directory:
 659                                         if (exclude != !!(dir->flags
 660                                                         & DIR_SHOW_IGNORED))
 661                                                 continue;
 662                                         break;
 663                                 case recurse_into_directory:
 664                                         if (dir->flags & DIR_COLLECT_DIRECTORIES)
 665                                                 dir_add_name(dir, fullname, baselen + len);
 666                                         if (dir->flags & DIR_NO_RECURSE_READDIR)
 667                                                 continue;
 668                                         contents += read_directory_recursive(dir,
 669                                                 fullname, fullname, baselen + len, 0, simplify);
 670                                         continue;
 671                                 case ignore_directory:
 672                                         if (dir->flags & DIR_COLLECT_DIRECTORIES)
 673                                                 dir_add_name(dir, fullname, baselen + len);
 674                                         continue;
 675                                 }
 676                                 break;
 677                         case DT_REG:
 678                         case DT_LNK:
 679                                 break;
 680                         }
 681                         contents++;
 682                         if (check_only)
 683                                 goto exit_early;
 684                         else
 685                                 dir_add_name(dir, fullname, baselen + len);
 686                 }
 687 exit_early:
 688                 closedir(fdir);
 689         }
 690
 691         return contents;
 692 }
 693
 694 static int cmp_name(const void *p1, const void *p2)
 695 {
 696         const struct dir_entry *e1 = *(const struct dir_entry **)p1;
 697         const struct dir_entry *e2 = *(const struct dir_entry **)p2;
 698
 699         return cache_name_compare(e1->name, e1->len,
 700                                   e2->name, e2->len);
 701 }
 702
 703 /*
 704  * Return the length of the "simple" part of a path match limiter.
 705  */
 706 static int simple_length(const char *match)
 707 {
 708         int len = -1;
 709
 710         for (;;) {
 711                 unsigned char c = *match++;
 712                 len++;
 713                 if (c == '\0' || is_glob_special(c))
 714                         return len;
 715         }
 716 }
 717
 718 static struct path_simplify *create_simplify(const char **pathspec)
 719 {
 720         int nr, alloc = 0;
 721         struct path_simplify *simplify = NULL;
 722
 723         if (!pathspec)
 724                 return NULL;
 725
 726         for (nr = 0 ; ; nr++) {
 727                 const char *match;
 728                 if (nr >= alloc) {
 729                         alloc = alloc_nr(alloc);
 730                         simplify = xrealloc(simplify, alloc * sizeof(*simplify));
 731                 }
 732                 match = *pathspec++;
 733                 if (!match)
 734                         break;
 735                 simplify[nr].path = match;
 736                 simplify[nr].len = simple_length(match);
 737         }
 738         simplify[nr].path = NULL;
 739         simplify[nr].len = 0;
 740         return simplify;
 741 }
 742
 743 static void free_simplify(struct path_simplify *simplify)
 744 {
 745         free(simplify);
 746 }
 747
 748 int read_directory(struct dir_struct *dir, const char *path, const char *base, int baselen, const char **pathspec)
 749 {
 750         struct path_simplify *simplify;
 751
 752         if (has_symlink_leading_path(path, strlen(path)))
 753                 return dir->nr;
 754
 755         simplify = create_simplify(pathspec);
 756         read_directory_recursive(dir, path, base, baselen, 0, simplify);
 757         free_simplify(simplify);
 758         qsort(dir->entries, dir->nr, sizeof(struct dir_entry *), cmp_name);
 759         qsort(dir->ignored, dir->ignored_nr, sizeof(struct dir_entry *), cmp_name);
 760         return dir->nr;
 761 }
 762
 763 int file_exists(const char *f)
 764 {
 765         struct stat sb;
 766         return lstat(f, &sb) == 0;
 767 }
 768
 769 /*
 770  * get_relative_cwd() gets the prefix of the current working directory
 771  * relative to 'dir'.  If we are not inside 'dir', it returns NULL.
 772  *
 773  * As a convenience, it also returns NULL if 'dir' is already NULL.  The
 774  * reason for this behaviour is that it is natural for functions returning
 775  * directory names to return NULL to say "this directory does not exist"
 776  * or "this directory is invalid".  These cases are usually handled the
 777  * same as if the cwd is not inside 'dir' at all, so get_relative_cwd()
 778  * returns NULL for both of them.
 779  *
 780  * Most notably, get_relative_cwd(buffer, size, get_git_work_tree())
 781  * unifies the handling of "outside work tree" with "no work tree at all".
 782  */
 783 char *get_relative_cwd(char *buffer, int size, const char *dir)
 784 {
 785         char *cwd = buffer;
 786
 787         if (!dir)
 788                 return NULL;
 789         if (!getcwd(buffer, size))
 790                 die("can't find the current directory: %s", strerror(errno));
 791
 792         if (!is_absolute_path(dir))
 793                 dir = make_absolute_path(dir);
 794
 795         while (*dir && *dir == *cwd) {
 796                 dir++;
 797                 cwd++;
 798         }
 799         if (*dir)
 800                 return NULL;
 801         if (*cwd == '/')
 802                 return cwd + 1;
 803         return cwd;
 804 }
 805
 806 int is_inside_dir(const char *dir)
 807 {
 808         char buffer[PATH_MAX];
 809         return get_relative_cwd(buffer, sizeof(buffer), dir) != NULL;
 810 }
 811
 812 int is_empty_dir(const char *path)
 813 {
 814         DIR *dir = opendir(path);
 815         struct dirent *e;
 816         int ret = 1;
 817
 818         if (!dir)
 819                 return 0;
 820
 821         while ((e = readdir(dir)) != NULL)
 822                 if (!is_dot_or_dotdot(e->d_name)) {
 823                         ret = 0;
 824                         break;
 825                 }
 826
 827         closedir(dir);
 828         return ret;
 829 }
 830
 831 int remove_dir_recursively(struct strbuf *path, int only_empty)
 832 {
 833         DIR *dir = opendir(path->buf);
 834         struct dirent *e;
 835         int ret = 0, original_len = path->len, len;
 836
 837         if (!dir)
 838                 return -1;
 839         if (path->buf[original_len - 1] != '/')
 840                 strbuf_addch(path, '/');
 841
 842         len = path->len;
 843         while ((e = readdir(dir)) != NULL) {
 844                 struct stat st;
 845                 if (is_dot_or_dotdot(e->d_name))
 846                         continue;
 847
 848                 strbuf_setlen(path, len);
 849                 strbuf_addstr(path, e->d_name);
 850                 if (lstat(path->buf, &st))
 851                         ; /* fall thru */
 852                 else if (S_ISDIR(st.st_mode)) {
 853                         if (!remove_dir_recursively(path, only_empty))
 854                                 continue; /* happy */
 855                 } else if (!only_empty && !unlink(path->buf))
 856                         continue; /* happy, too */
 857
 858                 /* path too long, stat fails, or non-directory still exists */
 859                 ret = -1;
 860                 break;
 861         }
 862         closedir(dir);
 863
 864         strbuf_setlen(path, original_len);
 865         if (!ret)
 866                 ret = rmdir(path->buf);
 867         return ret;
 868 }
 869
 870 void setup_standard_excludes(struct dir_struct *dir)
 871 {
 872         const char *path;
 873
 874         dir->exclude_per_dir = ".gitignore";
 875         path = git_path("info/exclude");
 876         if (!access(path, R_OK))
 877                 add_excludes_from_file(dir, path);
 878         if (excludes_file && !access(excludes_file, R_OK))
 879                 add_excludes_from_file(dir, excludes_file);
 880 }
 881
 882 int remove_path(const char *name)
 883 {
 884         char *slash;
 885
 886         if (unlink(name) && errno != ENOENT)
 887                 return -1;
 888
 889         slash = strrchr(name, '/');
 890         if (slash) {
 891                 char *dirs = xstrdup(name);
 892                 slash = dirs + (slash - name);
 893                 do {
 894                         *slash = '\0';
 895                 } while (rmdir(dirs) && (slash = strrchr(dirs, '/')));
 896                 free(dirs);
 897         }
 898         return 0;
 899 }
 900