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