1 /*- 2 * Copyright (c) 1990, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #if defined(LIBC_SCCS) && !defined(lint) 9 static char sccsid[] = "@(#)fts.c 8.4 (Berkeley) 04/16/94"; 10 #endif /* LIBC_SCCS and not lint */ 11 12 #include <sys/param.h> 13 #include <sys/stat.h> 14 15 #include <dirent.h> 16 #include <errno.h> 17 #include <fcntl.h> 18 #include <fts.h> 19 #include <stdlib.h> 20 #include <string.h> 21 #include <unistd.h> 22 23 static FTSENT *fts_alloc __P((FTS *, char *, int)); 24 static FTSENT *fts_build __P((FTS *, int)); 25 static void fts_lfree __P((FTSENT *)); 26 static void fts_load __P((FTS *, FTSENT *)); 27 static size_t fts_maxarglen __P((char * const *)); 28 static void fts_padjust __P((FTS *, void *)); 29 static int fts_palloc __P((FTS *, size_t)); 30 static FTSENT *fts_sort __P((FTS *, FTSENT *, int)); 31 static u_short fts_stat __P((FTS *, FTSENT *, int)); 32 33 #define ISDOT(a) (a[0] == '.' && (!a[1] || a[1] == '.' && !a[2])) 34 35 #define ISSET(opt) (sp->fts_options & opt) 36 #define SET(opt) (sp->fts_options |= opt) 37 38 #define CHDIR(sp, path) (!ISSET(FTS_NOCHDIR) && chdir(path)) 39 #define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd)) 40 41 /* fts_build flags */ 42 #define BCHILD 1 /* fts_children */ 43 #define BNAMES 2 /* fts_children, names only */ 44 #define BREAD 3 /* fts_read */ 45 46 FTS * 47 fts_open(argv, options, compar) 48 char * const *argv; 49 register int options; 50 int (*compar)(); 51 { 52 register FTS *sp; 53 register FTSENT *p, *root; 54 register int nitems; 55 FTSENT *parent, *tmp; 56 int len; 57 58 /* Options check. */ 59 if (options & ~FTS_OPTIONMASK) { 60 errno = EINVAL; 61 return (NULL); 62 } 63 64 /* Allocate/initialize the stream */ 65 if ((sp = malloc((u_int)sizeof(FTS))) == NULL) 66 return (NULL); 67 memset(sp, 0, sizeof(FTS)); 68 sp->fts_compar = compar; 69 sp->fts_options = options; 70 71 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */ 72 if (ISSET(FTS_LOGICAL)) 73 SET(FTS_NOCHDIR); 74 75 /* 76 * Start out with 1K of path space, and enough, in any case, 77 * to hold the user's paths. 78 */ 79 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN))) 80 goto mem1; 81 82 /* Allocate/initialize root's parent. */ 83 if ((parent = fts_alloc(sp, "", 0)) == NULL) 84 goto mem2; 85 parent->fts_level = FTS_ROOTPARENTLEVEL; 86 87 /* Allocate/initialize root(s). */ 88 for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) { 89 /* Don't allow zero-length paths. */ 90 if ((len = strlen(*argv)) == 0) { 91 errno = ENOENT; 92 goto mem3; 93 } 94 95 p = fts_alloc(sp, *argv, len); 96 p->fts_level = FTS_ROOTLEVEL; 97 p->fts_parent = parent; 98 p->fts_accpath = p->fts_name; 99 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW)); 100 101 /* Command-line "." and ".." are real directories. */ 102 if (p->fts_info == FTS_DOT) 103 p->fts_info = FTS_D; 104 105 /* 106 * If comparison routine supplied, traverse in sorted 107 * order; otherwise traverse in the order specified. 108 */ 109 if (compar) { 110 p->fts_link = root; 111 root = p; 112 } else { 113 p->fts_link = NULL; 114 if (root == NULL) 115 tmp = root = p; 116 else { 117 tmp->fts_link = p; 118 tmp = p; 119 } 120 } 121 } 122 if (compar && nitems > 1) 123 root = fts_sort(sp, root, nitems); 124 125 /* 126 * Allocate a dummy pointer and make fts_read think that we've just 127 * finished the node before the root(s); set p->fts_info to FTS_INIT 128 * so that everything about the "current" node is ignored. 129 */ 130 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL) 131 goto mem3; 132 sp->fts_cur->fts_link = root; 133 sp->fts_cur->fts_info = FTS_INIT; 134 135 /* 136 * If using chdir(2), grab a file descriptor pointing to dot to insure 137 * that we can get back here; this could be avoided for some paths, 138 * but almost certainly not worth the effort. Slashes, symbolic links, 139 * and ".." are all fairly nasty problems. Note, if we can't get the 140 * descriptor we run anyway, just more slowly. 141 */ 142 if (!ISSET(FTS_NOCHDIR) && (sp->fts_rfd = open(".", O_RDONLY, 0)) < 0) 143 SET(FTS_NOCHDIR); 144 145 return (sp); 146 147 mem3: fts_lfree(root); 148 free(parent); 149 mem2: free(sp->fts_path); 150 mem1: free(sp); 151 return (NULL); 152 } 153 154 static void 155 fts_load(sp, p) 156 FTS *sp; 157 register FTSENT *p; 158 { 159 register int len; 160 register char *cp; 161 162 /* 163 * Load the stream structure for the next traversal. Since we don't 164 * actually enter the directory until after the preorder visit, set 165 * the fts_accpath field specially so the chdir gets done to the right 166 * place and the user can access the first node. From fts_open it's 167 * known that the path will fit. 168 */ 169 len = p->fts_pathlen = p->fts_namelen; 170 memmove(sp->fts_path, p->fts_name, len + 1); 171 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) { 172 len = strlen(++cp); 173 memmove(p->fts_name, cp, len + 1); 174 p->fts_namelen = len; 175 } 176 p->fts_accpath = p->fts_path = sp->fts_path; 177 sp->fts_dev = p->fts_dev; 178 } 179 180 int 181 fts_close(sp) 182 FTS *sp; 183 { 184 register FTSENT *freep, *p; 185 int saved_errno; 186 187 /* 188 * This still works if we haven't read anything -- the dummy structure 189 * points to the root list, so we step through to the end of the root 190 * list which has a valid parent pointer. 191 */ 192 if (sp->fts_cur) { 193 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 194 freep = p; 195 p = p->fts_link ? p->fts_link : p->fts_parent; 196 free(freep); 197 } 198 free(p); 199 } 200 201 /* Free up child linked list, sort array, path buffer. */ 202 if (sp->fts_child) 203 fts_lfree(sp->fts_child); 204 if (sp->fts_array) 205 free(sp->fts_array); 206 free(sp->fts_path); 207 208 /* Return to original directory, save errno if necessary. */ 209 if (!ISSET(FTS_NOCHDIR)) { 210 saved_errno = fchdir(sp->fts_rfd) ? errno : 0; 211 (void)close(sp->fts_rfd); 212 } 213 214 /* Free up the stream pointer. */ 215 free(sp); 216 217 /* Set errno and return. */ 218 if (!ISSET(FTS_NOCHDIR) && saved_errno) { 219 errno = saved_errno; 220 return (-1); 221 } 222 return (0); 223 } 224 225 /* 226 * Special case a root of "/" so that slashes aren't appended which would 227 * cause paths to be written as "//foo". 228 */ 229 #define NAPPEND(p) \ 230 (p->fts_level == FTS_ROOTLEVEL && p->fts_pathlen == 1 && \ 231 p->fts_path[0] == '/' ? 0 : p->fts_pathlen) 232 233 FTSENT * 234 fts_read(sp) 235 register FTS *sp; 236 { 237 register FTSENT *p, *tmp; 238 register int instr; 239 register char *t; 240 int saved_errno; 241 242 /* If finished or unrecoverable error, return NULL. */ 243 if (sp->fts_cur == NULL || ISSET(FTS_STOP)) 244 return (NULL); 245 246 /* Set current node pointer. */ 247 p = sp->fts_cur; 248 249 /* Save and zero out user instructions. */ 250 instr = p->fts_instr; 251 p->fts_instr = FTS_NOINSTR; 252 253 /* Any type of file may be re-visited; re-stat and re-turn. */ 254 if (instr == FTS_AGAIN) { 255 p->fts_info = fts_stat(sp, p, 0); 256 return (p); 257 } 258 259 /* 260 * Following a symlink -- SLNONE test allows application to see 261 * SLNONE and recover. If indirecting through a symlink, have 262 * keep a pointer to current location. If unable to get that 263 * pointer, follow fails. 264 */ 265 if (instr == FTS_FOLLOW && 266 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) { 267 p->fts_info = fts_stat(sp, p, 1); 268 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) 269 if ((p->fts_symfd = open(".", O_RDONLY, 0)) < 0) { 270 p->fts_errno = errno; 271 p->fts_info = FTS_ERR; 272 } else 273 p->fts_flags |= FTS_SYMFOLLOW; 274 return (p); 275 } 276 277 /* Directory in pre-order. */ 278 if (p->fts_info == FTS_D) { 279 /* If skipped or crossed mount point, do post-order visit. */ 280 if (instr == FTS_SKIP || 281 ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev) { 282 if (p->fts_flags & FTS_SYMFOLLOW) 283 (void)close(p->fts_symfd); 284 if (sp->fts_child) { 285 fts_lfree(sp->fts_child); 286 sp->fts_child = NULL; 287 } 288 p->fts_info = FTS_DP; 289 return (p); 290 } 291 292 /* Rebuild if only read the names and now traversing. */ 293 if (sp->fts_child && sp->fts_options & FTS_NAMEONLY) { 294 sp->fts_options &= ~FTS_NAMEONLY; 295 fts_lfree(sp->fts_child); 296 sp->fts_child = NULL; 297 } 298 299 /* 300 * Cd to the subdirectory. 301 * 302 * If have already read and now fail to chdir, whack the list 303 * to make the names come out right, and set the parent errno 304 * so the application will eventually get an error condition. 305 * Set the FTS_DONTCHDIR flag so that when we logically change 306 * directories back to the parent we don't do a chdir. 307 * 308 * If haven't read do so. If the read fails, fts_build sets 309 * FTS_STOP or the fts_info field of the node. 310 */ 311 if (sp->fts_child) { 312 if (CHDIR(sp, p->fts_accpath)) { 313 p->fts_errno = errno; 314 p->fts_flags |= FTS_DONTCHDIR; 315 for (p = sp->fts_child; p; p = p->fts_link) 316 p->fts_accpath = 317 p->fts_parent->fts_accpath; 318 } 319 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) { 320 if (ISSET(FTS_STOP)) 321 return (NULL); 322 return (p); 323 } 324 p = sp->fts_child; 325 sp->fts_child = NULL; 326 goto name; 327 } 328 329 /* Move to the next node on this level. */ 330 next: tmp = p; 331 if (p = p->fts_link) { 332 free(tmp); 333 334 /* 335 * If reached the top, return to the original directory, and 336 * load the paths for the next root. 337 */ 338 if (p->fts_level == FTS_ROOTLEVEL) { 339 if (!ISSET(FTS_NOCHDIR) && FCHDIR(sp, sp->fts_rfd)) { 340 SET(FTS_STOP); 341 return (NULL); 342 } 343 fts_load(sp, p); 344 return (sp->fts_cur = p); 345 } 346 347 /* 348 * User may have called fts_set on the node. If skipped, 349 * ignore. If followed, get a file descriptor so we can 350 * get back if necessary. 351 */ 352 if (p->fts_instr == FTS_SKIP) 353 goto next; 354 if (p->fts_instr == FTS_FOLLOW) { 355 p->fts_info = fts_stat(sp, p, 1); 356 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) 357 if ((p->fts_symfd = 358 open(".", O_RDONLY, 0)) < 0) { 359 p->fts_errno = errno; 360 p->fts_info = FTS_ERR; 361 } else 362 p->fts_flags |= FTS_SYMFOLLOW; 363 p->fts_instr = FTS_NOINSTR; 364 } 365 366 name: t = sp->fts_path + NAPPEND(p->fts_parent); 367 *t++ = '/'; 368 memmove(t, p->fts_name, p->fts_namelen + 1); 369 return (sp->fts_cur = p); 370 } 371 372 /* Move up to the parent node. */ 373 p = tmp->fts_parent; 374 free(tmp); 375 376 if (p->fts_level == FTS_ROOTPARENTLEVEL) { 377 /* 378 * Done; free everything up and set errno to 0 so the user 379 * can distinguish between error and EOF. 380 */ 381 free(p); 382 errno = 0; 383 return (sp->fts_cur = NULL); 384 } 385 386 /* Nul terminate the pathname. */ 387 sp->fts_path[p->fts_pathlen] = '\0'; 388 389 /* 390 * Return to the parent directory. If at a root node or came through 391 * a symlink, go back through the file descriptor. Otherwise, cd up 392 * one directory. 393 */ 394 if (p->fts_level == FTS_ROOTLEVEL) { 395 if (!ISSET(FTS_NOCHDIR) && FCHDIR(sp, sp->fts_rfd)) { 396 SET(FTS_STOP); 397 return (NULL); 398 } 399 } else if (p->fts_flags & FTS_SYMFOLLOW) { 400 if (FCHDIR(sp, p->fts_symfd)) { 401 saved_errno = errno; 402 (void)close(p->fts_symfd); 403 errno = saved_errno; 404 SET(FTS_STOP); 405 return (NULL); 406 } 407 (void)close(p->fts_symfd); 408 } else if (!(p->fts_flags & FTS_DONTCHDIR)) { 409 if (CHDIR(sp, "..")) { 410 SET(FTS_STOP); 411 return (NULL); 412 } 413 } 414 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP; 415 return (sp->fts_cur = p); 416 } 417 418 /* 419 * Fts_set takes the stream as an argument although it's not used in this 420 * implementation; it would be necessary if anyone wanted to add global 421 * semantics to fts using fts_set. An error return is allowed for similar 422 * reasons. 423 */ 424 /* ARGSUSED */ 425 int 426 fts_set(sp, p, instr) 427 FTS *sp; 428 FTSENT *p; 429 int instr; 430 { 431 if (instr && instr != FTS_AGAIN && instr != FTS_FOLLOW && 432 instr != FTS_NOINSTR && instr != FTS_SKIP) { 433 errno = EINVAL; 434 return (1); 435 } 436 p->fts_instr = instr; 437 return (0); 438 } 439 440 FTSENT * 441 fts_children(sp, instr) 442 register FTS *sp; 443 int instr; 444 { 445 register FTSENT *p; 446 int fd; 447 448 if (instr && instr != FTS_NAMEONLY) { 449 errno = EINVAL; 450 return (NULL); 451 } 452 453 /* Set current node pointer. */ 454 p = sp->fts_cur; 455 456 /* 457 * Errno set to 0 so user can distinguish empty directory from 458 * an error. 459 */ 460 errno = 0; 461 462 /* Fatal errors stop here. */ 463 if (ISSET(FTS_STOP)) 464 return (NULL); 465 466 /* Return logical hierarchy of user's arguments. */ 467 if (p->fts_info == FTS_INIT) 468 return (p->fts_link); 469 470 /* 471 * If not a directory being visited in pre-order, stop here. Could 472 * allow FTS_DNR, assuming the user has fixed the problem, but the 473 * same effect is available with FTS_AGAIN. 474 */ 475 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */) 476 return (NULL); 477 478 /* Free up any previous child list. */ 479 if (sp->fts_child) 480 fts_lfree(sp->fts_child); 481 482 if (instr == FTS_NAMEONLY) { 483 sp->fts_options |= FTS_NAMEONLY; 484 instr = BNAMES; 485 } else 486 instr = BCHILD; 487 488 /* 489 * If using chdir on a relative path and called BEFORE fts_read does 490 * its chdir to the root of a traversal, we can lose -- we need to 491 * chdir into the subdirectory, and we don't know where the current 492 * directory is, so we can't get back so that the upcoming chdir by 493 * fts_read will work. 494 */ 495 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' || 496 ISSET(FTS_NOCHDIR)) 497 return (sp->fts_child = fts_build(sp, instr)); 498 499 if ((fd = open(".", O_RDONLY, 0)) < 0) 500 return (NULL); 501 sp->fts_child = fts_build(sp, instr); 502 if (fchdir(fd)) 503 return (NULL); 504 (void)close(fd); 505 return (sp->fts_child); 506 } 507 508 /* 509 * This is the tricky part -- do not casually change *anything* in here. The 510 * idea is to build the linked list of entries that are used by fts_children 511 * and fts_read. There are lots of special cases. 512 * 513 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is 514 * set and it's a physical walk (so that symbolic links can't be directories), 515 * we can do things quickly. First, if it's a 4.4BSD file system, the type 516 * of the file is in the directory entry. Otherwise, we assume that the number 517 * of subdirectories in a node is equal to the number of links to the parent. 518 * The former skips all stat calls. The latter skips stat calls in any leaf 519 * directories and for any files after the subdirectories in the directory have 520 * been found, cutting the stat calls by about 2/3. 521 */ 522 static FTSENT * 523 fts_build(sp, type) 524 register FTS *sp; 525 int type; 526 { 527 register struct dirent *dp; 528 register FTSENT *p, *head; 529 register int nitems; 530 FTSENT *cur, *tail; 531 DIR *dirp; 532 void *adjaddr; 533 int cderrno, descend, len, level, maxlen, nlinks, saved_errno; 534 char *cp; 535 536 /* Set current node pointer. */ 537 cur = sp->fts_cur; 538 539 /* 540 * Open the directory for reading. If this fails, we're done. 541 * If being called from fts_read, set the fts_info field. 542 */ 543 if ((dirp = opendir(cur->fts_accpath)) == NULL) { 544 if (type == BREAD) { 545 cur->fts_info = FTS_DNR; 546 cur->fts_errno = errno; 547 } 548 return (NULL); 549 } 550 551 /* 552 * Nlinks is the number of possible entries of type directory in the 553 * directory if we're cheating on stat calls, 0 if we're not doing 554 * any stat calls at all, -1 if we're doing stats on everything. 555 */ 556 if (type == BNAMES) 557 nlinks = 0; 558 else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) 559 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 560 else 561 nlinks = -1; 562 563 #ifdef notdef 564 (void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink); 565 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 566 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 567 #endif 568 /* 569 * If we're going to need to stat anything or we want to descend 570 * and stay in the directory, chdir. If this fails we keep going, 571 * but set a flag so we don't chdir after the post-order visit. 572 * We won't be able to stat anything, but we can still return the 573 * names themselves. Note, that since fts_read won't be able to 574 * chdir into the directory, it will have to return different path 575 * names than before, i.e. "a/b" instead of "b". Since the node 576 * has already been visited in pre-order, have to wait until the 577 * post-order visit to return the error. There is a special case 578 * here, if there was nothing to stat then it's not an error to 579 * not be able to stat. This is all fairly nasty. If a program 580 * needed sorted entries or stat information, they had better be 581 * checking FTS_NS on the returned nodes. 582 */ 583 cderrno = 0; 584 if (nlinks || type == BREAD) 585 if (FCHDIR(sp, dirfd(dirp))) { 586 if (nlinks && type == BREAD) 587 cur->fts_errno = errno; 588 cur->fts_flags |= FTS_DONTCHDIR; 589 descend = 0; 590 cderrno = errno; 591 } else 592 descend = 1; 593 else 594 descend = 0; 595 596 /* 597 * Figure out the max file name length that can be stored in the 598 * current path -- the inner loop allocates more path as necessary. 599 * We really wouldn't have to do the maxlen calculations here, we 600 * could do them in fts_read before returning the path, but it's a 601 * lot easier here since the length is part of the dirent structure. 602 * 603 * If not changing directories set a pointer so that can just append 604 * each new name into the path. 605 */ 606 maxlen = sp->fts_pathlen - cur->fts_pathlen - 1; 607 len = NAPPEND(cur); 608 if (ISSET(FTS_NOCHDIR)) { 609 cp = sp->fts_path + len; 610 *cp++ = '/'; 611 } 612 613 level = cur->fts_level + 1; 614 615 /* Read the directory, attaching each entry to the `link' pointer. */ 616 adjaddr = NULL; 617 for (head = tail = NULL, nitems = 0; dp = readdir(dirp);) { 618 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 619 continue; 620 621 if ((p = fts_alloc(sp, dp->d_name, (int)dp->d_namlen)) == NULL) 622 goto mem1; 623 if (dp->d_namlen > maxlen) { 624 if (fts_palloc(sp, (size_t)dp->d_namlen)) { 625 /* 626 * No more memory for path or structures. Save 627 * errno, free up the current structure and the 628 * structures already allocated. 629 */ 630 mem1: saved_errno = errno; 631 if (p) 632 free(p); 633 fts_lfree(head); 634 (void)closedir(dirp); 635 errno = saved_errno; 636 cur->fts_info = FTS_ERR; 637 SET(FTS_STOP); 638 return (NULL); 639 } 640 adjaddr = sp->fts_path; 641 maxlen = sp->fts_pathlen - sp->fts_cur->fts_pathlen - 1; 642 } 643 644 p->fts_pathlen = len + dp->d_namlen + 1; 645 p->fts_parent = sp->fts_cur; 646 p->fts_level = level; 647 648 if (cderrno) { 649 if (nlinks) { 650 p->fts_info = FTS_NS; 651 p->fts_errno = cderrno; 652 } else 653 p->fts_info = FTS_NSOK; 654 p->fts_accpath = cur->fts_accpath; 655 } else if (nlinks == 0 656 #ifdef DT_DIR 657 || nlinks > 0 && 658 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN 659 #endif 660 ) { 661 p->fts_accpath = 662 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 663 p->fts_info = FTS_NSOK; 664 } else { 665 /* Build a file name for fts_stat to stat. */ 666 if (ISSET(FTS_NOCHDIR)) { 667 p->fts_accpath = p->fts_path; 668 memmove(cp, p->fts_name, p->fts_namelen + 1); 669 } else 670 p->fts_accpath = p->fts_name; 671 /* Stat it. */ 672 p->fts_info = fts_stat(sp, p, 0); 673 674 /* Decrement link count if applicable. */ 675 if (nlinks > 0 && (p->fts_info == FTS_D || 676 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 677 --nlinks; 678 } 679 680 /* We walk in directory order so "ls -f" doesn't get upset. */ 681 p->fts_link = NULL; 682 if (head == NULL) 683 head = tail = p; 684 else { 685 tail->fts_link = p; 686 tail = p; 687 } 688 ++nitems; 689 } 690 (void)closedir(dirp); 691 692 /* 693 * If had to realloc the path, adjust the addresses for the rest 694 * of the tree. 695 */ 696 if (adjaddr) 697 fts_padjust(sp, adjaddr); 698 699 /* 700 * If not changing directories, reset the path back to original 701 * state. 702 */ 703 if (ISSET(FTS_NOCHDIR)) { 704 if (cp - 1 > sp->fts_path) 705 --cp; 706 *cp = '\0'; 707 } 708 709 /* 710 * If descended after called from fts_children or after called from 711 * fts_read and nothing found, get back. At the root level we use 712 * the saved fd; if one of fts_open()'s arguments is a relative path 713 * to an empty directory, we wind up here with no other way back. If 714 * can't get back, we're done. 715 */ 716 if (descend && (type == BCHILD || !nitems) && 717 (cur->fts_level == FTS_ROOTLEVEL ? 718 FCHDIR(sp, sp->fts_rfd) : CHDIR(sp, ".."))) { 719 cur->fts_info = FTS_ERR; 720 SET(FTS_STOP); 721 return (NULL); 722 } 723 724 /* If didn't find anything, return NULL. */ 725 if (!nitems) { 726 if (type == BREAD) 727 cur->fts_info = FTS_DP; 728 return (NULL); 729 } 730 731 /* Sort the entries. */ 732 if (sp->fts_compar && nitems > 1) 733 head = fts_sort(sp, head, nitems); 734 return (head); 735 } 736 737 static u_short 738 fts_stat(sp, p, follow) 739 FTS *sp; 740 register FTSENT *p; 741 int follow; 742 { 743 register FTSENT *t; 744 register dev_t dev; 745 register ino_t ino; 746 struct stat *sbp, sb; 747 int saved_errno; 748 749 /* If user needs stat info, stat buffer already allocated. */ 750 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 751 752 /* 753 * If doing a logical walk, or application requested FTS_FOLLOW, do 754 * a stat(2). If that fails, check for a non-existent symlink. If 755 * fail, set the errno from the stat call. 756 */ 757 if (ISSET(FTS_LOGICAL) || follow) { 758 if (stat(p->fts_accpath, sbp)) { 759 saved_errno = errno; 760 if (!lstat(p->fts_accpath, sbp)) { 761 errno = 0; 762 return (FTS_SLNONE); 763 } 764 p->fts_errno = saved_errno; 765 goto err; 766 } 767 } else if (lstat(p->fts_accpath, sbp)) { 768 p->fts_errno = errno; 769 err: memset(sbp, 0, sizeof(struct stat)); 770 return (FTS_NS); 771 } 772 773 if (S_ISDIR(sbp->st_mode)) { 774 /* 775 * Set the device/inode. Used to find cycles and check for 776 * crossing mount points. Also remember the link count, used 777 * in fts_build to limit the number of stat calls. It is 778 * understood that these fields are only referenced if fts_info 779 * is set to FTS_D. 780 */ 781 dev = p->fts_dev = sbp->st_dev; 782 ino = p->fts_ino = sbp->st_ino; 783 p->fts_nlink = sbp->st_nlink; 784 785 if (ISDOT(p->fts_name)) 786 return (FTS_DOT); 787 788 /* 789 * Cycle detection is done by brute force when the directory 790 * is first encountered. If the tree gets deep enough or the 791 * number of symbolic links to directories is high enough, 792 * something faster might be worthwhile. 793 */ 794 for (t = p->fts_parent; 795 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 796 if (ino == t->fts_ino && dev == t->fts_dev) { 797 p->fts_cycle = t; 798 return (FTS_DC); 799 } 800 return (FTS_D); 801 } 802 if (S_ISLNK(sbp->st_mode)) 803 return (FTS_SL); 804 if (S_ISREG(sbp->st_mode)) 805 return (FTS_F); 806 return (FTS_DEFAULT); 807 } 808 809 static FTSENT * 810 fts_sort(sp, head, nitems) 811 FTS *sp; 812 FTSENT *head; 813 register int nitems; 814 { 815 register FTSENT **ap, *p; 816 817 /* 818 * Construct an array of pointers to the structures and call qsort(3). 819 * Reassemble the array in the order returned by qsort. If unable to 820 * sort for memory reasons, return the directory entries in their 821 * current order. Allocate enough space for the current needs plus 822 * 40 so don't realloc one entry at a time. 823 */ 824 if (nitems > sp->fts_nitems) { 825 sp->fts_nitems = nitems + 40; 826 if ((sp->fts_array = realloc(sp->fts_array, 827 (size_t)(sp->fts_nitems * sizeof(FTSENT *)))) == NULL) { 828 sp->fts_nitems = 0; 829 return (head); 830 } 831 } 832 for (ap = sp->fts_array, p = head; p; p = p->fts_link) 833 *ap++ = p; 834 qsort((void *)sp->fts_array, nitems, sizeof(FTSENT *), sp->fts_compar); 835 for (head = *(ap = sp->fts_array); --nitems; ++ap) 836 ap[0]->fts_link = ap[1]; 837 ap[0]->fts_link = NULL; 838 return (head); 839 } 840 841 static FTSENT * 842 fts_alloc(sp, name, namelen) 843 FTS *sp; 844 char *name; 845 register int namelen; 846 { 847 register FTSENT *p; 848 size_t len; 849 850 /* 851 * The file name is a variable length array and no stat structure is 852 * necessary if the user has set the nostat bit. Allocate the FTSENT 853 * structure, the file name and the stat structure in one chunk, but 854 * be careful that the stat structure is reasonably aligned. Since the 855 * fts_name field is declared to be of size 1, the fts_name pointer is 856 * namelen + 2 before the first possible address of the stat structure. 857 */ 858 len = sizeof(FTSENT) + namelen; 859 if (!ISSET(FTS_NOSTAT)) 860 len += sizeof(struct stat) + ALIGNBYTES; 861 if ((p = malloc(len)) == NULL) 862 return (NULL); 863 864 /* Copy the name plus the trailing NULL. */ 865 memmove(p->fts_name, name, namelen + 1); 866 867 if (!ISSET(FTS_NOSTAT)) 868 p->fts_statp = (struct stat *)ALIGN(p->fts_name + namelen + 2); 869 p->fts_namelen = namelen; 870 p->fts_path = sp->fts_path; 871 p->fts_errno = 0; 872 p->fts_flags = 0; 873 p->fts_instr = FTS_NOINSTR; 874 p->fts_number = 0; 875 p->fts_pointer = NULL; 876 return (p); 877 } 878 879 static void 880 fts_lfree(head) 881 register FTSENT *head; 882 { 883 register FTSENT *p; 884 885 /* Free a linked list of structures. */ 886 while (p = head) { 887 head = head->fts_link; 888 free(p); 889 } 890 } 891 892 /* 893 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 894 * Most systems will allow creation of paths much longer than MAXPATHLEN, even 895 * though the kernel won't resolve them. Add the size (not just what's needed) 896 * plus 256 bytes so don't realloc the path 2 bytes at a time. 897 */ 898 static int 899 fts_palloc(sp, more) 900 FTS *sp; 901 size_t more; 902 { 903 sp->fts_pathlen += more + 256; 904 sp->fts_path = realloc(sp->fts_path, (size_t)sp->fts_pathlen); 905 return (sp->fts_path == NULL); 906 } 907 908 /* 909 * When the path is realloc'd, have to fix all of the pointers in structures 910 * already returned. 911 */ 912 static void 913 fts_padjust(sp, addr) 914 FTS *sp; 915 void *addr; 916 { 917 FTSENT *p; 918 919 #define ADJUST(p) { \ 920 (p)->fts_accpath = \ 921 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \ 922 (p)->fts_path = addr; \ 923 } 924 /* Adjust the current set of children. */ 925 for (p = sp->fts_child; p; p = p->fts_link) 926 ADJUST(p); 927 928 /* Adjust the rest of the tree. */ 929 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 930 ADJUST(p); 931 p = p->fts_link ? p->fts_link : p->fts_parent; 932 } 933 } 934 935 static size_t 936 fts_maxarglen(argv) 937 char * const *argv; 938 { 939 size_t len, max; 940 941 for (max = 0; *argv; ++argv) 942 if ((len = strlen(*argv)) > max) 943 max = len; 944 return (max); 945 } 946