find/ftsfind.c

   1 /* find -- search for files in a directory hierarchy (fts version)
   2    Copyright (C) 1990, 91, 92, 93, 94, 2000,
   3                  2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation, either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17 */
  18
  19 /* This file was written by James Youngman, based on find.c.
  20
  21    GNU find was written by Eric Decker <cire@cisco.com>,
  22    with enhancements by David MacKenzie <djm@gnu.org>,
  23    Jay Plett <jay@silence.princeton.nj.us>,
  24    and Tim Wood <axolotl!tim@toad.com>.
  25    The idea for -print0 and xargs -0 came from
  26    Dan Bernstein <brnstnd@kramden.acf.nyu.edu>.
  27 */
  28
  29
  30 #include <config.h>
  31 #include "defs.h"
  32
  33
  34 #define USE_SAFE_CHDIR 1
  35 #undef  STAT_MOUNTPOINTS
  36
  37
  38 #include <errno.h>
  39 #include <assert.h>
  40
  41 #ifdef HAVE_FCNTL_H
  42 #include <fcntl.h>
  43 #else
  44 #include <sys/file.h>
  45 #endif
  46 #include <sys/stat.h>
  47
  48 #include <unistd.h>
  49
  50 #include "xalloc.h"
  51 #include "closeout.h"
  52 #include <modetype.h>
  53 #include "quotearg.h"
  54 #include "quote.h"
  55 #include "fts_.h"
  56 #include "openat.h"
  57 #include "save-cwd.h"
  58 #include "xgetcwd.h"
  59 #include "error.h"
  60 #include "dircallback.h"
  61
  62 #ifdef HAVE_LOCALE_H
  63 #include <locale.h>
  64 #endif
  65
  66 #if ENABLE_NLS
  67 # include <libintl.h>
  68 # define _(Text) gettext (Text)
  69 #else
  70 # define _(Text) Text
  71 #define textdomain(Domain)
  72 #define bindtextdomain(Package, Directory)
  73 #endif
  74 #ifdef gettext_noop
  75 # define N_(String) gettext_noop (String)
  76 #else
  77 /* See locate.c for explanation as to why not use (String) */
  78 # define N_(String) String
  79 #endif
  80
  81
  82 static void set_close_on_exec(int fd)
  83 {
  84 #if defined F_GETFD && defined FD_CLOEXEC
  85   int flags;
  86   flags = fcntl(fd, F_GETFD);
  87   if (flags >= 0)
  88     {
  89       flags |= FD_CLOEXEC;
  90       fcntl(fd, F_SETFD, flags);
  91     }
  92 #endif
  93 }
  94
  95
  96
  97 /* FTS_TIGHT_CYCLE_CHECK tries to work around Savannah bug #17877
  98  * (but actually using it doesn't fix the bug).
  99  */
 100 static int ftsoptions = FTS_NOSTAT|FTS_TIGHT_CYCLE_CHECK;
 101
 102 static int prev_depth = INT_MIN; /* fts_level can be < 0 */
 103 static int curr_fd = -1;
 104
 105 int get_current_dirfd(void)
 106 {
 107   if (ftsoptions & FTS_CWDFD)
 108     {
 109       assert (curr_fd != -1);
 110       assert ( (AT_FDCWD == curr_fd) || (curr_fd >= 0) );
 111
 112       if (AT_FDCWD == curr_fd)
 113         return starting_desc;
 114       else
 115         return curr_fd;
 116     }
 117   else
 118     {
 119       return AT_FDCWD;
 120     }
 121 }
 122
 123 static void left_dir(void)
 124 {
 125   if (ftsoptions & FTS_CWDFD)
 126     {
 127       if (curr_fd >= 0)
 128         {
 129           close(curr_fd);
 130           curr_fd = -1;
 131         }
 132     }
 133   else
 134     {
 135       /* do nothing. */
 136     }
 137 }
 138
 139 /*
 140  * Signal that we are now inside a directory pointed to by dirfd.
 141  * The caller can't tell if this is the first time this happens, so
 142  * we have to be careful not to call dup() more than once
 143  */
 144 static void inside_dir(int dirfd)
 145 {
 146   if (ftsoptions & FTS_CWDFD)
 147     {
 148       assert (dirfd == AT_FDCWD || dirfd >= 0);
 149
 150       state.cwd_dir_fd = dirfd;
 151       if (curr_fd < 0)
 152         {
 153           if (AT_FDCWD == dirfd)
 154             {
 155               curr_fd = AT_FDCWD;
 156             }
 157           else if (dirfd >= 0)
 158             {
 159               curr_fd = dup(dirfd);
 160               set_close_on_exec(curr_fd);
 161             }
 162           else
 163             {
 164               /* curr_fd is invalid, but dirfd is also invalid.
 165                * This should not have happened.
 166                */
 167               assert (curr_fd >= 0 || dirfd >= 0);
 168             }
 169         }
 170     }
 171   else
 172     {
 173       /* FTS_CWDFD is not in use.  We can always assume that
 174        * AT_FDCWD refers to the directory we are currentl searching.
 175        *
 176        * Therefore there is nothing to do.
 177        */
 178     }
 179 }
 180
 181
 182
 183 #ifdef STAT_MOUNTPOINTS
 184 static void init_mounted_dev_list(void);
 185 #endif
 186 \f
 187 /* We have encountered an error which should affect the exit status.
 188  * This is normally used to change the exit status from 0 to 1.
 189  * However, if the exit status is already 2 for example, we don't want to
 190  * reduce it to 1.
 191  */
 192 static void
 193 error_severity(int level)
 194 {
 195   if (state.exit_status < level)
 196     state.exit_status = level;
 197 }
 198 \f
 199
 200 #define STRINGIFY(X) #X
 201 #define HANDLECASE(N) case N: return #N;
 202
 203 static char *
 204 get_fts_info_name(int info)
 205 {
 206   static char buf[10];
 207   switch (info)
 208     {
 209       HANDLECASE(FTS_D);
 210       HANDLECASE(FTS_DC);
 211       HANDLECASE(FTS_DEFAULT);
 212       HANDLECASE(FTS_DNR);
 213       HANDLECASE(FTS_DOT);
 214       HANDLECASE(FTS_DP);
 215       HANDLECASE(FTS_ERR);
 216       HANDLECASE(FTS_F);
 217       HANDLECASE(FTS_INIT);
 218       HANDLECASE(FTS_NS);
 219       HANDLECASE(FTS_NSOK);
 220       HANDLECASE(FTS_SL);
 221       HANDLECASE(FTS_SLNONE);
 222       HANDLECASE(FTS_W);
 223     default:
 224       sprintf(buf, "[%d]", info);
 225       return buf;
 226     }
 227 }
 228 \f
 229 static void
 230 visit(FTS *p, FTSENT *ent, struct stat *pstat)
 231 {
 232   struct predicate *eval_tree;
 233
 234   state.curdepth = ent->fts_level;
 235   state.have_stat = (ent->fts_info != FTS_NS) && (ent->fts_info != FTS_NSOK);
 236   state.rel_pathname = ent->fts_accpath;
 237   state.cwd_dir_fd   = p->fts_cwd_fd;
 238
 239   /* Apply the predicates to this path. */
 240   eval_tree = get_eval_tree();
 241   apply_predicate(ent->fts_path, pstat, eval_tree);
 242
 243   /* Deal with any side effects of applying the predicates. */
 244   if (state.stop_at_current_level)
 245     {
 246       fts_set(p, ent, FTS_SKIP);
 247     }
 248 }
 249 \f
 250 static const char*
 251 partial_quotearg_n(int n, char *s, size_t len, enum quoting_style style)
 252 {
 253   if (0 == len)
 254     {
 255       return quotearg_n_style(n, style, "");
 256     }
 257   else
 258     {
 259       char saved;
 260       const char *result;
 261
 262       saved = s[len];
 263       s[len] = 0;
 264       result = quotearg_n_style(n, style, s);
 265       s[len] = saved;
 266       return result;
 267     }
 268 }
 269
 270 \f
 271 /* We've detected a file system loop.   This is caused by one of
 272  * two things:
 273  *
 274  * 1. Option -L is in effect and we've hit a symbolic link that
 275  *    points to an ancestor.  This is harmless.  We won't traverse the
 276  *    symbolic link.
 277  *
 278  * 2. We have hit a real cycle in the directory hierarchy.  In this
 279  *    case, we issue a diagnostic message (POSIX requires this) and we
 280  *    skip that directory entry.
 281  */
 282 static void
 283 issue_loop_warning(FTSENT * ent)
 284 {
 285   if (S_ISLNK(ent->fts_statp->st_mode))
 286     {
 287       error(0, 0,
 288             _("Symbolic link %s is part of a loop in the directory hierarchy; we have already visited the directory to which it points."),
 289             safely_quote_err_filename(0, ent->fts_path));
 290     }
 291   else
 292     {
 293       /* We have found an infinite loop.  POSIX requires us to
 294        * issue a diagnostic.  Usually we won't get to here
 295        * because when the leaf optimisation is on, it will cause
 296        * the subdirectory to be skipped.  If /a/b/c/d is a hard
 297        * link to /a/b, then the link count of /a/b/c is 2,
 298        * because the ".." entry of /a/b/c/d points to /a, not
 299        * to /a/b/c.
 300        */
 301       error(0, 0,
 302             _("File system loop detected; "
 303               "%s is part of the same file system loop as %s."),
 304             safely_quote_err_filename(0, ent->fts_path),
 305             partial_quotearg_n(1,
 306                                ent->fts_cycle->fts_path,
 307                                ent->fts_cycle->fts_pathlen,
 308                                options.err_quoting_style));
 309     }
 310 }
 311 \f
 312 /*
 313  * Return true if NAME corresponds to a file which forms part of a
 314  * symbolic link loop.  The command
 315  *      rm -f a b; ln -s a b; ln -s b a
 316  * produces such a loop.
 317  */
 318 static boolean
 319 symlink_loop(const char *name)
 320 {
 321   struct stat stbuf;
 322   int rv;
 323   if (following_links())
 324     rv = stat(name, &stbuf);
 325   else
 326     rv = lstat(name, &stbuf);
 327   return (0 != rv) && (ELOOP == errno);
 328 }
 329 \f
 330
 331 static int
 332 complete_execdirs_cb(void *context)
 333 {
 334   (void) context;
 335   /* By the tme this callback is called, the current directory is correct. */
 336   complete_pending_execdirs(AT_FDCWD);
 337   return 0;
 338 }
 339
 340 static void
 341 show_outstanding_execdirs(FILE *fp)
 342 {
 343   if (options.debug_options & DebugExec)
 344     {
 345       int seen=0;
 346       struct predicate *p;
 347       p = get_eval_tree();
 348       fprintf(fp, "Outstanding execdirs:");
 349
 350       while (p)
 351         {
 352           const char *pfx;
 353
 354           if (pred_is(p, pred_execdir))
 355             pfx = "-execdir";
 356           else if (pred_is(p, pred_okdir))
 357             pfx = "-okdir";
 358           else
 359             pfx = NULL;
 360           if (pfx)
 361             {
 362               int i;
 363               const struct exec_val *execp = &p->args.exec_vec;
 364               ++seen;
 365
 366               fprintf(fp, "%s ", pfx);
 367               if (execp->multiple)
 368                 fprintf(fp, "multiple ");
 369               fprintf(fp, "%d args: ", execp->state.cmd_argc);
 370               for (i=0; i<execp->state.cmd_argc; ++i)
 371                 {
 372                   fprintf(fp, "%s ", execp->state.cmd_argv[i]);
 373                 }
 374               fprintf(fp, "\n");
 375             }
 376           p = p->pred_next;
 377         }
 378       if (!seen)
 379         fprintf(fp, " none\n");
 380     }
 381   else
 382     {
 383       /* No debug output is wanted. */
 384     }
 385 }
 386
 387
 388
 389 \f
 390 static void
 391 consider_visiting(FTS *p, FTSENT *ent)
 392 {
 393   struct stat statbuf;
 394   mode_t mode;
 395   int ignore, isdir;
 396
 397   if (options.debug_options & DebugSearch)
 398     fprintf(stderr,
 399             "consider_visiting: fts_info=%-6s, fts_level=%2d, prev_depth=%d "
 400             "fts_path=%s, fts_accpath=%s\n",
 401             get_fts_info_name(ent->fts_info),
 402             (int)ent->fts_level, prev_depth,
 403             quotearg_n_style(0, options.err_quoting_style, ent->fts_path),
 404             quotearg_n_style(1, options.err_quoting_style, ent->fts_accpath));
 405
 406   if (ent->fts_info == FTS_DP)
 407     {
 408       left_dir();
 409     }
 410   else if (ent->fts_level > prev_depth || ent->fts_level==0)
 411     {
 412       left_dir();
 413     }
 414   inside_dir(p->fts_cwd_fd);
 415   prev_depth = ent->fts_level;
 416
 417
 418   /* Cope with various error conditions. */
 419   if (ent->fts_info == FTS_ERR
 420       || ent->fts_info == FTS_DNR)
 421     {
 422       error(0, ent->fts_errno, "%s",
 423             safely_quote_err_filename(0, ent->fts_path));
 424       error_severity(1);
 425       return;
 426     }
 427   else if (ent->fts_info == FTS_DC)
 428     {
 429       issue_loop_warning(ent);
 430       error_severity(1);
 431       return;
 432     }
 433   else if (ent->fts_info == FTS_SLNONE)
 434     {
 435       /* fts_read() claims that ent->fts_accpath is a broken symbolic
 436        * link.  That would be fine, but if this is part of a symbolic
 437        * link loop, we diagnose the problem and also ensure that the
 438        * eventual return value is nonzero.   Note that while the path
 439        * we stat is local (fts_accpath), we print the fill path name
 440        * of the file (fts_path) in the error message.
 441        */
 442       if (symlink_loop(ent->fts_accpath))
 443         {
 444           error(0, ELOOP, "%s", safely_quote_err_filename(0, ent->fts_path));
 445           error_severity(1);
 446           return;
 447         }
 448     }
 449   else if (ent->fts_info == FTS_NS)
 450     {
 451       if (ent->fts_level == 0)
 452         {
 453           /* e.g., nonexistent starting point */
 454           error(0, ent->fts_errno, "%s",
 455                 safely_quote_err_filename(0, ent->fts_path));
 456           error_severity(1);    /* remember problem */
 457           return;
 458         }
 459       else
 460         {
 461           /* The following if statement fixes Savannah bug #19605
 462            * (failure to diagnose a symbolic link loop)
 463            */
 464           if (symlink_loop(ent->fts_accpath))
 465             {
 466               error(0, ELOOP, "%s",
 467                     safely_quote_err_filename(0, ent->fts_path));
 468               error_severity(1);
 469               return;
 470             }
 471         }
 472     }
 473
 474   /* Cope with the usual cases. */
 475   if (ent->fts_info == FTS_NSOK
 476       || ent->fts_info == FTS_NS /* e.g. symlink loop */)
 477     {
 478       assert (!state.have_stat);
 479       assert (!state.have_type);
 480       state.type = mode = 0;
 481     }
 482   else
 483     {
 484       state.have_stat = true;
 485       state.have_type = true;
 486       statbuf = *(ent->fts_statp);
 487       state.type = mode = statbuf.st_mode;
 488
 489       if (00000 == mode)
 490         {
 491           /* Savannah bug #16378. */
 492           error(0, 0, _("Warning: file %s appears to have mode 0000"),
 493                 quotearg_n_style(0, options.err_quoting_style, ent->fts_path));
 494         }
 495     }
 496
 497   if (mode)
 498     {
 499       if (!digest_mode(mode, ent->fts_path, ent->fts_name, &statbuf, 0))
 500         return;
 501     }
 502
 503   /* examine this item. */
 504   ignore = 0;
 505   isdir = S_ISDIR(statbuf.st_mode)
 506     || (FTS_D  == ent->fts_info)
 507     || (FTS_DP == ent->fts_info)
 508     || (FTS_DC == ent->fts_info);
 509
 510   if (isdir && (ent->fts_info == FTS_NSOK))
 511     {
 512       /* This is a directory, but fts did not stat it, so
 513        * presumably would not be planning to search its
 514        * children.  Force a stat of the file so that the
 515        * children can be checked.
 516        */
 517       fts_set(p, ent, FTS_AGAIN);
 518       return;
 519     }
 520
 521   if (options.maxdepth >= 0)
 522     {
 523       if (ent->fts_level >= options.maxdepth)
 524         {
 525           fts_set(p, ent, FTS_SKIP); /* descend no further */
 526
 527           if (ent->fts_level > options.maxdepth)
 528             ignore = 1;         /* don't even look at this one */
 529         }
 530     }
 531
 532   if ( (ent->fts_info == FTS_D) && !options.do_dir_first )
 533     {
 534       /* this is the preorder visit, but user said -depth */
 535       ignore = 1;
 536     }
 537   else if ( (ent->fts_info == FTS_DP) && options.do_dir_first )
 538     {
 539       /* this is the postorder visit, but user didn't say -depth */
 540       ignore = 1;
 541     }
 542   else if (ent->fts_level < options.mindepth)
 543     {
 544       ignore = 1;
 545     }
 546
 547   if (!ignore)
 548     {
 549       visit(p, ent, &statbuf);
 550     }
 551
 552   /* XXX: if we allow a build-up of pending arguments for "-execdir foo {} +"
 553    * we need to execute them in the same directory as we found the item.
 554    * If we are trying to do "find a -execdir echo {} +", we will need to
 555    * echo
 556    *      a while in the original working directory
 557    *      b while in a
 558    *      c while in b (just before leaving b)
 559    *
 560    * These restrictions are hard to satisfy while using fts().   The reason is
 561    * that it doesn't tell us just before we leave a directory.  For the moment,
 562    * we punt and don't allow the arguments to build up.
 563    */
 564   if (state.execdirs_outstanding)
 565     {
 566       show_outstanding_execdirs(stderr);
 567       run_in_dir(p->fts_cwd_fd, complete_execdirs_cb, NULL);
 568     }
 569
 570   if (ent->fts_info == FTS_DP)
 571     {
 572       /* we're leaving a directory. */
 573       state.stop_at_current_level = false;
 574     }
 575 }
 576
 577
 578 \f
 579 static void
 580 find(char *arg)
 581 {
 582   char * arglist[2];
 583   FTS *p;
 584   FTSENT *ent;
 585
 586
 587   state.starting_path_length = strlen(arg);
 588   inside_dir(AT_FDCWD);
 589
 590   arglist[0] = arg;
 591   arglist[1] = NULL;
 592
 593   switch (options.symlink_handling)
 594     {
 595     case SYMLINK_ALWAYS_DEREF:
 596       ftsoptions |= FTS_COMFOLLOW|FTS_LOGICAL;
 597       break;
 598
 599     case SYMLINK_DEREF_ARGSONLY:
 600       ftsoptions |= FTS_COMFOLLOW|FTS_PHYSICAL;
 601       break;
 602
 603     case SYMLINK_NEVER_DEREF:
 604       ftsoptions |= FTS_PHYSICAL;
 605       break;
 606     }
 607
 608   if (options.stay_on_filesystem)
 609     ftsoptions |= FTS_XDEV;
 610
 611   p = fts_open(arglist, ftsoptions, NULL);
 612   if (NULL == p)
 613     {
 614       error (0, errno, _("cannot search %s"),
 615              safely_quote_err_filename(0, arg));
 616     }
 617   else
 618     {
 619       while ( (ent=fts_read(p)) != NULL )
 620         {
 621           state.have_stat = false;
 622           state.have_type = false;
 623           state.type = 0;
 624           consider_visiting(p, ent);
 625         }
 626       fts_close(p);
 627       p = NULL;
 628     }
 629 }
 630
 631
 632 static void
 633 process_all_startpoints(int argc, char *argv[])
 634 {
 635   int i;
 636
 637   /* figure out how many start points there are */
 638   for (i = 0; i < argc && !looks_like_expression(argv[i], true); i++)
 639     {
 640       state.starting_path_length = strlen(argv[i]); /* TODO: is this redundant? */
 641       find(argv[i]);
 642     }
 643
 644   if (i == 0)
 645     {
 646       /*
 647        * We use a temporary variable here because some actions modify
 648        * the path temporarily.  Hence if we use a string constant,
 649        * we get a coredump.  The best example of this is if we say
 650        * "find -printf %H" (note, not "find . -printf %H").
 651        */
 652       char defaultpath[2] = ".";
 653       find(defaultpath);
 654     }
 655 }
 656
 657
 658
 659 \f
 660 int
 661 main (int argc, char **argv)
 662 {
 663   int end_of_leading_options = 0; /* First arg after any -H/-L etc. */
 664   struct predicate *eval_tree;
 665
 666   program_name = argv[0];
 667   state.exit_status = 0;
 668   state.execdirs_outstanding = false;
 669   state.cwd_dir_fd = AT_FDCWD;
 670
 671   /* Set the option defaults before we do the locale initialisation as
 672    * check_nofollow() needs to be executed in the POSIX locale.
 673    */
 674   set_option_defaults(&options);
 675
 676 #ifdef HAVE_SETLOCALE
 677   setlocale (LC_ALL, "");
 678 #endif
 679
 680   bindtextdomain (PACKAGE, LOCALEDIR);
 681   textdomain (PACKAGE);
 682   atexit (close_stdout);
 683
 684   /* Check for -P, -H or -L options.  Also -D and -O, which are
 685    * both GNU extensions.
 686    */
 687   end_of_leading_options = process_leading_options(argc, argv);
 688
 689   if (options.debug_options & DebugStat)
 690     options.xstat = debug_stat;
 691
 692 #ifdef DEBUG
 693   fprintf (stderr, "cur_day_start = %s", ctime (&options.cur_day_start));
 694 #endif /* DEBUG */
 695
 696
 697   /* We are now processing the part of the "find" command line
 698    * after the -H/-L options (if any).
 699    */
 700   eval_tree = build_expression_tree(argc, argv, end_of_leading_options);
 701
 702   /* safely_chdir() needs to check that it has ended up in the right place.
 703    * To avoid bailing out when something gets automounted, it checks if
 704    * the target directory appears to have had a directory mounted on it as
 705    * we chdir()ed.  The problem with this is that in order to notice that
 706    * a file system was mounted, we would need to lstat() all the mount points.
 707    * That strategy loses if our machine is a client of a dead NFS server.
 708    *
 709    * Hence if safely_chdir() and wd_sanity_check() can manage without needing
 710    * to know the mounted device list, we do that.
 711    */
 712   if (!options.open_nofollow_available)
 713     {
 714 #ifdef STAT_MOUNTPOINTS
 715       init_mounted_dev_list();
 716 #endif
 717     }
 718
 719
 720   starting_desc = open (".", O_RDONLY
 721 #if defined O_LARGEFILE
 722                         |O_LARGEFILE
 723 #endif
 724                         );
 725   if (0 <= starting_desc && fchdir (starting_desc) != 0)
 726     {
 727       close (starting_desc);
 728       starting_desc = -1;
 729     }
 730   if (starting_desc < 0)
 731     {
 732       starting_dir = xgetcwd ();
 733       if (! starting_dir)
 734         error (1, errno, _("cannot get current directory"));
 735     }
 736
 737
 738   process_all_startpoints(argc-end_of_leading_options, argv+end_of_leading_options);
 739
 740   /* If "-exec ... {} +" has been used, there may be some
 741    * partially-full command lines which have been built,
 742    * but which are not yet complete.   Execute those now.
 743    */
 744   show_success_rates(eval_tree);
 745   cleanup();
 746   return state.exit_status;
 747 }
 748
 749 boolean
 750 is_fts_enabled(int *fts_options)
 751 {
 752   /* this version of find (i.e. this main()) uses fts. */
 753   *fts_options = ftsoptions;
 754   return true;
 755 }