rm/rm.c

   1 /*-
   2  * Copyright (c) 1990, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifndef lint
  35 static const char copyright[] =
  36 "@(#) Copyright (c) 1990, 1993, 1994\n\
  37         The Regents of the University of California.  All rights reserved.\n";
  38 #endif /* not lint */
  39
  40 #ifndef lint
  41 #if 0
  42 static char sccsid[] = "@(#)rm.c        8.5 (Berkeley) 4/18/94";
  43 #else
  44 static const char rcsid[] =
  45   "$FreeBSD: src/bin/rm/rm.c,v 1.33 2001/06/13 15:01:25 ru Exp $";
  46 #endif
  47 #endif /* not lint */
  48
  49 #include <sys/stat.h>
  50 #include <sys/param.h>
  51 #include <sys/mount.h>
  52
  53 #include <err.h>
  54 #include <errno.h>
  55 #include <fcntl.h>
  56 #include <fts.h>
  57 #include <stdio.h>
  58 #include <stdlib.h>
  59 #include <string.h>
  60 #include <sysexits.h>
  61 #include <unistd.h>
  62
  63 #ifdef __APPLE__
  64 #include "get_compat.h"
  65 #else
  66 #define COMPAT_MODE(func, mode) 1
  67 #endif
  68
  69 int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
  70 uid_t uid;
  71
  72 int     check __P((char *, char *, struct stat *));
  73 int checkdir __P((char *));
  74 int             yes_or_no __P((void));
  75 void    checkdot __P((char **));
  76 void    rm_file __P((char **));
  77 void    rm_overwrite __P((char *, struct stat *));
  78 void    rm_tree __P((char **));
  79 void    usage __P((void));
  80
  81 /*
  82  * rm --
  83  *      This rm is different from historic rm's, but is expected to match
  84  *      POSIX 1003.2 behavior.  The most visible difference is that -f
  85  *      has two specific effects now, ignore non-existent files and force
  86  *      file removal.
  87  */
  88 int
  89 main(argc, argv)
  90         int argc;
  91         char *argv[];
  92 {
  93         int ch, rflag;
  94         char *p;
  95
  96         /*
  97          * Test for the special case where the utility is called as
  98          * "unlink", for which the functionality provided is greatly
  99          * simplified.
 100          */
 101         if ((p = rindex(argv[0], '/')) == NULL)
 102                 p = argv[0];
 103         else
 104                 ++p;
 105         if (strcmp(p, "unlink") == 0) {
 106                 if (argc == 2) {
 107                         rm_file(&argv[1]);
 108                         exit(eval);
 109                 } else
 110                         usage();
 111         }
 112
 113         Pflag = rflag = 0;
 114         while ((ch = getopt(argc, argv, "dfiPRrvW")) != -1)
 115                 switch(ch) {
 116                 case 'd':
 117                         dflag = 1;
 118                         break;
 119                 case 'f':
 120                         fflag = 1;
 121                         iflag = 0;
 122                         break;
 123                 case 'i':
 124                         fflag = 0;
 125                         iflag = 1;
 126                         break;
 127                 case 'P':
 128                         Pflag = 1;
 129                         break;
 130                 case 'R':
 131                 case 'r':                       /* Compatibility. */
 132                         rflag = 1;
 133                         break;
 134                 case 'v':
 135                         vflag = 1;
 136                         break;
 137                 case 'W':
 138                         Wflag = 1;
 139                         break;
 140                 default:
 141                         usage();
 142                 }
 143         argc -= optind;
 144         argv += optind;
 145
 146         if (argc < 1) {
 147                 if (fflag)
 148                         return 0;
 149                 usage();
 150         }
 151
 152         checkdot(argv);
 153         uid = geteuid();
 154
 155         if (*argv) {
 156                 stdin_ok = isatty(STDIN_FILENO);
 157
 158                 if (rflag)
 159                         rm_tree(argv);
 160                 else
 161                         rm_file(argv);
 162         }
 163
 164         exit (eval);
 165 }
 166
 167 void
 168 rm_tree(argv)
 169         char **argv;
 170 {
 171         FTS *fts;
 172         FTSENT *p;
 173         int needstat;
 174         int flags;
 175         int rval;
 176         int wantConformance = COMPAT_MODE("bin/rm", "unix2003");
 177         /*
 178          * Remove a file hierarchy.  If forcing removal (-f), or interactive
 179          * (-i) or can't ask anyway (stdin_ok), don't stat the file.
 180          */
 181         needstat = !uid || (!fflag && !iflag && stdin_ok);
 182
 183         /*
 184          * If the -i option is specified, the user can skip on the pre-order
 185          * visit.  The fts_number field flags skipped directories.
 186          */
 187 #define SKIPPED 1
 188
 189         flags = FTS_PHYSICAL;
 190         if (!needstat)
 191                 flags |= FTS_NOSTAT;
 192         if (Wflag)
 193                 flags |= FTS_WHITEOUT;
 194         if (!(fts = fts_open(argv, flags, NULL))) {
 195                 if (fflag && errno == ENOENT)
 196                         return;
 197                 err(1, NULL);
 198         }
 199         while ((p = fts_read(fts)) != NULL) {
 200                 switch (p->fts_info) {
 201                 case FTS_DNR:
 202                         if (!fflag || p->fts_errno != ENOENT) {
 203                                 warnx("%s: %s",
 204                                     p->fts_path, strerror(p->fts_errno));
 205                                 eval = 1;
 206                         }
 207                         continue;
 208                 case FTS_ERR:
 209                         errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
 210                 case FTS_NS:
 211                         /*
 212                          * FTS_NS: assume that if can't stat the file, it
 213                          * can't be unlinked.
 214                          */
 215                         if (!needstat)
 216                                 break;
 217                         if (!fflag || p->fts_errno != ENOENT) {
 218                                 warnx("%s: %s",
 219                                     p->fts_path, strerror(p->fts_errno));
 220                                 eval = 1;
 221                         }
 222                         continue;
 223                 case FTS_D:
 224                         /* Pre-order: give user chance to skip. */
 225                         /* In conformance mode the user is prompted to skip processing the contents.
 226                          * Then the option to delete the dir is presented post-order */
 227                         if (!fflag &&
 228                                         ( (wantConformance && !checkdir(p->fts_path)) ||
 229                                           (!wantConformance && !check(p->fts_path, p->fts_accpath, p->fts_statp))
 230                                         )
 231                            ){
 232                                 (void)fts_set(fts, p, FTS_SKIP);
 233                                 p->fts_number = SKIPPED;
 234                         }
 235                         else if (!uid &&
 236                                  (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 237                                  !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 238                                  chflags(p->fts_accpath,
 239                                          p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
 240                                 goto err;
 241                         continue;
 242                 case FTS_DP:
 243                         /* Post-order: see if user skipped. */
 244                         if(p->fts_number == SKIPPED)/*in legacy mode, the user was prompted pre-order */
 245                                 continue;
 246                         else if(wantConformance)
 247                         {
 248                                 /* delete directory if force is on, or if user answers Y to prompt */
 249                                 if(fflag || check(p->fts_path, p->fts_accpath, p->fts_statp))
 250                                         break;
 251                                 else
 252                                         continue;
 253                         }
 254                         break;
 255                 default:
 256                         if (!fflag &&
 257                             !check(p->fts_path, p->fts_accpath, p->fts_statp))
 258                                 continue;
 259                 }
 260
 261                 rval = 0;
 262                 if (!uid &&
 263                     (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 264                     !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
 265                         rval = chflags(p->fts_accpath,
 266                                        p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
 267                 if (rval == 0) {
 268                         /*
 269                          * If we can't read or search the directory, may still be
 270                          * able to remove it.  Don't print out the un{read,search}able
 271                          * message unless the remove fails.
 272                          */
 273                         switch (p->fts_info) {
 274                         case FTS_DP:
 275                         case FTS_DNR:
 276                                 rval = rmdir(p->fts_accpath);
 277                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 278                                         if (rval == 0 && vflag)
 279                                                 (void)printf("%s\n",
 280                                                     p->fts_path);
 281                                         continue;
 282                                 }
 283                                 break;
 284
 285                         case FTS_W:
 286                                 rval = undelete(p->fts_accpath);
 287                                 if (rval == 0 && (fflag && errno == ENOENT)) {
 288                                         if (vflag)
 289                                                 (void)printf("%s\n",
 290                                                     p->fts_path);
 291                                         continue;
 292                                 }
 293                                 break;
 294
 295                         default:
 296                                 if (Pflag)
 297                                         rm_overwrite(p->fts_accpath, NULL);
 298                                 rval = unlink(p->fts_accpath);
 299                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 300                                         if (rval == 0 && vflag)
 301                                                 (void)printf("%s\n",
 302                                                     p->fts_path);
 303                                         continue;
 304                                 }
 305                         }
 306                 }
 307 err:
 308                 warn("%s", p->fts_path);
 309                 eval = 1;
 310         }
 311         if (errno)
 312                 err(1, "fts_read");
 313 }
 314
 315 void
 316 rm_file(argv)
 317         char **argv;
 318 {
 319         struct stat sb;
 320         int rval;
 321         char *f;
 322
 323         /*
 324          * Remove a file.  POSIX 1003.2 states that, by default, attempting
 325          * to remove a directory is an error, so must always stat the file.
 326          */
 327         while ((f = *argv++) != NULL) {
 328                 /* Assume if can't stat the file, can't unlink it. */
 329                 if (lstat(f, &sb)) {
 330                         if (Wflag) {
 331                                 sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
 332                         } else {
 333                                 if (!fflag || errno != ENOENT) {
 334                                         warn("%s", f);
 335                                         eval = 1;
 336                                 }
 337                                 continue;
 338                         }
 339                 } else if (Wflag) {
 340                         warnx("%s: %s", f, strerror(EEXIST));
 341                         eval = 1;
 342                         continue;
 343                 }
 344
 345                 if (S_ISDIR(sb.st_mode) && !dflag) {
 346                         warnx("%s: is a directory", f);
 347                         eval = 1;
 348                         continue;
 349                 }
 350                 if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
 351                         continue;
 352                 rval = 0;
 353                 if (!uid &&
 354                     (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 355                     !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
 356                         rval = chflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
 357                 if (rval == 0) {
 358                         if (S_ISWHT(sb.st_mode))
 359                                 rval = undelete(f);
 360                         else if (S_ISDIR(sb.st_mode))
 361                                 rval = rmdir(f);
 362                         else {
 363                                 if (Pflag)
 364                                         rm_overwrite(f, &sb);
 365                                 rval = unlink(f);
 366                         }
 367                 }
 368                 if (rval && (!fflag || errno != ENOENT)) {
 369                         warn("%s", f);
 370                         eval = 1;
 371                 }
 372                 if (vflag && rval == 0)
 373                         (void)printf("%s\n", f);
 374         }
 375 }
 376
 377 /*
 378  * rm_overwrite --
 379  *      Overwrite the file 3 times with varying bit patterns.
 380  *
 381  * XXX
 382  * This is a cheap way to *really* delete files.  Note that only regular
 383  * files are deleted, directories (and therefore names) will remain.
 384  * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
 385  * System V file system).  In a logging file system, you'll have to have
 386  * kernel support.
 387  */
 388 void
 389 rm_overwrite(file, sbp)
 390         char *file;
 391         struct stat *sbp;
 392 {
 393         struct stat sb;
 394         struct statfs fsb;
 395         off_t len;
 396         int bsize, fd, wlen;
 397         char *buf = NULL;
 398
 399         fd = -1;
 400         if (sbp == NULL) {
 401                 if (lstat(file, &sb))
 402                         goto err;
 403                 sbp = &sb;
 404         }
 405         if (!S_ISREG(sbp->st_mode))
 406                 return;
 407         if ((fd = open(file, O_WRONLY, 0)) == -1)
 408                 goto err;
 409         if (fstatfs(fd, &fsb) == -1)
 410                 goto err;
 411         bsize = MAX(fsb.f_iosize, 1024);
 412         if ((buf = malloc(bsize)) == NULL)
 413                 err(1, "malloc");
 414
 415 #define PASS(byte) {                                                    \
 416         memset(buf, byte, bsize);                                       \
 417         for (len = sbp->st_size; len > 0; len -= wlen) {                \
 418                 wlen = len < bsize ? len : bsize;                       \
 419                 if (write(fd, buf, wlen) != wlen)                       \
 420                         goto err;                                       \
 421         }                                                               \
 422 }
 423         PASS(0xff);
 424         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 425                 goto err;
 426         PASS(0x00);
 427         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 428                 goto err;
 429         PASS(0xff);
 430         if (!fsync(fd) && !close(fd)) {
 431                 free(buf);
 432                 return;
 433         }
 434
 435 err:    eval = 1;
 436         if (buf)
 437                 free(buf);
 438         warn("%s", file);
 439 }
 440
 441 int
 442 yes_or_no()
 443 {
 444         int ch, first;
 445         (void)fflush(stderr);
 446
 447         first = ch = getchar();
 448         while (ch != '\n' && ch != EOF)
 449                 ch = getchar();
 450         return (first == 'y' || first == 'Y');
 451 }
 452
 453 int
 454 checkdir(path)
 455         char *path;
 456 {
 457         if(!iflag)
 458                 return 1;       //if not interactive, process directory's contents
 459         (void)fprintf(stderr, "examine files in directory %s? ", path);
 460         return yes_or_no();
 461 }
 462
 463 int
 464 check(path, name, sp)
 465         char *path, *name;
 466         struct stat *sp;
 467 {
 468         char modep[15], *flagsp;
 469
 470         /* Check -i first. */
 471         if (iflag)
 472                 (void)fprintf(stderr, "remove %s? ", path);
 473         else {
 474                 /*
 475                  * If it's not a symbolic link and it's unwritable and we're
 476                  * talking to a terminal, ask.  Symbolic links are excluded
 477                  * because their permissions are meaningless.  Check stdin_ok
 478                  * first because we may not have stat'ed the file.
 479                  */
 480                 if (!stdin_ok || S_ISLNK(sp->st_mode) ||
 481                     (!access(name, W_OK) &&
 482                     !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 483                     (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
 484                         return (1);
 485                 strmode(sp->st_mode, modep);
 486                 if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
 487                         err(1, NULL);
 488                 (void)fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
 489                     modep + 1, modep[9] == ' ' ? "" : " ",
 490                     user_from_uid(sp->st_uid, 0),
 491                     group_from_gid(sp->st_gid, 0),
 492                     *flagsp ? flagsp : "", *flagsp ? " " : "",
 493                     path);
 494                 free(flagsp);
 495         }
 496         return yes_or_no();
 497 }
 498
 499
 500 #define ISDOT(a)        ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
 501 void
 502 checkdot(argv)
 503         char **argv;
 504 {
 505         char *p, **save, **t;
 506         int complained;
 507
 508         complained = 0;
 509         for (t = argv; *t;) {
 510                 if ((p = strrchr(*t, '/')) != NULL)
 511                         ++p;
 512                 else
 513                         p = *t;
 514                 if (ISDOT(p)) {
 515                         if (!complained++)
 516                                 warnx("\".\" and \"..\" may not be removed");
 517                         eval = 1;
 518                         for (save = t; (t[0] = t[1]) != NULL; ++t)
 519                                 continue;
 520                         t = save;
 521                 } else
 522                         ++t;
 523         }
 524 }
 525
 526 void
 527 usage()
 528 {
 529
 530         (void)fprintf(stderr, "%s\n%s\n",
 531             "usage: rm [-f | -i] [-dPRrvW] file ...",
 532             "       unlink file");
 533         exit(EX_USAGE);
 534 }