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 int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
  64 uid_t uid;
  65
  66 int     check __P((char *, char *, struct stat *));
  67 void    checkdot __P((char **));
  68 void    rm_file __P((char **));
  69 void    rm_overwrite __P((char *, struct stat *));
  70 void    rm_tree __P((char **));
  71 void    usage __P((void));
  72
  73 /*
  74  * rm --
  75  *      This rm is different from historic rm's, but is expected to match
  76  *      POSIX 1003.2 behavior.  The most visible difference is that -f
  77  *      has two specific effects now, ignore non-existent files and force
  78  *      file removal.
  79  */
  80 int
  81 main(argc, argv)
  82         int argc;
  83         char *argv[];
  84 {
  85         int ch, rflag;
  86         char *p;
  87
  88         /*
  89          * Test for the special case where the utility is called as
  90          * "unlink", for which the functionality provided is greatly
  91          * simplified.
  92          */
  93         if ((p = rindex(argv[0], '/')) == NULL)
  94                 p = argv[0];
  95         else
  96                 ++p;
  97         if (strcmp(p, "unlink") == 0) {
  98                 if (argc == 2) {
  99                         rm_file(&argv[1]);
 100                         exit(eval);
 101                 } else
 102                         usage();
 103         }
 104
 105         Pflag = rflag = 0;
 106         while ((ch = getopt(argc, argv, "dfiPRrvW")) != -1)
 107                 switch(ch) {
 108                 case 'd':
 109                         dflag = 1;
 110                         break;
 111                 case 'f':
 112                         fflag = 1;
 113                         iflag = 0;
 114                         break;
 115                 case 'i':
 116                         fflag = 0;
 117                         iflag = 1;
 118                         break;
 119                 case 'P':
 120                         Pflag = 1;
 121                         break;
 122                 case 'R':
 123                 case 'r':                       /* Compatibility. */
 124                         rflag = 1;
 125                         break;
 126                 case 'v':
 127                         vflag = 1;
 128                         break;
 129                 case 'W':
 130                         Wflag = 1;
 131                         break;
 132                 default:
 133                         usage();
 134                 }
 135         argc -= optind;
 136         argv += optind;
 137
 138         if (argc < 1) {
 139                 if (fflag)
 140                         return 0;
 141                 usage();
 142         }
 143
 144         checkdot(argv);
 145         uid = geteuid();
 146
 147         if (*argv) {
 148                 stdin_ok = isatty(STDIN_FILENO);
 149
 150                 if (rflag)
 151                         rm_tree(argv);
 152                 else
 153                         rm_file(argv);
 154         }
 155
 156         exit (eval);
 157 }
 158
 159 void
 160 rm_tree(argv)
 161         char **argv;
 162 {
 163         FTS *fts;
 164         FTSENT *p;
 165         int needstat;
 166         int flags;
 167         int rval;
 168
 169         /*
 170          * Remove a file hierarchy.  If forcing removal (-f), or interactive
 171          * (-i) or can't ask anyway (stdin_ok), don't stat the file.
 172          */
 173         needstat = !uid || (!fflag && !iflag && stdin_ok);
 174
 175         /*
 176          * If the -i option is specified, the user can skip on the pre-order
 177          * visit.  The fts_number field flags skipped directories.
 178          */
 179 #define SKIPPED 1
 180
 181         flags = FTS_PHYSICAL;
 182         if (!needstat)
 183                 flags |= FTS_NOSTAT;
 184         if (Wflag)
 185                 flags |= FTS_WHITEOUT;
 186         if (!(fts = fts_open(argv, flags, NULL)))
 187                 err(1, NULL);
 188         while ((p = fts_read(fts)) != NULL) {
 189                 switch (p->fts_info) {
 190                 case FTS_DNR:
 191                         if (!fflag || p->fts_errno != ENOENT) {
 192                                 warnx("%s: %s",
 193                                     p->fts_path, strerror(p->fts_errno));
 194                                 eval = 1;
 195                         }
 196                         continue;
 197                 case FTS_ERR:
 198                         errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
 199                 case FTS_NS:
 200                         /*
 201                          * FTS_NS: assume that if can't stat the file, it
 202                          * can't be unlinked.
 203                          */
 204                         if (!needstat)
 205                                 break;
 206                         if (!fflag || p->fts_errno != ENOENT) {
 207                                 warnx("%s: %s",
 208                                     p->fts_path, strerror(p->fts_errno));
 209                                 eval = 1;
 210                         }
 211                         continue;
 212                 case FTS_D:
 213                         /* Pre-order: give user chance to skip. */
 214                         if (!fflag && !check(p->fts_path, p->fts_accpath,
 215                             p->fts_statp)) {
 216                                 (void)fts_set(fts, p, FTS_SKIP);
 217                                 p->fts_number = SKIPPED;
 218                         }
 219                         else if (!uid &&
 220                                  (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 221                                  !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 222                                  chflags(p->fts_accpath,
 223                                          p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
 224                                 goto err;
 225                         continue;
 226                 case FTS_DP:
 227                         /* Post-order: see if user skipped. */
 228                         if (p->fts_number == SKIPPED)
 229                                 continue;
 230                         break;
 231                 default:
 232                         if (!fflag &&
 233                             !check(p->fts_path, p->fts_accpath, p->fts_statp))
 234                                 continue;
 235                 }
 236
 237                 rval = 0;
 238                 if (!uid &&
 239                     (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 240                     !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
 241                         rval = chflags(p->fts_accpath,
 242                                        p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
 243                 if (rval == 0) {
 244                         /*
 245                          * If we can't read or search the directory, may still be
 246                          * able to remove it.  Don't print out the un{read,search}able
 247                          * message unless the remove fails.
 248                          */
 249                         switch (p->fts_info) {
 250                         case FTS_DP:
 251                         case FTS_DNR:
 252                                 rval = rmdir(p->fts_accpath);
 253                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 254                                         if (rval == 0 && vflag)
 255                                                 (void)printf("%s\n",
 256                                                     p->fts_path);
 257                                         continue;
 258                                 }
 259                                 break;
 260
 261                         case FTS_W:
 262                                 rval = undelete(p->fts_accpath);
 263                                 if (rval == 0 && (fflag && errno == ENOENT)) {
 264                                         if (vflag)
 265                                                 (void)printf("%s\n",
 266                                                     p->fts_path);
 267                                         continue;
 268                                 }
 269                                 break;
 270
 271                         default:
 272                                 if (Pflag)
 273                                         rm_overwrite(p->fts_accpath, NULL);
 274                                 rval = unlink(p->fts_accpath);
 275                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 276                                         if (rval == 0 && vflag)
 277                                                 (void)printf("%s\n",
 278                                                     p->fts_path);
 279                                         continue;
 280                                 }
 281                         }
 282                 }
 283 err:
 284                 warn("%s", p->fts_path);
 285                 eval = 1;
 286         }
 287         if (errno)
 288                 err(1, "fts_read");
 289 }
 290
 291 void
 292 rm_file(argv)
 293         char **argv;
 294 {
 295         struct stat sb;
 296         int rval;
 297         char *f;
 298
 299         /*
 300          * Remove a file.  POSIX 1003.2 states that, by default, attempting
 301          * to remove a directory is an error, so must always stat the file.
 302          */
 303         while ((f = *argv++) != NULL) {
 304                 /* Assume if can't stat the file, can't unlink it. */
 305                 if (lstat(f, &sb)) {
 306                         if (Wflag) {
 307                                 sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
 308                         } else {
 309                                 if (!fflag || errno != ENOENT) {
 310                                         warn("%s", f);
 311                                         eval = 1;
 312                                 }
 313                                 continue;
 314                         }
 315                 } else if (Wflag) {
 316                         warnx("%s: %s", f, strerror(EEXIST));
 317                         eval = 1;
 318                         continue;
 319                 }
 320
 321                 if (S_ISDIR(sb.st_mode) && !dflag) {
 322                         warnx("%s: is a directory", f);
 323                         eval = 1;
 324                         continue;
 325                 }
 326                 if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
 327                         continue;
 328                 rval = 0;
 329                 if (!uid &&
 330                     (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 331                     !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
 332                         rval = chflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
 333                 if (rval == 0) {
 334                         if (S_ISWHT(sb.st_mode))
 335                                 rval = undelete(f);
 336                         else if (S_ISDIR(sb.st_mode))
 337                                 rval = rmdir(f);
 338                         else {
 339                                 if (Pflag)
 340                                         rm_overwrite(f, &sb);
 341                                 rval = unlink(f);
 342                         }
 343                 }
 344                 if (rval && (!fflag || errno != ENOENT)) {
 345                         warn("%s", f);
 346                         eval = 1;
 347                 }
 348                 if (vflag && rval == 0)
 349                         (void)printf("%s\n", f);
 350         }
 351 }
 352
 353 /*
 354  * rm_overwrite --
 355  *      Overwrite the file 3 times with varying bit patterns.
 356  *
 357  * XXX
 358  * This is a cheap way to *really* delete files.  Note that only regular
 359  * files are deleted, directories (and therefore names) will remain.
 360  * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
 361  * System V file system).  In a logging file system, you'll have to have
 362  * kernel support.
 363  */
 364 void
 365 rm_overwrite(file, sbp)
 366         char *file;
 367         struct stat *sbp;
 368 {
 369         struct stat sb;
 370         struct statfs fsb;
 371         off_t len;
 372         int bsize, fd, wlen;
 373         char *buf = NULL;
 374
 375         fd = -1;
 376         if (sbp == NULL) {
 377                 if (lstat(file, &sb))
 378                         goto err;
 379                 sbp = &sb;
 380         }
 381         if (!S_ISREG(sbp->st_mode))
 382                 return;
 383         if ((fd = open(file, O_WRONLY, 0)) == -1)
 384                 goto err;
 385         if (fstatfs(fd, &fsb) == -1)
 386                 goto err;
 387         bsize = MAX(fsb.f_iosize, 1024);
 388         if ((buf = malloc(bsize)) == NULL)
 389                 err(1, "malloc");
 390
 391 #define PASS(byte) {                                                    \
 392         memset(buf, byte, bsize);                                       \
 393         for (len = sbp->st_size; len > 0; len -= wlen) {                \
 394                 wlen = len < bsize ? len : bsize;                       \
 395                 if (write(fd, buf, wlen) != wlen)                       \
 396                         goto err;                                       \
 397         }                                                               \
 398 }
 399         PASS(0xff);
 400         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 401                 goto err;
 402         PASS(0x00);
 403         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 404                 goto err;
 405         PASS(0xff);
 406         if (!fsync(fd) && !close(fd)) {
 407                 free(buf);
 408                 return;
 409         }
 410
 411 err:    eval = 1;
 412         if (buf)
 413                 free(buf);
 414         warn("%s", file);
 415 }
 416
 417
 418 int
 419 check(path, name, sp)
 420         char *path, *name;
 421         struct stat *sp;
 422 {
 423         int ch, first;
 424         char modep[15], *flagsp;
 425
 426         /* Check -i first. */
 427         if (iflag)
 428                 (void)fprintf(stderr, "remove %s? ", path);
 429         else {
 430                 /*
 431                  * If it's not a symbolic link and it's unwritable and we're
 432                  * talking to a terminal, ask.  Symbolic links are excluded
 433                  * because their permissions are meaningless.  Check stdin_ok
 434                  * first because we may not have stat'ed the file.
 435                  */
 436                 if (!stdin_ok || S_ISLNK(sp->st_mode) ||
 437                     (!access(name, W_OK) &&
 438                     !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 439                     (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
 440                         return (1);
 441                 strmode(sp->st_mode, modep);
 442                 if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
 443                         err(1, NULL);
 444                 (void)fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
 445                     modep + 1, modep[9] == ' ' ? "" : " ",
 446                     user_from_uid(sp->st_uid, 0),
 447                     group_from_gid(sp->st_gid, 0),
 448                     *flagsp ? flagsp : "", *flagsp ? " " : "",
 449                     path);
 450                 free(flagsp);
 451         }
 452         (void)fflush(stderr);
 453
 454         first = ch = getchar();
 455         while (ch != '\n' && ch != EOF)
 456                 ch = getchar();
 457         return (first == 'y' || first == 'Y');
 458 }
 459
 460 #define ISDOT(a)        ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
 461 void
 462 checkdot(argv)
 463         char **argv;
 464 {
 465         char *p, **save, **t;
 466         int complained;
 467
 468         complained = 0;
 469         for (t = argv; *t;) {
 470                 if ((p = strrchr(*t, '/')) != NULL)
 471                         ++p;
 472                 else
 473                         p = *t;
 474                 if (ISDOT(p)) {
 475                         if (!complained++)
 476                                 warnx("\".\" and \"..\" may not be removed");
 477                         eval = 1;
 478                         for (save = t; (t[0] = t[1]) != NULL; ++t)
 479                                 continue;
 480                         t = save;
 481                 } else
 482                         ++t;
 483         }
 484 }
 485
 486 void
 487 usage()
 488 {
 489
 490         (void)fprintf(stderr, "%s\n%s\n",
 491             "usage: rm [-f | -i] [-dPRrvW] file ...",
 492             "       unlink file");
 493         exit(EX_USAGE);
 494 }