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 #ifdef __APPLE__
  74 /* We lack fflagstostr(), but ls has a flags_to_string function
  75  * that does the same thing.  So...  We really use that.
  76  */
  77 char * flags_to_string(u_long, char *);
  78 #define fflagstostr(x) flags_to_string((x), NULL)
  79
  80 #endif
  81
  82 /*
  83  * rm --
  84  *      This rm is different from historic rm's, but is expected to match
  85  *      POSIX 1003.2 behavior.  The most visible difference is that -f
  86  *      has two specific effects now, ignore non-existent files and force
  87  *      file removal.
  88  */
  89 int
  90 main(argc, argv)
  91         int argc;
  92         char *argv[];
  93 {
  94         int ch, rflag;
  95         char *p;
  96
  97         /*
  98          * Test for the special case where the utility is called as
  99          * "unlink", for which the functionality provided is greatly
 100          * simplified.
 101          */
 102         if ((p = rindex(argv[0], '/')) == NULL)
 103                 p = argv[0];
 104         else
 105                 ++p;
 106         if (strcmp(p, "unlink") == 0) {
 107                 if (argc == 2) {
 108                         rm_file(&argv[1]);
 109                         exit(eval);
 110                 } else
 111                         usage();
 112         }
 113
 114         Pflag = rflag = 0;
 115         while ((ch = getopt(argc, argv, "dfiPRrvW")) != -1)
 116                 switch(ch) {
 117                 case 'd':
 118                         dflag = 1;
 119                         break;
 120                 case 'f':
 121                         fflag = 1;
 122                         iflag = 0;
 123                         break;
 124                 case 'i':
 125                         fflag = 0;
 126                         iflag = 1;
 127                         break;
 128                 case 'P':
 129                         Pflag = 1;
 130                         break;
 131                 case 'R':
 132                 case 'r':                       /* Compatibility. */
 133                         rflag = 1;
 134                         break;
 135                 case 'v':
 136                         vflag = 1;
 137                         break;
 138                 case 'W':
 139                         Wflag = 1;
 140                         break;
 141                 default:
 142                         usage();
 143                 }
 144         argc -= optind;
 145         argv += optind;
 146
 147         if (argc < 1) {
 148                 if (fflag)
 149                         return 0;
 150                 usage();
 151         }
 152
 153         checkdot(argv);
 154         uid = geteuid();
 155
 156         if (*argv) {
 157                 stdin_ok = isatty(STDIN_FILENO);
 158
 159                 if (rflag)
 160                         rm_tree(argv);
 161                 else
 162                         rm_file(argv);
 163         }
 164
 165         exit (eval);
 166 }
 167
 168 void
 169 rm_tree(argv)
 170         char **argv;
 171 {
 172         FTS *fts;
 173         FTSENT *p;
 174         int needstat;
 175         int flags;
 176         int rval;
 177
 178         /*
 179          * Remove a file hierarchy.  If forcing removal (-f), or interactive
 180          * (-i) or can't ask anyway (stdin_ok), don't stat the file.
 181          */
 182         needstat = !uid || (!fflag && !iflag && stdin_ok);
 183
 184         /*
 185          * If the -i option is specified, the user can skip on the pre-order
 186          * visit.  The fts_number field flags skipped directories.
 187          */
 188 #define SKIPPED 1
 189
 190         flags = FTS_PHYSICAL;
 191         if (!needstat)
 192                 flags |= FTS_NOSTAT;
 193         if (Wflag)
 194                 flags |= FTS_WHITEOUT;
 195         if (!(fts = fts_open(argv, flags, NULL)))
 196                 err(1, NULL);
 197         while ((p = fts_read(fts)) != NULL) {
 198                 switch (p->fts_info) {
 199                 case FTS_DNR:
 200                         if (!fflag || p->fts_errno != ENOENT) {
 201                                 warnx("%s: %s",
 202                                     p->fts_path, strerror(p->fts_errno));
 203                                 eval = 1;
 204                         }
 205                         continue;
 206                 case FTS_ERR:
 207                         errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
 208                 case FTS_NS:
 209                         /*
 210                          * FTS_NS: assume that if can't stat the file, it
 211                          * can't be unlinked.
 212                          */
 213                         if (!needstat)
 214                                 break;
 215                         if (!fflag || p->fts_errno != ENOENT) {
 216                                 warnx("%s: %s",
 217                                     p->fts_path, strerror(p->fts_errno));
 218                                 eval = 1;
 219                         }
 220                         continue;
 221                 case FTS_D:
 222                         /* Pre-order: give user chance to skip. */
 223                         if (!fflag && !check(p->fts_path, p->fts_accpath,
 224                             p->fts_statp)) {
 225                                 (void)fts_set(fts, p, FTS_SKIP);
 226                                 p->fts_number = SKIPPED;
 227                         }
 228                         else if (!uid &&
 229                                  (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 230                                  !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 231                                  chflags(p->fts_accpath,
 232                                          p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
 233                                 goto err;
 234                         continue;
 235                 case FTS_DP:
 236                         /* Post-order: see if user skipped. */
 237                         if (p->fts_number == SKIPPED)
 238                                 continue;
 239                         break;
 240                 default:
 241                         if (!fflag &&
 242                             !check(p->fts_path, p->fts_accpath, p->fts_statp))
 243                                 continue;
 244                 }
 245
 246                 rval = 0;
 247                 if (!uid &&
 248                     (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 249                     !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
 250                         rval = chflags(p->fts_accpath,
 251                                        p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
 252                 if (rval == 0) {
 253                         /*
 254                          * If we can't read or search the directory, may still be
 255                          * able to remove it.  Don't print out the un{read,search}able
 256                          * message unless the remove fails.
 257                          */
 258                         switch (p->fts_info) {
 259                         case FTS_DP:
 260                         case FTS_DNR:
 261                                 rval = rmdir(p->fts_accpath);
 262                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 263                                         if (rval == 0 && vflag)
 264                                                 (void)printf("%s\n",
 265                                                     p->fts_path);
 266                                         continue;
 267                                 }
 268                                 break;
 269
 270                         case FTS_W:
 271                                 rval = undelete(p->fts_accpath);
 272                                 if (rval == 0 && (fflag && errno == ENOENT)) {
 273                                         if (vflag)
 274                                                 (void)printf("%s\n",
 275                                                     p->fts_path);
 276                                         continue;
 277                                 }
 278                                 break;
 279
 280                         default:
 281                                 if (Pflag)
 282                                         rm_overwrite(p->fts_accpath, NULL);
 283                                 rval = unlink(p->fts_accpath);
 284                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 285                                         if (rval == 0 && vflag)
 286                                                 (void)printf("%s\n",
 287                                                     p->fts_path);
 288                                         continue;
 289                                 }
 290                         }
 291                 }
 292 err:
 293                 warn("%s", p->fts_path);
 294                 eval = 1;
 295         }
 296         if (errno)
 297                 err(1, "fts_read");
 298 }
 299
 300 void
 301 rm_file(argv)
 302         char **argv;
 303 {
 304         struct stat sb;
 305         int rval;
 306         char *f;
 307
 308         /*
 309          * Remove a file.  POSIX 1003.2 states that, by default, attempting
 310          * to remove a directory is an error, so must always stat the file.
 311          */
 312         while ((f = *argv++) != NULL) {
 313                 /* Assume if can't stat the file, can't unlink it. */
 314                 if (lstat(f, &sb)) {
 315                         if (Wflag) {
 316                                 sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
 317                         } else {
 318                                 if (!fflag || errno != ENOENT) {
 319                                         warn("%s", f);
 320                                         eval = 1;
 321                                 }
 322                                 continue;
 323                         }
 324                 } else if (Wflag) {
 325                         warnx("%s: %s", f, strerror(EEXIST));
 326                         eval = 1;
 327                         continue;
 328                 }
 329
 330                 if (S_ISDIR(sb.st_mode) && !dflag) {
 331                         warnx("%s: is a directory", f);
 332                         eval = 1;
 333                         continue;
 334                 }
 335                 if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
 336                         continue;
 337                 rval = 0;
 338                 if (!uid &&
 339                     (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 340                     !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
 341                         rval = chflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
 342                 if (rval == 0) {
 343                         if (S_ISWHT(sb.st_mode))
 344                                 rval = undelete(f);
 345                         else if (S_ISDIR(sb.st_mode))
 346                                 rval = rmdir(f);
 347                         else {
 348                                 if (Pflag)
 349                                         rm_overwrite(f, &sb);
 350                                 rval = unlink(f);
 351                         }
 352                 }
 353                 if (rval && (!fflag || errno != ENOENT)) {
 354                         warn("%s", f);
 355                         eval = 1;
 356                 }
 357                 if (vflag && rval == 0)
 358                         (void)printf("%s\n", f);
 359         }
 360 }
 361
 362 /*
 363  * rm_overwrite --
 364  *      Overwrite the file 3 times with varying bit patterns.
 365  *
 366  * XXX
 367  * This is a cheap way to *really* delete files.  Note that only regular
 368  * files are deleted, directories (and therefore names) will remain.
 369  * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
 370  * System V file system).  In a logging file system, you'll have to have
 371  * kernel support.
 372  */
 373 void
 374 rm_overwrite(file, sbp)
 375         char *file;
 376         struct stat *sbp;
 377 {
 378         struct stat sb;
 379         struct statfs fsb;
 380         off_t len;
 381         int bsize, fd, wlen;
 382         char *buf = NULL;
 383
 384         fd = -1;
 385         if (sbp == NULL) {
 386                 if (lstat(file, &sb))
 387                         goto err;
 388                 sbp = &sb;
 389         }
 390         if (!S_ISREG(sbp->st_mode))
 391                 return;
 392         if ((fd = open(file, O_WRONLY, 0)) == -1)
 393                 goto err;
 394         if (fstatfs(fd, &fsb) == -1)
 395                 goto err;
 396         bsize = MAX(fsb.f_iosize, 1024);
 397         if ((buf = malloc(bsize)) == NULL)
 398                 err(1, "malloc");
 399
 400 #define PASS(byte) {                                                    \
 401         memset(buf, byte, bsize);                                       \
 402         for (len = sbp->st_size; len > 0; len -= wlen) {                \
 403                 wlen = len < bsize ? len : bsize;                       \
 404                 if (write(fd, buf, wlen) != wlen)                       \
 405                         goto err;                                       \
 406         }                                                               \
 407 }
 408         PASS(0xff);
 409         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 410                 goto err;
 411         PASS(0x00);
 412         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 413                 goto err;
 414         PASS(0xff);
 415         if (!fsync(fd) && !close(fd)) {
 416                 free(buf);
 417                 return;
 418         }
 419
 420 err:    eval = 1;
 421         if (buf)
 422                 free(buf);
 423         warn("%s", file);
 424 }
 425
 426
 427 int
 428 check(path, name, sp)
 429         char *path, *name;
 430         struct stat *sp;
 431 {
 432         int ch, first;
 433         char modep[15], *flagsp;
 434
 435         /* Check -i first. */
 436         if (iflag)
 437                 (void)fprintf(stderr, "remove %s? ", path);
 438         else {
 439                 /*
 440                  * If it's not a symbolic link and it's unwritable and we're
 441                  * talking to a terminal, ask.  Symbolic links are excluded
 442                  * because their permissions are meaningless.  Check stdin_ok
 443                  * first because we may not have stat'ed the file.
 444                  */
 445                 if (!stdin_ok || S_ISLNK(sp->st_mode) ||
 446                     (!access(name, W_OK) &&
 447                     !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 448                     (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
 449                         return (1);
 450                 strmode(sp->st_mode, modep);
 451                 if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
 452                         err(1, NULL);
 453                 (void)fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
 454                     modep + 1, modep[9] == ' ' ? "" : " ",
 455                     user_from_uid(sp->st_uid, 0),
 456                     group_from_gid(sp->st_gid, 0),
 457                     *flagsp ? flagsp : "", *flagsp ? " " : "",
 458                     path);
 459 #ifndef __APPLE__
 460                 free(flagsp);
 461 #endif
 462         }
 463         (void)fflush(stderr);
 464
 465         first = ch = getchar();
 466         while (ch != '\n' && ch != EOF)
 467                 ch = getchar();
 468         return (first == 'y' || first == 'Y');
 469 }
 470
 471 #define ISDOT(a)        ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
 472 void
 473 checkdot(argv)
 474         char **argv;
 475 {
 476         char *p, **save, **t;
 477         int complained;
 478
 479         complained = 0;
 480         for (t = argv; *t;) {
 481                 if ((p = strrchr(*t, '/')) != NULL)
 482                         ++p;
 483                 else
 484                         p = *t;
 485                 if (ISDOT(p)) {
 486                         if (!complained++)
 487                                 warnx("\".\" and \"..\" may not be removed");
 488                         eval = 1;
 489                         for (save = t; (t[0] = t[1]) != NULL; ++t)
 490                                 continue;
 491                         t = save;
 492                 } else
 493                         ++t;
 494         }
 495 }
 496
 497 void
 498 usage()
 499 {
 500
 501         (void)fprintf(stderr, "%s\n%s\n",
 502             "usage: rm [-f | -i] [-dPRrvW] file ...",
 503             "       unlink file");
 504         exit(EX_USAGE);
 505 }