bin/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  * @(#) Copyright (c) 1990, 1993, 1994 The Regents of the University of California.  All rights reserved.
  34  * @(#)rm.c     8.5 (Berkeley) 4/18/94
  35  * $FreeBSD: src/bin/rm/rm.c,v 1.29.2.5 2002/07/12 07:25:48 tjr Exp $
  36  * $DragonFly: src/bin/rm/rm.c,v 1.15 2005/09/22 01:49:44 corecode Exp $
  37  */
  38
  39 #include <sys/stat.h>
  40 #include <sys/param.h>
  41 #include <sys/mount.h>
  42 #include <sys/ioctl.h>
  43
  44 #include <err.h>
  45 #include <errno.h>
  46 #include <fcntl.h>
  47 #include <fts.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51 #include <sysexits.h>
  52 #include <unistd.h>
  53
  54 int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
  55 int rflag, Iflag;
  56 uid_t uid;
  57
  58 static int      check(const char *, const char *, struct stat *);
  59 static int      check2(char **);
  60 static void     checkdot(char **);
  61 static void     rm_file(char **);
  62 static int      rm_overwrite(const char *, struct stat *);
  63 static void     rm_tree(char **);
  64 static void     usage(void);
  65
  66 /*
  67  * rm --
  68  *      This rm is different from historic rm's, but is expected to match
  69  *      POSIX 1003.2 behavior.  The most visible difference is that -f
  70  *      has two specific effects now, ignore non-existent files and force
  71  *      file removal.
  72  */
  73 int
  74 main(int argc, char *argv[])
  75 {
  76         int ch;
  77         const char *p;
  78         pid_t tty_pgrp;
  79
  80         /*
  81          * Test for the special case where the utility is called as
  82          * "unlink", for which the functionality provided is greatly
  83          * simplified.
  84          */
  85         if ((p = strrchr(argv[0], '/')) == NULL)
  86                 p = argv[0];
  87         else
  88                 ++p;
  89         if (strcmp(p, "unlink") == 0) {
  90                 while (getopt(argc, argv, "") != -1)
  91                         usage();
  92                 argc -= optind;
  93                 argv += optind;
  94                 if (argc != 1)
  95                         usage();
  96                 rm_file(&argv[0]);
  97                 exit(eval);
  98         }
  99
 100         Pflag = rflag = 0;
 101         while ((ch = getopt(argc, argv, "dfiIPRrvW")) != -1) {
 102                 switch(ch) {
 103                 case 'd':
 104                         dflag = 1;
 105                         break;
 106                 case 'f':
 107                         fflag = 1;
 108                         iflag = 0;
 109                         break;
 110                 case 'i':
 111                         fflag = 0;
 112                         iflag = 1;
 113                         break;
 114                 case 'I':
 115                         /*
 116                          * The -I flag is intended to be generally aliasable
 117                          * in /etc/csh.cshrc.  We apply it only to foreground
 118                          * processes.
 119                          */
 120                         if (ioctl(0, TIOCGPGRP, &tty_pgrp) == 0) {
 121                                 if (tty_pgrp == getpgrp())
 122                                         Iflag = 1;
 123                         }
 124                         break;
 125                 case 'P':
 126                         Pflag = 1;
 127                         break;
 128                 case 'R':
 129                 case 'r':                       /* Compatibility. */
 130                         rflag = 1;
 131                         break;
 132                 case 'v':
 133                         vflag = 1;
 134                         break;
 135                 case 'W':
 136                         Wflag = 1;
 137                         break;
 138                 default:
 139                         usage();
 140                 }
 141         }
 142         argc -= optind;
 143         argv += optind;
 144
 145         if (argc < 1) {
 146                 if (fflag)
 147                         return 0;
 148                 usage();
 149         }
 150
 151         checkdot(argv);
 152         uid = geteuid();
 153
 154         if (*argv) {
 155                 stdin_ok = isatty(STDIN_FILENO);
 156
 157                 if (Iflag && !iflag) {
 158                         if (check2(argv) == 0)
 159                                 exit (1);
 160                 }
 161                 if (rflag)
 162                         rm_tree(argv);
 163                 else
 164                         rm_file(argv);
 165         }
 166
 167         exit (eval);
 168 }
 169
 170 static void
 171 rm_tree(char **argv)
 172 {
 173         FTS *fts;
 174         FTSENT *p;
 175         int needstat;
 176         int flags;
 177         int rval;
 178
 179         /*
 180          * Remove a file hierarchy.  If forcing removal (-f), or interactive
 181          * (-i) or can't ask anyway (stdin_ok), don't stat the file.
 182          */
 183         needstat = !uid || (!fflag && !iflag && stdin_ok);
 184
 185         /*
 186          * If the -i option is specified, the user can skip on the pre-order
 187          * visit.  The fts_number field flags skipped directories.
 188          */
 189 #define SKIPPED 1
 190
 191         flags = FTS_PHYSICAL;
 192         if (!needstat)
 193                 flags |= FTS_NOSTAT;
 194         if (Wflag)
 195                 flags |= FTS_WHITEOUT;
 196         if ((fts = fts_open(argv, flags, NULL)) == NULL) {
 197                 if (fflag && errno == ENOENT)
 198                         return;
 199                 err(1, NULL);
 200         }
 201         while ((p = fts_read(fts)) != NULL) {
 202                 switch (p->fts_info) {
 203                 case FTS_DNR:
 204                         if (!fflag || p->fts_errno != ENOENT) {
 205                                 warnx("%s: %s",
 206                                     p->fts_path, strerror(p->fts_errno));
 207                                 eval = 1;
 208                         }
 209                         continue;
 210                 case FTS_ERR:
 211                         errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
 212                 case FTS_NS:
 213                        /*
 214                         * Assume that since fts_read() couldn't stat
 215                         * the file, it can't be unlinked.
 216                         */
 217                         if (!needstat)
 218                                 break;
 219                         if (!fflag || p->fts_errno != ENOENT) {
 220                                 warnx("%s: %s",
 221                                     p->fts_path, strerror(p->fts_errno));
 222                                 eval = 1;
 223                         }
 224                         continue;
 225                 case FTS_D:
 226                         /* Pre-order: give user chance to skip. */
 227                         if (!fflag && !check(p->fts_path, p->fts_accpath,
 228                             p->fts_statp)) {
 229                                 fts_set(fts, p, FTS_SKIP);
 230                                 p->fts_number = SKIPPED;
 231                         }
 232                         else if (!uid &&
 233                                  (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 234                                  !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 235                                  chflags(p->fts_accpath,
 236                                          p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
 237                                 goto err;
 238                         continue;
 239                 case FTS_DP:
 240                         /* Post-order: see if user skipped. */
 241                         if (p->fts_number == SKIPPED)
 242                                 continue;
 243                         break;
 244                 default:
 245                         if (!fflag &&
 246                             !check(p->fts_path, p->fts_accpath, p->fts_statp))
 247                                 continue;
 248                 }
 249
 250                 rval = 0;
 251                 if (!uid &&
 252                     (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 253                     !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
 254                         rval = chflags(p->fts_accpath,
 255                                        p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
 256                 if (rval == 0) {
 257                         /*
 258                          * If we can't read or search the directory, may still be
 259                          * able to remove it.  Don't print out the un{read,search}able
 260                          * message unless the remove fails.
 261                          */
 262                         switch (p->fts_info) {
 263                         case FTS_DP:
 264                         case FTS_DNR:
 265                                 rval = rmdir(p->fts_accpath);
 266                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 267                                         if (rval == 0 && vflag)
 268                                                 printf("%s\n",
 269                                                     p->fts_path);
 270                                         continue;
 271                                 }
 272                                 break;
 273
 274                         case FTS_W:
 275                                 rval = undelete(p->fts_accpath);
 276                                 if (rval == 0 && (fflag && errno == ENOENT)) {
 277                                         if (vflag)
 278                                                 printf("%s\n",
 279                                                     p->fts_path);
 280                                         continue;
 281                                 }
 282                                 break;
 283
 284                         case FTS_NS:
 285                         /*
 286                          * Assume that since fts_read() couldn't stat
 287                          * the file, it can't be unlinked.
 288                          */
 289                                 if (fflag)
 290                                         continue;
 291                                 /* FALLTHROUGH */
 292                         default:
 293                                 if (Pflag)
 294                                         if (!rm_overwrite(p->fts_accpath, NULL))
 295                                                 continue;
 296                                 rval = unlink(p->fts_accpath);
 297                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 298                                         if (rval == 0 && vflag)
 299                                                 printf("%s\n",
 300                                                     p->fts_path);
 301                                         continue;
 302                                 }
 303                         }
 304                 }
 305 err:
 306                 warn("%s", p->fts_path);
 307                 eval = 1;
 308         }
 309         if (errno)
 310                 err(1, "fts_read");
 311 }
 312
 313 static void
 314 rm_file(char **argv)
 315 {
 316         struct stat sb;
 317         int rval;
 318         const char *f;
 319
 320         /*
 321          * Remove a file.  POSIX 1003.2 states that, by default, attempting
 322          * to remove a directory is an error, so must always stat the file.
 323          */
 324         while ((f = *argv++) != NULL) {
 325                 /* Assume if can't stat the file, can't unlink it. */
 326                 if (lstat(f, &sb)) {
 327                         if (Wflag) {
 328                                 sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
 329                         } else {
 330                                 if (!fflag || errno != ENOENT) {
 331                                         warn("%s", f);
 332                                         eval = 1;
 333                                 }
 334                                 continue;
 335                         }
 336                 } else if (Wflag) {
 337                         warnx("%s: %s", f, strerror(EEXIST));
 338                         eval = 1;
 339                         continue;
 340                 }
 341
 342                 if (S_ISDIR(sb.st_mode) && !dflag) {
 343                         warnx("%s: is a directory", f);
 344                         eval = 1;
 345                         continue;
 346                 }
 347                 if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
 348                         continue;
 349                 rval = 0;
 350                 if (!uid &&
 351                     (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 352                     !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
 353                         rval = chflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
 354                 if (rval == 0) {
 355                         if (S_ISWHT(sb.st_mode))
 356                                 rval = undelete(f);
 357                         else if (S_ISDIR(sb.st_mode))
 358                                 rval = rmdir(f);
 359                         else {
 360                                 if (Pflag)
 361                                         if (!rm_overwrite(f, &sb))
 362                                                 continue;
 363                                 rval = unlink(f);
 364                         }
 365                 }
 366                 if (rval && (!fflag || errno != ENOENT)) {
 367                         warn("%s", f);
 368                         eval = 1;
 369                 }
 370                 if (vflag && rval == 0)
 371                         printf("%s\n", f);
 372         }
 373 }
 374
 375 /*
 376  * rm_overwrite --
 377  *      Overwrite the file 3 times with varying bit patterns.
 378  *
 379  * XXX
 380  * This is a cheap way to *really* delete files.  Note that only regular
 381  * files are deleted, directories (and therefore names) will remain.
 382  * Also, this assumes a fixed-block filesystem (like FFS, or a V7 or a
 383  * System V filesystem).  In a logging filesystem, you'll have to have
 384  * kernel support.
 385  */
 386 static int
 387 rm_overwrite(const char *file, struct stat *sbp)
 388 {
 389         struct stat sb;
 390         struct statfs fsb;
 391         off_t len;
 392         int bsize, fd, wlen;
 393         char *buf = NULL;
 394
 395         fd = -1;
 396         if (sbp == NULL) {
 397                 if (lstat(file, &sb))
 398                         goto err;
 399                 sbp = &sb;
 400         }
 401         if (!S_ISREG(sbp->st_mode)) {
 402                 warnx("%s: cannot overwrite a non-regular file", file);
 403                 return (1);
 404         }
 405         if ((fd = open(file, O_WRONLY, 0)) == -1)
 406                 goto err;
 407         if (fstatfs(fd, &fsb) == -1)
 408                 goto err;
 409         bsize = MAX(fsb.f_iosize, 1024);
 410         if ((buf = malloc(bsize)) == NULL)
 411                 err(1, "%s malloc failed", file);
 412
 413 #define PASS(byte) {                                                    \
 414         memset(buf, byte, bsize);                                       \
 415         for (len = sbp->st_size; len > 0; len -= wlen) {                \
 416                 wlen = len < bsize ? len : bsize;                       \
 417                 if (write(fd, buf, wlen) != wlen)                       \
 418                         goto err;                                       \
 419         }                                                               \
 420 }
 421         PASS(0xff);
 422         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 423                 goto err;
 424         PASS(0x00);
 425         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 426                 goto err;
 427         PASS(0xff);
 428         if (!fsync(fd) && !close(fd)) {
 429                 free(buf);
 430                 return (1);
 431         }
 432
 433 err:    eval = 1;
 434         if (buf)
 435                 free(buf);
 436         if (fd != -1)
 437                 close(fd);
 438         warn("%s", file);
 439         return (0);
 440 }
 441
 442
 443 static int
 444 check(const char *path, const char *name, struct stat *sp)
 445 {
 446         static int perm_answer = -1;
 447         struct choice {
 448                 int ch;
 449                 const char *str;
 450                 int res;
 451                 int perm;
 452         } *choice, choices[] = {
 453                 { 'y', "yes"   , 1, 0 },
 454                 { 'n', "no"    , 0, 0 },
 455                 { 'a', "always", 1, 1 },
 456                 { 'v', "never" , 0, 1 },
 457                 { 0, NULL, 0, 0 }
 458         };
 459         char modep[15], *flagsp;
 460
 461         if (perm_answer != -1)
 462                 return (perm_answer);
 463
 464         /* Check -i first. */
 465         if (iflag)
 466                 fprintf(stderr, "remove %s? ", path);
 467         else {
 468                 /*
 469                  * If it's not a symbolic link and it's unwritable and we're
 470                  * talking to a terminal, ask.  Symbolic links are excluded
 471                  * because their permissions are meaningless.  Check stdin_ok
 472                  * first because we may not have stat'ed the file.
 473                  * Also skip this check if the -P option was specified because
 474                  * we will not be able to overwrite file contents and will
 475                  * barf later.
 476                  */
 477                 if (!stdin_ok || S_ISLNK(sp->st_mode) || Pflag ||
 478                     (!access(name, W_OK) &&
 479                     !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 480                     (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
 481                         return (1);
 482                 strmode(sp->st_mode, modep);
 483                 if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
 484                         err(1, NULL);
 485                 fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
 486                     modep + 1, modep[9] == ' ' ? "" : " ",
 487                     user_from_uid(sp->st_uid, 0),
 488                     group_from_gid(sp->st_gid, 0),
 489                     *flagsp ? flagsp : "", *flagsp ? " " : "",
 490                     path);
 491                 free(flagsp);
 492         }
 493         fflush(stderr);
 494
 495         for (;;) {
 496                 size_t len;
 497                 char *answer;
 498
 499                 answer = fgetln(stdin, &len);
 500                 /* clearerr(stdin); */
 501                 if (answer == NULL)
 502                         return (0);
 503                 if (answer[len - 1] == '\n')
 504                         len--;
 505                 if (len == 0)
 506                         continue;
 507
 508                 for (choice = choices; choice->str != NULL; choice++) {
 509                         if (len == 1 && choice->ch == answer[0])
 510                                 goto valid_choice;
 511                         if (strncasecmp(answer, choice->str, len) == 0)
 512                                 goto valid_choice;
 513                 }
 514
 515                 fprintf(stderr, "invalid answer, try again (y/n/a/v): ");
 516         }
 517
 518 valid_choice:
 519         if (choice->perm)
 520                 perm_answer = choice->res;
 521         return (choice->res);
 522 }
 523
 524 static int
 525 check2(char **argv)
 526 {
 527         struct stat st;
 528         int first;
 529         int ch;
 530         int fcount = 0;
 531         int dcount = 0;
 532         int i;
 533         const char *dname = NULL;
 534
 535         for (i = 0; argv[i]; ++i) {
 536                 if (lstat(argv[i], &st) == 0) {
 537                         if (S_ISDIR(st.st_mode)) {
 538                                 ++dcount;
 539                                 dname = argv[i];    /* only used if 1 dir */
 540                         } else {
 541                                 ++fcount;
 542                         }
 543                 }
 544         }
 545         first = 0;
 546         while (first != 'n' && first != 'N' && first != 'y' && first != 'Y') {
 547                 if (dcount && rflag) {
 548                         fprintf(stderr, "recursively remove");
 549                         if (dcount == 1)
 550                                 fprintf(stderr, " %s", dname);
 551                         else
 552                                 fprintf(stderr, " %d dirs", dcount);
 553                         if (fcount == 1)
 554                                 fprintf(stderr, " and 1 file");
 555                         else if (fcount > 1)
 556                                 fprintf(stderr, " and %d files", fcount);
 557                 } else if (dcount + fcount > 3) {
 558                         fprintf(stderr, "remove %d files", dcount + fcount);
 559                 } else {
 560                         return(1);
 561                 }
 562                 fprintf(stderr, "? ");
 563                 fflush(stderr);
 564
 565                 first = ch = getchar();
 566                 while (ch != '\n' && ch != EOF)
 567                         ch = getchar();
 568                 if (ch == EOF)
 569                         break;
 570         }
 571         return (first == 'y' || first == 'Y');
 572 }
 573
 574 #define ISDOT(a)        ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
 575 static void
 576 checkdot(char **argv)
 577 {
 578         char *p, **save, **t;
 579         int complained;
 580
 581         complained = 0;
 582         for (t = argv; *t;) {
 583                 if ((p = strrchr(*t, '/')) != NULL)
 584                         ++p;
 585                 else
 586                         p = *t;
 587                 if (ISDOT(p)) {
 588                         if (!complained++)
 589                                 warnx("\".\" and \"..\" may not be removed");
 590                         eval = 1;
 591                         for (save = t; (t[0] = t[1]) != NULL; ++t)
 592                                 continue;
 593                         t = save;
 594                 } else
 595                         ++t;
 596         }
 597 }
 598
 599 static void
 600 usage(void)
 601 {
 602
 603         fprintf(stderr, "%s\n%s\n",
 604             "usage: rm [-f | -i] [-dIPRrvW] file ...",
 605             "       unlink file");
 606         exit(EX_USAGE);
 607 }