rm.c revision 1.39 1 /* $NetBSD: rm.c,v 1.39 2004/01/04 16:04:18 jschauma Exp $ */
2
3 /*-
4 * Copyright (c) 1990, 1993, 1994, 2003
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 1990, 1993, 1994\n\
35 The Regents of the University of California. All rights reserved.\n");
36 #endif /* not lint */
37
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)rm.c 8.8 (Berkeley) 4/27/95";
41 #else
42 __RCSID("$NetBSD: rm.c,v 1.39 2004/01/04 16:04:18 jschauma Exp $");
43 #endif
44 #endif /* not lint */
45
46 #include <sys/param.h>
47 #include <sys/stat.h>
48 #include <sys/types.h>
49
50 #include <err.h>
51 #include <errno.h>
52 #include <fcntl.h>
53 #include <fts.h>
54 #include <grp.h>
55 #include <locale.h>
56 #include <pwd.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <unistd.h>
61
62 int dflag, eval, fflag, iflag, Pflag, stdin_ok, vflag, Wflag;
63
64 int check(char *, char *, struct stat *);
65 void checkdot(char **);
66 void rm_file(char **);
67 void rm_overwrite(char *, struct stat *);
68 void rm_tree(char **);
69 void usage(void);
70 int main(int, char *[]);
71
72 /*
73 * For the sake of the `-f' flag, check whether an error number indicates the
74 * failure of an operation due to an non-existent file, either per se (ENOENT)
75 * or because its filename argument was illegal (ENAMETOOLONG, ENOTDIR).
76 */
77 #define NONEXISTENT(x) \
78 ((x) == ENOENT || (x) == ENAMETOOLONG || (x) == ENOTDIR)
79
80 /*
81 * rm --
82 * This rm is different from historic rm's, but is expected to match
83 * POSIX 1003.2 behavior. The most visible difference is that -f
84 * has two specific effects now, ignore non-existent files and force
85 * file removal.
86 */
87 int
88 main(int argc, char *argv[])
89 {
90 int ch, rflag;
91
92 setprogname(argv[0]);
93 (void)setlocale(LC_ALL, "");
94
95 Pflag = rflag = 0;
96 while ((ch = getopt(argc, argv, "dfiPRrvW")) != -1)
97 switch (ch) {
98 case 'd':
99 dflag = 1;
100 break;
101 case 'f':
102 fflag = 1;
103 iflag = 0;
104 break;
105 case 'i':
106 fflag = 0;
107 iflag = 1;
108 break;
109 case 'P':
110 Pflag = 1;
111 break;
112 case 'R':
113 case 'r': /* Compatibility. */
114 rflag = 1;
115 break;
116 case 'v':
117 vflag = 1;
118 break;
119 case 'W':
120 Wflag = 1;
121 break;
122 case '?':
123 default:
124 usage();
125 }
126 argc -= optind;
127 argv += optind;
128
129 if (argc < 1)
130 usage();
131
132 checkdot(argv);
133
134 if (*argv) {
135 stdin_ok = isatty(STDIN_FILENO);
136
137 if (rflag)
138 rm_tree(argv);
139 else
140 rm_file(argv);
141 }
142
143 exit(eval);
144 /* NOTREACHED */
145 }
146
147 void
148 rm_tree(char **argv)
149 {
150 FTS *fts;
151 FTSENT *p;
152 int flags, needstat, rval;
153
154 /*
155 * Remove a file hierarchy. If forcing removal (-f), or interactive
156 * (-i) or can't ask anyway (stdin_ok), don't stat the file.
157 */
158 needstat = !fflag && !iflag && stdin_ok;
159
160 /*
161 * If the -i option is specified, the user can skip on the pre-order
162 * visit. The fts_number field flags skipped directories.
163 */
164 #define SKIPPED 1
165
166 flags = FTS_PHYSICAL;
167 if (!needstat)
168 flags |= FTS_NOSTAT;
169 if (Wflag)
170 flags |= FTS_WHITEOUT;
171 if (!(fts = fts_open(argv, flags,
172 (int (*)(const FTSENT **, const FTSENT **))NULL)))
173 err(1, NULL);
174 while ((p = fts_read(fts)) != NULL) {
175
176 switch (p->fts_info) {
177 case FTS_DNR:
178 if (!fflag || p->fts_errno != ENOENT) {
179 warnx("%s: %s", p->fts_path,
180 strerror(p->fts_errno));
181 eval = 1;
182 }
183 continue;
184 case FTS_ERR:
185 errx(EXIT_FAILURE, "%s: %s", p->fts_path,
186 strerror(p->fts_errno));
187 /* NOTREACHED */
188 case FTS_NS:
189 /*
190 * FTS_NS: assume that if can't stat the file, it
191 * can't be unlinked.
192 */
193 if (fflag && NONEXISTENT(p->fts_errno))
194 continue;
195 if (needstat) {
196 warnx("%s: %s", p->fts_path,
197 strerror(p->fts_errno));
198 eval = 1;
199 continue;
200 }
201 break;
202 case FTS_D:
203 /* Pre-order: give user chance to skip. */
204 if (!fflag && !check(p->fts_path, p->fts_accpath,
205 p->fts_statp)) {
206 (void)fts_set(fts, p, FTS_SKIP);
207 p->fts_number = SKIPPED;
208 }
209 continue;
210 case FTS_DP:
211 /* Post-order: see if user skipped. */
212 if (p->fts_number == SKIPPED)
213 continue;
214 break;
215 default:
216 if (!fflag &&
217 !check(p->fts_path, p->fts_accpath, p->fts_statp))
218 continue;
219 }
220
221 rval = 0;
222 /*
223 * If we can't read or search the directory, may still be
224 * able to remove it. Don't print out the un{read,search}able
225 * message unless the remove fails.
226 */
227 switch (p->fts_info) {
228 case FTS_DP:
229 case FTS_DNR:
230 rval = rmdir(p->fts_accpath);
231 if (rval != 0 && fflag && errno == ENOENT)
232 continue;
233 break;
234
235 case FTS_W:
236 rval = undelete(p->fts_accpath);
237 if (rval != 0 && fflag && errno == ENOENT)
238 continue;
239 break;
240
241 default:
242 if (Pflag)
243 rm_overwrite(p->fts_accpath, NULL);
244 rval = unlink(p->fts_accpath);
245 if (rval != 0 && fflag && NONEXISTENT(errno))
246 continue;
247 break;
248 }
249 if (rval != 0) {
250 warn("%s", p->fts_path);
251 eval = 1;
252 } else if (vflag)
253 (void)printf("%s\n", p->fts_path);
254 }
255 if (errno)
256 err(1, "fts_read");
257 }
258
259 void
260 rm_file(char **argv)
261 {
262 struct stat sb;
263 int rval;
264 char *f;
265
266 /*
267 * Remove a file. POSIX 1003.2 states that, by default, attempting
268 * to remove a directory is an error, so must always stat the file.
269 */
270 while ((f = *argv++) != NULL) {
271 /* Assume if can't stat the file, can't unlink it. */
272 if (lstat(f, &sb)) {
273 if (Wflag) {
274 sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
275 } else {
276 if (!fflag || !NONEXISTENT(errno)) {
277 warn("%s", f);
278 eval = 1;
279 }
280 continue;
281 }
282 } else if (Wflag) {
283 warnx("%s: %s", f, strerror(EEXIST));
284 eval = 1;
285 continue;
286 }
287
288 if (S_ISDIR(sb.st_mode) && !dflag) {
289 warnx("%s: is a directory", f);
290 eval = 1;
291 continue;
292 }
293 if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
294 continue;
295 if (S_ISWHT(sb.st_mode))
296 rval = undelete(f);
297 else if (S_ISDIR(sb.st_mode))
298 rval = rmdir(f);
299 else {
300 if (Pflag)
301 rm_overwrite(f, &sb);
302 rval = unlink(f);
303 }
304 if (rval && (!fflag || !NONEXISTENT(errno))) {
305 warn("%s", f);
306 eval = 1;
307 }
308 if (vflag && rval == 0)
309 (void)printf("%s\n", f);
310 }
311 }
312
313 /*
314 * rm_overwrite --
315 * Overwrite the file 3 times with varying bit patterns.
316 *
317 * XXX
318 * This is a cheap way to *really* delete files. Note that only regular
319 * files are deleted, directories (and therefore names) will remain.
320 * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
321 * System V file system). In a logging file system, you'll have to have
322 * kernel support.
323 */
324 void
325 rm_overwrite(char *file, struct stat *sbp)
326 {
327 struct stat sb;
328 off_t len;
329 int fd, wlen;
330 char buf[8 * 1024];
331
332 fd = -1;
333 if (sbp == NULL) {
334 if (lstat(file, &sb))
335 goto err;
336 sbp = &sb;
337 }
338 if (!S_ISREG(sbp->st_mode))
339 return;
340 if ((fd = open(file, O_WRONLY, 0)) == -1)
341 goto err;
342
343 #define PASS(byte) do { \
344 memset(buf, byte, sizeof(buf)); \
345 for (len = sbp->st_size; len > 0; len -= wlen) { \
346 wlen = len < sizeof(buf) ? len : sizeof(buf); \
347 if (write(fd, buf, wlen) != wlen) \
348 goto err; \
349 } \
350 } while (/* CONSTCOND */ 0)
351 PASS(0xff);
352 if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
353 goto err;
354 PASS(0x00);
355 if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
356 goto err;
357 PASS(0xff);
358 if (!fsync(fd) && !close(fd))
359 return;
360
361 err: eval = 1;
362 warn("%s", file);
363 }
364
365 int
366 check(char *path, char *name, struct stat *sp)
367 {
368 int ch, first;
369 char modep[15];
370
371 /* Check -i first. */
372 if (iflag)
373 (void)fprintf(stderr, "remove '%s'? ", path);
374 else {
375 /*
376 * If it's not a symbolic link and it's unwritable and we're
377 * talking to a terminal, ask. Symbolic links are excluded
378 * because their permissions are meaningless. Check stdin_ok
379 * first because we may not have stat'ed the file.
380 */
381 if (!stdin_ok || S_ISLNK(sp->st_mode) ||
382 !(access(name, W_OK) && (errno != ETXTBSY)))
383 return (1);
384 strmode(sp->st_mode, modep);
385 (void)fprintf(stderr, "override %s%s%s/%s for '%s'? ",
386 modep + 1, modep[9] == ' ' ? "" : " ",
387 user_from_uid(sp->st_uid, 0),
388 group_from_gid(sp->st_gid, 0), path);
389 }
390 (void)fflush(stderr);
391
392 first = ch = getchar();
393 while (ch != '\n' && ch != EOF)
394 ch = getchar();
395 return (first == 'y' || first == 'Y');
396 }
397
398 /*
399 * POSIX.2 requires that if "." or ".." are specified as the basename
400 * portion of an operand, a diagnostic message be written to standard
401 * error and nothing more be done with such operands.
402 *
403 * Since POSIX.2 defines basename as the final portion of a path after
404 * trailing slashes have been removed, we'll remove them here.
405 */
406 #define ISDOT(a) ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
407 void
408 checkdot(char **argv)
409 {
410 char *p, **save, **t;
411 int complained;
412
413 complained = 0;
414 for (t = argv; *t;) {
415 /* strip trailing slashes */
416 p = strrchr(*t, '\0');
417 while (--p > *t && *p == '/')
418 *p = '\0';
419
420 /* extract basename */
421 if ((p = strrchr(*t, '/')) != NULL)
422 ++p;
423 else
424 p = *t;
425
426 if (ISDOT(p)) {
427 if (!complained++)
428 warnx("\".\" and \"..\" may not be removed");
429 eval = 1;
430 for (save = t; (t[0] = t[1]) != NULL; ++t)
431 continue;
432 t = save;
433 } else
434 ++t;
435 }
436 }
437
438 void
439 usage(void)
440 {
441
442 (void)fprintf(stderr, "usage: %s [-f|-i] [-dPRrvW] file ...\n",
443 getprogname());
444 exit(1);
445 /* NOTREACHED */
446 }
447