xref: /dragonfly/bin/rm/rm.c (revision 71126e33)
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 1.10 2004/11/07 20:54:51 eirikn Exp $
37  */
38 
39 #include <sys/stat.h>
40 #include <sys/param.h>
41 #include <sys/mount.h>
42 
43 #include <err.h>
44 #include <errno.h>
45 #include <fcntl.h>
46 #include <fts.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <sysexits.h>
51 #include <unistd.h>
52 
53 int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
54 int rflag, Iflag;
55 uid_t uid;
56 
57 static int	check(const char *, const char *, struct stat *);
58 static int	check2(char **);
59 static void	checkdot(char **);
60 static void	rm_file(char **);
61 static int	rm_overwrite(const char *, struct stat *);
62 static void	rm_tree(char **);
63 static void	usage(void);
64 
65 /*
66  * rm --
67  *	This rm is different from historic rm's, but is expected to match
68  *	POSIX 1003.2 behavior.  The most visible difference is that -f
69  *	has two specific effects now, ignore non-existent files and force
70  * 	file removal.
71  */
72 int
73 main(int argc, char *argv[])
74 {
75 	int ch;
76 	char *p;
77 
78 	/*
79 	 * Test for the special case where the utility is called as
80 	 * "unlink", for which the functionality provided is greatly
81 	 * simplified.
82 	 */
83 	if ((p = strrchr(argv[0], '/')) == NULL)
84 		p = argv[0];
85 	else
86 		++p;
87 	if (strcmp(p, "unlink") == 0) {
88 		while (getopt(argc, argv, "") != -1)
89 			usage();
90 		argc -= optind;
91 		argv += optind;
92 		if (argc != 1)
93 			usage();
94 		rm_file(&argv[0]);
95 		exit(eval);
96 	}
97 
98 	Pflag = rflag = 0;
99 	while ((ch = getopt(argc, argv, "dfiIPRrvW")) != -1)
100 		switch(ch) {
101 		case 'd':
102 			dflag = 1;
103 			break;
104 		case 'f':
105 			fflag = 1;
106 			iflag = 0;
107 			break;
108 		case 'i':
109 			fflag = 0;
110 			iflag = 1;
111 			break;
112 		case 'I':
113 			Iflag = 1;
114 			break;
115 		case 'P':
116 			Pflag = 1;
117 			break;
118 		case 'R':
119 		case 'r':			/* Compatibility. */
120 			rflag = 1;
121 			break;
122 		case 'v':
123 			vflag = 1;
124 			break;
125 		case 'W':
126 			Wflag = 1;
127 			break;
128 		default:
129 			usage();
130 		}
131 	argc -= optind;
132 	argv += optind;
133 
134 	if (argc < 1) {
135 		if (fflag)
136 			return 0;
137 		usage();
138 	}
139 
140 	checkdot(argv);
141 	uid = geteuid();
142 
143 	if (*argv) {
144 		stdin_ok = isatty(STDIN_FILENO);
145 
146 		if (Iflag) {
147 			if (check2(argv) == 0)
148 				exit (1);
149 		}
150 		if (rflag)
151 			rm_tree(argv);
152 		else
153 			rm_file(argv);
154 	}
155 
156 	exit (eval);
157 }
158 
159 static void
160 rm_tree(char **argv)
161 {
162 	FTS *fts;
163 	FTSENT *p;
164 	int needstat;
165 	int flags;
166 	int rval;
167 
168 	/*
169 	 * Remove a file hierarchy.  If forcing removal (-f), or interactive
170 	 * (-i) or can't ask anyway (stdin_ok), don't stat the file.
171 	 */
172 	needstat = !uid || (!fflag && !iflag && stdin_ok);
173 
174 	/*
175 	 * If the -i option is specified, the user can skip on the pre-order
176 	 * visit.  The fts_number field flags skipped directories.
177 	 */
178 #define	SKIPPED	1
179 
180 	flags = FTS_PHYSICAL;
181 	if (!needstat)
182 		flags |= FTS_NOSTAT;
183 	if (Wflag)
184 		flags |= FTS_WHITEOUT;
185 	if (!(fts = fts_open(argv, flags, NULL)))
186 		err(1, NULL);
187 	while ((p = fts_read(fts)) != NULL) {
188 		switch (p->fts_info) {
189 		case FTS_DNR:
190 			if (!fflag || p->fts_errno != ENOENT) {
191 				warnx("%s: %s",
192 				    p->fts_path, strerror(p->fts_errno));
193 				eval = 1;
194 			}
195 			continue;
196 		case FTS_ERR:
197 			errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
198 		case FTS_NS:
199 		       /*
200 			* Assume that since fts_read() couldn't stat
201 			* the file, it can't be unlinked.
202 			*/
203 			if (!needstat)
204 				break;
205 			if (!fflag || p->fts_errno != ENOENT) {
206 				warnx("%s: %s",
207 				    p->fts_path, strerror(p->fts_errno));
208 				eval = 1;
209 			}
210 			continue;
211 		case FTS_D:
212 			/* Pre-order: give user chance to skip. */
213 			if (!fflag && !check(p->fts_path, p->fts_accpath,
214 			    p->fts_statp)) {
215 				fts_set(fts, p, FTS_SKIP);
216 				p->fts_number = SKIPPED;
217 			}
218 			else if (!uid &&
219 				 (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
220 				 !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
221 				 chflags(p->fts_accpath,
222 					 p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
223 				goto err;
224 			continue;
225 		case FTS_DP:
226 			/* Post-order: see if user skipped. */
227 			if (p->fts_number == SKIPPED)
228 				continue;
229 			break;
230 		default:
231 			if (!fflag &&
232 			    !check(p->fts_path, p->fts_accpath, p->fts_statp))
233 				continue;
234 		}
235 
236 		rval = 0;
237 		if (!uid &&
238 		    (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
239 		    !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
240 			rval = chflags(p->fts_accpath,
241 				       p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
242 		if (rval == 0) {
243 			/*
244 			 * If we can't read or search the directory, may still be
245 			 * able to remove it.  Don't print out the un{read,search}able
246 			 * message unless the remove fails.
247 			 */
248 			switch (p->fts_info) {
249 			case FTS_DP:
250 			case FTS_DNR:
251 				rval = rmdir(p->fts_accpath);
252 				if (rval == 0 || (fflag && errno == ENOENT)) {
253 					if (rval == 0 && vflag)
254 						printf("%s\n",
255 						    p->fts_path);
256 					continue;
257 				}
258 				break;
259 
260 			case FTS_W:
261 				rval = undelete(p->fts_accpath);
262 				if (rval == 0 && (fflag && errno == ENOENT)) {
263 					if (vflag)
264 						printf("%s\n",
265 						    p->fts_path);
266 					continue;
267 				}
268 				break;
269 
270 			case FTS_NS:
271 			/*
272 			 * Assume that since fts_read() couldn't stat
273 			 * the file, it can't be unlinked.
274 			 */
275 				if (fflag)
276 					continue;
277 				/* FALLTHROUGH */
278 			default:
279 				if (Pflag)
280 					if (!rm_overwrite(p->fts_accpath, NULL))
281 						continue;
282 				rval = unlink(p->fts_accpath);
283 				if (rval == 0 || (fflag && errno == ENOENT)) {
284 					if (rval == 0 && vflag)
285 						printf("%s\n",
286 						    p->fts_path);
287 					continue;
288 				}
289 			}
290 		}
291 err:
292 		warn("%s", p->fts_path);
293 		eval = 1;
294 	}
295 	if (errno)
296 		err(1, "fts_read");
297 }
298 
299 static void
300 rm_file(char **argv)
301 {
302 	struct stat sb;
303 	int rval;
304 	char *f;
305 
306 	/*
307 	 * Remove a file.  POSIX 1003.2 states that, by default, attempting
308 	 * to remove a directory is an error, so must always stat the file.
309 	 */
310 	while ((f = *argv++) != NULL) {
311 		/* Assume if can't stat the file, can't unlink it. */
312 		if (lstat(f, &sb)) {
313 			if (Wflag) {
314 				sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
315 			} else {
316 				if (!fflag || errno != ENOENT) {
317 					warn("%s", f);
318 					eval = 1;
319 				}
320 				continue;
321 			}
322 		} else if (Wflag) {
323 			warnx("%s: %s", f, strerror(EEXIST));
324 			eval = 1;
325 			continue;
326 		}
327 
328 		if (S_ISDIR(sb.st_mode) && !dflag) {
329 			warnx("%s: is a directory", f);
330 			eval = 1;
331 			continue;
332 		}
333 		if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
334 			continue;
335 		rval = 0;
336 		if (!uid &&
337 		    (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
338 		    !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
339 			rval = chflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
340 		if (rval == 0) {
341 			if (S_ISWHT(sb.st_mode))
342 				rval = undelete(f);
343 			else if (S_ISDIR(sb.st_mode))
344 				rval = rmdir(f);
345 			else {
346 				if (Pflag)
347 					if (!rm_overwrite(f, &sb))
348 						continue;
349 				rval = unlink(f);
350 			}
351 		}
352 		if (rval && (!fflag || errno != ENOENT)) {
353 			warn("%s", f);
354 			eval = 1;
355 		}
356 		if (vflag && rval == 0)
357 			printf("%s\n", f);
358 	}
359 }
360 
361 /*
362  * rm_overwrite --
363  *	Overwrite the file 3 times with varying bit patterns.
364  *
365  * XXX
366  * This is a cheap way to *really* delete files.  Note that only regular
367  * files are deleted, directories (and therefore names) will remain.
368  * Also, this assumes a fixed-block filesystem (like FFS, or a V7 or a
369  * System V filesystem).  In a logging filesystem, you'll have to have
370  * kernel support.
371  */
372 static int
373 rm_overwrite(const char *file, struct stat *sbp)
374 {
375 	struct stat sb;
376 	struct statfs fsb;
377 	off_t len;
378 	int bsize, fd, wlen;
379 	char *buf = NULL;
380 
381 	fd = -1;
382 	if (sbp == NULL) {
383 		if (lstat(file, &sb))
384 			goto err;
385 		sbp = &sb;
386 	}
387 	if (!S_ISREG(sbp->st_mode)) {
388 		warnx("%s: cannot overwrite a non-regular file", file);
389 		return (1);
390 	}
391 	if ((fd = open(file, O_WRONLY, 0)) == -1)
392 		goto err;
393 	if (fstatfs(fd, &fsb) == -1)
394 		goto err;
395 	bsize = MAX(fsb.f_iosize, 1024);
396 	if ((buf = malloc(bsize)) == NULL)
397 		err(1, "%s malloc failed", file);
398 
399 #define	PASS(byte) {							\
400 	memset(buf, byte, bsize);					\
401 	for (len = sbp->st_size; len > 0; len -= wlen) {		\
402 		wlen = len < bsize ? len : bsize;			\
403 		if (write(fd, buf, wlen) != wlen)			\
404 			goto err;					\
405 	}								\
406 }
407 	PASS(0xff);
408 	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
409 		goto err;
410 	PASS(0x00);
411 	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
412 		goto err;
413 	PASS(0xff);
414 	if (!fsync(fd) && !close(fd)) {
415 		free(buf);
416 		return (1);
417 	}
418 
419 err:	eval = 1;
420 	if (buf)
421 		free(buf);
422 	if (fd != -1)
423 		close(fd);
424 	warn("%s", file);
425 	return (0);
426 }
427 
428 
429 static int
430 check(const char *path, const char *name, struct stat *sp)
431 {
432 	int ch, first;
433 	char modep[15], *flagsp;
434 
435 	/* Check -i first. */
436 	if (iflag)
437 		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 		 * Also skip this check if the -P option was specified because
445   	         * we will not be able to overwrite file contents and will
446   	         * barf later.
447 		 */
448 		if (!stdin_ok || S_ISLNK(sp->st_mode) || Pflag ||
449 		    (!access(name, W_OK) &&
450 		    !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
451 		    (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
452 			return (1);
453 		strmode(sp->st_mode, modep);
454 		if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
455 			err(1, NULL);
456 		fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
457 		    modep + 1, modep[9] == ' ' ? "" : " ",
458 		    user_from_uid(sp->st_uid, 0),
459 		    group_from_gid(sp->st_gid, 0),
460 		    *flagsp ? flagsp : "", *flagsp ? " " : "",
461 		    path);
462 		free(flagsp);
463 	}
464 	fflush(stderr);
465 
466 	first = ch = getchar();
467 	while (ch != '\n' && ch != EOF)
468 		ch = getchar();
469 	return (first == 'y' || first == 'Y');
470 }
471 
472 static int
473 check2(char **argv)
474 {
475 	struct stat st;
476 	int first;
477 	int ch;
478 	int fcount = 0;
479 	int dcount = 0;
480 	int i;
481 	const char *dname = NULL;
482 
483 	for (i = 0; argv[i]; ++i) {
484 		if (lstat(argv[i], &st) == 0) {
485 			if (S_ISDIR(st.st_mode)) {
486 				++dcount;
487 				dname = argv[i];    /* only used if 1 dir */
488 			} else {
489 				++fcount;
490 			}
491 		}
492 	}
493 	first = 0;
494 	while (first != 'n' && first != 'N' && first != 'y' && first != 'Y') {
495 		if (dcount && rflag) {
496 			fprintf(stderr, "recursively remove");
497 			if (dcount == 1)
498 				fprintf(stderr, " %s", dname);
499 			else
500 				fprintf(stderr, " %d dirs", dcount);
501 			if (fcount == 1)
502 				fprintf(stderr, " and 1 file");
503 			else if (fcount > 1)
504 				fprintf(stderr, " and %d files", fcount);
505 		} else if (dcount + fcount > 3) {
506 			fprintf(stderr, "remove %d files", dcount + fcount);
507 		} else {
508 			return(1);
509 		}
510 		fprintf(stderr, "? ");
511 		fflush(stderr);
512 
513 		first = ch = getchar();
514 		while (ch != '\n' && ch != EOF)
515 			ch = getchar();
516 		if (ch == EOF)
517 			break;
518 	}
519 	return (first == 'y' || first == 'Y');
520 }
521 
522 #define ISDOT(a)	((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
523 static void
524 checkdot(char **argv)
525 {
526 	char *p, **save, **t;
527 	int complained;
528 
529 	complained = 0;
530 	for (t = argv; *t;) {
531 		if ((p = strrchr(*t, '/')) != NULL)
532 			++p;
533 		else
534 			p = *t;
535 		if (ISDOT(p)) {
536 			if (!complained++)
537 				warnx("\".\" and \"..\" may not be removed");
538 			eval = 1;
539 			for (save = t; (t[0] = t[1]) != NULL; ++t)
540 				continue;
541 			t = save;
542 		} else
543 			++t;
544 	}
545 }
546 
547 static void
548 usage(void)
549 {
550 
551 	fprintf(stderr, "%s\n%s\n",
552 	    "usage: rm [-f | -i] [-dIPRrvW] file ...",
553 	    "       unlink file");
554 	exit(EX_USAGE);
555 }
556