xref: /openbsd-src/bin/rm/rm.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: rm.c,v 1.10 2001/06/08 13:40:20 millert Exp $	*/
2 /*	$NetBSD: rm.c,v 1.19 1995/09/07 06:48:50 jtc Exp $	*/
3 
4 /*-
5  * Copyright (c) 1990, 1993, 1994
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #ifndef lint
38 static char copyright[] =
39 "@(#) Copyright (c) 1990, 1993, 1994\n\
40 	The Regents of the University of California.  All rights reserved.\n";
41 #endif /* not lint */
42 
43 #ifndef lint
44 #if 0
45 static char sccsid[] = "@(#)rm.c	8.8 (Berkeley) 4/27/95";
46 #else
47 static char rcsid[] = "$OpenBSD: rm.c,v 1.10 2001/06/08 13:40:20 millert Exp $";
48 #endif
49 #endif /* not lint */
50 
51 #include <sys/types.h>
52 #include <sys/stat.h>
53 #include <sys/param.h>
54 #include <sys/mount.h>
55 
56 #include <locale.h>
57 #include <err.h>
58 #include <errno.h>
59 #include <fcntl.h>
60 #include <fts.h>
61 #include <stdio.h>
62 #include <stdlib.h>
63 #include <string.h>
64 #include <unistd.h>
65 #include <pwd.h>
66 #include <grp.h>
67 
68 int dflag, eval, fflag, iflag, Pflag, Wflag, stdin_ok;
69 
70 int	check __P((char *, char *, struct stat *));
71 void	checkdot __P((char **));
72 void	rm_file __P((char **));
73 void	rm_overwrite __P((char *, struct stat *));
74 void	rm_tree __P((char **));
75 void	usage __P((void));
76 
77 /*
78  * rm --
79  *	This rm is different from historic rm's, but is expected to match
80  *	POSIX 1003.2 behavior.  The most visible difference is that -f
81  *	has two specific effects now, ignore non-existent files and force
82  * 	file removal.
83  */
84 int
85 main(argc, argv)
86 	int argc;
87 	char *argv[];
88 {
89 	int ch, rflag;
90 
91 	setlocale(LC_ALL, "");
92 
93 	Pflag = rflag = 0;
94 	while ((ch = getopt(argc, argv, "dfiPRrW")) != -1)
95 		switch(ch) {
96 		case 'd':
97 			dflag = 1;
98 			break;
99 		case 'f':
100 			fflag = 1;
101 			iflag = 0;
102 			break;
103 		case 'i':
104 			fflag = 0;
105 			iflag = 1;
106 			break;
107 		case 'P':
108 			Pflag = 1;
109 			break;
110 		case 'R':
111 		case 'r':			/* Compatibility. */
112 			rflag = 1;
113 			break;
114 		case 'W':
115 			Wflag = 1;
116 			break;
117 		default:
118 			usage();
119 		}
120 	argc -= optind;
121 	argv += optind;
122 
123 	if (argc < 1 && fflag == 0)
124 		usage();
125 
126 	checkdot(argv);
127 
128 	if (*argv) {
129 		stdin_ok = isatty(STDIN_FILENO);
130 
131 		if (rflag)
132 			rm_tree(argv);
133 		else
134 			rm_file(argv);
135 	}
136 
137 	exit (eval);
138 }
139 
140 void
141 rm_tree(argv)
142 	char **argv;
143 {
144 	FTS *fts;
145 	FTSENT *p;
146 	int needstat;
147 	int flags;
148 
149 	/*
150 	 * Remove a file hierarchy.  If forcing removal (-f), or interactive
151 	 * (-i) or can't ask anyway (stdin_ok), don't stat the file.
152 	 */
153 	needstat = !fflag && !iflag && stdin_ok;
154 
155 	/*
156 	 * If the -i option is specified, the user can skip on the pre-order
157 	 * visit.  The fts_number field flags skipped directories.
158 	 */
159 #define	SKIPPED	1
160 
161 	flags = FTS_PHYSICAL;
162 	if (!needstat)
163 		flags |= FTS_NOSTAT;
164 	if (Wflag)
165 		flags |= FTS_WHITEOUT;
166 	if (!(fts = fts_open(argv, flags, NULL)))
167 		err(1, NULL);
168 	while ((p = fts_read(fts)) != NULL) {
169 		switch (p->fts_info) {
170 		case FTS_DNR:
171 			if (!fflag || p->fts_errno != ENOENT) {
172 				warnx("%s: %s",
173 				    p->fts_path, strerror(p->fts_errno));
174 				eval = 1;
175 			}
176 			continue;
177 		case FTS_ERR:
178 			errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
179 		case FTS_NS:
180 			/*
181 			 * FTS_NS: assume that if can't stat the file, it
182 			 * can't be unlinked.
183 			 */
184 			if (!needstat)
185 				break;
186 			if (!fflag || p->fts_errno != ENOENT) {
187 				warnx("%s: %s",
188 				    p->fts_path, strerror(p->fts_errno));
189 				eval = 1;
190 			}
191 			continue;
192 		case FTS_D:
193 			/* Pre-order: give user chance to skip. */
194 			if (!fflag && !check(p->fts_path, p->fts_accpath,
195 			    p->fts_statp)) {
196 				(void)fts_set(fts, p, FTS_SKIP);
197 				p->fts_number = SKIPPED;
198 			}
199 			continue;
200 		case FTS_DP:
201 			/* Post-order: see if user skipped. */
202 			if (p->fts_number == SKIPPED)
203 				continue;
204 			break;
205 		default:
206 			if (!fflag &&
207 			    !check(p->fts_path, p->fts_accpath, p->fts_statp))
208 				continue;
209 		}
210 
211 		/*
212 		 * If we can't read or search the directory, may still be
213 		 * able to remove it.  Don't print out the un{read,search}able
214 		 * message unless the remove fails.
215 		 */
216 		switch (p->fts_info) {
217 		case FTS_DP:
218 		case FTS_DNR:
219 			if (!rmdir(p->fts_accpath) ||
220 			    (fflag && errno == ENOENT))
221 				continue;
222 			break;
223 
224 		case FTS_W:
225 			if (!undelete(p->fts_accpath) ||
226 			    (fflag && errno == ENOENT))
227 				continue;
228 			break;
229 
230 		default:
231 			if (Pflag)
232 				rm_overwrite(p->fts_accpath, NULL);
233 			if (!unlink(p->fts_accpath) ||
234 			    (fflag && errno == ENOENT))
235 				continue;
236 		}
237 		warn("%s", p->fts_path);
238 		eval = 1;
239 	}
240 	if (errno)
241 		err(1, "fts_read");
242 }
243 
244 void
245 rm_file(argv)
246 	char **argv;
247 {
248 	struct stat sb;
249 	int rval;
250 	char *f;
251 
252 	/*
253 	 * Remove a file.  POSIX 1003.2 states that, by default, attempting
254 	 * to remove a directory is an error, so must always stat the file.
255 	 */
256 	while ((f = *argv++) != NULL) {
257 		/* Assume if can't stat the file, can't unlink it. */
258 		if (lstat(f, &sb)) {
259 			if (Wflag) {
260 				sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
261 			} else {
262 				if (!fflag || errno != ENOENT) {
263 					warn("%s", f);
264 					eval = 1;
265 				}
266 				continue;
267 			}
268 		} else if (Wflag) {
269 			warnx("%s: %s", f, strerror(EEXIST));
270 			eval = 1;
271 			continue;
272 		}
273 
274 		if (S_ISDIR(sb.st_mode) && !dflag) {
275 			warnx("%s: is a directory", f);
276 			eval = 1;
277 			continue;
278 		}
279 		if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
280 			continue;
281 		if (S_ISWHT(sb.st_mode))
282 			rval = undelete(f);
283 		else if (S_ISDIR(sb.st_mode))
284 			rval = rmdir(f);
285 		else {
286 			if (Pflag)
287 				rm_overwrite(f, &sb);
288 			rval = unlink(f);
289 		}
290 		if (rval && (!fflag || errno != ENOENT)) {
291 			warn("%s", f);
292 			eval = 1;
293 		}
294 	}
295 }
296 
297 /*
298  * rm_overwrite --
299  *	Overwrite the file 3 times with varying bit patterns.
300  *
301  * XXX
302  * This is a cheap way to *really* delete files.  Note that only regular
303  * files are deleted, directories (and therefore names) will remain.
304  * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
305  * System V file system).  In a logging file system, you'll have to have
306  * kernel support.
307  */
308 void
309 rm_overwrite(file, sbp)
310 	char *file;
311 	struct stat *sbp;
312 {
313 	struct stat sb;
314 	struct statfs fsb;
315 	off_t len;
316 	int bsize, fd, wlen;
317 	char *buf = NULL;
318 
319 	fd = -1;
320 	if (sbp == NULL) {
321 		if (lstat(file, &sb))
322 			goto err;
323 		sbp = &sb;
324 	}
325 	if (!S_ISREG(sbp->st_mode))
326 		return;
327 	if ((fd = open(file, O_WRONLY, 0)) == -1)
328 		goto err;
329 	if (fstatfs(fd, &fsb) == -1)
330 		goto err;
331 	bsize = MAX(fsb.f_iosize, 1024);
332 	if ((buf = malloc(bsize)) == NULL)
333 		err(1, "malloc");
334 
335 #define	PASS(byte) {							\
336 	memset(buf, byte, bsize);					\
337 	for (len = sbp->st_size; len > 0; len -= wlen) {		\
338 		wlen = len < bsize ? len : bsize;			\
339 		if (write(fd, buf, wlen) != wlen)			\
340 			goto err;					\
341 	}								\
342 }
343 	PASS(0xff);
344 	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
345 		goto err;
346 	PASS(0x00);
347 	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
348 		goto err;
349 	PASS(0xff);
350 	if (!fsync(fd) && !close(fd)) {
351 		free(buf);
352 		return;
353 	}
354 
355 err:	eval = 1;
356 	if (buf)
357 		free(buf);
358 	warn("%s", file);
359 }
360 
361 
362 int
363 check(path, name, sp)
364 	char *path, *name;
365 	struct stat *sp;
366 {
367 	int ch, first;
368 	char modep[15];
369 
370 	/* Check -i first. */
371 	if (iflag)
372 		(void)fprintf(stderr, "remove %s? ", path);
373 	else {
374 		/*
375 		 * If it's not a symbolic link and it's unwritable and we're
376 		 * talking to a terminal, ask.  Symbolic links are excluded
377 		 * because their permissions are meaningless.  Check stdin_ok
378 		 * first because we may not have stat'ed the file.
379 		 */
380 		if (!stdin_ok || S_ISLNK(sp->st_mode) || !access(name, W_OK))
381 			return (1);
382 		strmode(sp->st_mode, modep);
383 		(void)fprintf(stderr, "override %s%s%s/%s for %s? ",
384 		    modep + 1, modep[9] == ' ' ? "" : " ",
385 		    user_from_uid(sp->st_uid, 0),
386 		    group_from_gid(sp->st_gid, 0), path);
387 	}
388 	(void)fflush(stderr);
389 
390 	first = ch = getchar();
391 	while (ch != '\n' && ch != EOF)
392 		ch = getchar();
393 	return (first == 'y' || first == 'Y');
394 }
395 
396 /*
397  * POSIX.2 requires that if "." or ".." are specified as the basename
398  * portion of an operand, a diagnostic message be written to standard
399  * error and nothing more be done with such operands.
400  *
401  * Since POSIX.2 defines basename as the final portion of a path after
402  * trailing slashes have been removed, we'll remove them here.
403  */
404 #define ISDOT(a)	((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
405 void
406 checkdot(argv)
407 	char **argv;
408 {
409 	char *p, **save, **t;
410 	int complained;
411 
412 	complained = 0;
413 	for (t = argv; *t;) {
414 		/* strip trailing slashes */
415 		p = strrchr (*t, '\0');
416 		while (--p > *t && *p == '/')
417 			*p = '\0';
418 
419 		/* extract basename */
420 		if ((p = strrchr(*t, '/')) != NULL)
421 			++p;
422 		else
423 			p = *t;
424 
425 		if (ISDOT(p)) {
426 			if (!complained++)
427 				warnx("\".\" and \"..\" may not be removed");
428 			eval = 1;
429 			for (save = t; (t[0] = t[1]) != NULL; ++t)
430 				continue;
431 			t = save;
432 		} else
433 			++t;
434 	}
435 }
436 
437 void
438 usage()
439 {
440 
441 	(void)fprintf(stderr, "usage: rm [-dfiPRrW] file ...\n");
442 	exit(1);
443 }
444