rm.c revision 56692 
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
35static 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
42static char sccsid[] = "@(#)rm.c	8.5 (Berkeley) 4/18/94";
43#else
44static const char rcsid[] =
45  "$FreeBSD: head/bin/rm/rm.c 56692 2000-01-27 21:17:01Z joe $";
46#endif
47#endif /* not lint */
48
49#include <sys/types.h>
50#include <sys/stat.h>
51#include <sys/param.h>
52#include <sys/mount.h>
53
54#include <err.h>
55#include <errno.h>
56#include <fcntl.h>
57#include <fts.h>
58#include <stdio.h>
59#include <stdlib.h>
60#include <string.h>
61#include <sysexits.h>
62#include <unistd.h>
63
64int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
65uid_t uid;
66
67int	check __P((char *, char *, struct stat *));
68void	checkdot __P((char **));
69void	rm_file __P((char **));
70void	rm_overwrite __P((char *, struct stat *));
71void	rm_tree __P((char **));
72void	usage __P((void));
73
74/*
75 * rm --
76 *	This rm is different from historic rm's, but is expected to match
77 *	POSIX 1003.2 behavior.  The most visible difference is that -f
78 *	has two specific effects now, ignore non-existent files and force
79 * 	file removal.
80 */
81int
82main(argc, argv)
83	int argc;
84	char *argv[];
85{
86	int ch, rflag;
87	char *p;
88
89	/*
90	 * Test for the special case where the utility is called as
91	 * "unlink", for which the functionality provided is greatly
92	 * simplified.
93	 */
94	if ((p = rindex(argv[0], '/')) == NULL)
95		p = argv[0];
96	else
97		++p;
98	if (strcmp(p, "unlink") == 0) {
99		if (argc == 2) {
100			rm_file(&argv[1]);
101			exit(eval);
102		} else
103			usage();
104	}
105
106	Pflag = rflag = 0;
107	while ((ch = getopt(argc, argv, "dfiPRrvW")) != -1)
108		switch(ch) {
109		case 'd':
110			dflag = 1;
111			break;
112		case 'f':
113			fflag = 1;
114			iflag = 0;
115			break;
116		case 'i':
117			fflag = 0;
118			iflag = 1;
119			break;
120		case 'P':
121			Pflag = 1;
122			break;
123		case 'R':
124		case 'r':			/* Compatibility. */
125			rflag = 1;
126			break;
127		case 'v':
128			vflag = 1;
129			break;
130		case 'W':
131			Wflag = 1;
132			break;
133		default:
134			usage();
135		}
136	argc -= optind;
137	argv += optind;
138
139	if (argc < 1) {
140		if (fflag)
141			return 0;
142		usage();
143	}
144
145	checkdot(argv);
146	uid = geteuid();
147
148	if (*argv) {
149		stdin_ok = isatty(STDIN_FILENO);
150
151		if (rflag)
152			rm_tree(argv);
153		else
154			rm_file(argv);
155	}
156
157	exit (eval);
158}
159
160void
161rm_tree(argv)
162	char **argv;
163{
164	FTS *fts;
165	FTSENT *p;
166	int needstat;
167	int flags;
168	int rval;
169
170	/*
171	 * Remove a file hierarchy.  If forcing removal (-f), or interactive
172	 * (-i) or can't ask anyway (stdin_ok), don't stat the file.
173	 */
174	needstat = !uid || (!fflag && !iflag && stdin_ok);
175
176	/*
177	 * If the -i option is specified, the user can skip on the pre-order
178	 * visit.  The fts_number field flags skipped directories.
179	 */
180#define	SKIPPED	1
181
182	flags = FTS_PHYSICAL;
183	if (!needstat)
184		flags |= FTS_NOSTAT;
185	if (Wflag)
186		flags |= FTS_WHITEOUT;
187	if (!(fts = fts_open(argv, flags, (int (*)())NULL)))
188		err(1, NULL);
189	while ((p = fts_read(fts)) != NULL) {
190		switch (p->fts_info) {
191		case FTS_DNR:
192			if (!fflag || p->fts_errno != ENOENT) {
193				warnx("%s: %s",
194				    p->fts_path, strerror(p->fts_errno));
195				eval = 1;
196			}
197			continue;
198		case FTS_ERR:
199			errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
200		case FTS_NS:
201			/*
202			 * FTS_NS: assume that if can't stat the file, it
203			 * can't be unlinked.
204			 */
205			if (!needstat)
206				break;
207			if (!fflag || p->fts_errno != ENOENT) {
208				warnx("%s: %s",
209				    p->fts_path, strerror(p->fts_errno));
210				eval = 1;
211			}
212			continue;
213		case FTS_D:
214			/* Pre-order: give user chance to skip. */
215			if (!fflag && !check(p->fts_path, p->fts_accpath,
216			    p->fts_statp)) {
217				(void)fts_set(fts, p, FTS_SKIP);
218				p->fts_number = SKIPPED;
219			}
220			else if (!uid &&
221				 (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
222				 !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
223				 chflags(p->fts_accpath,
224					 p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
225				goto err;
226			continue;
227		case FTS_DP:
228			/* Post-order: see if user skipped. */
229			if (p->fts_number == SKIPPED)
230				continue;
231			break;
232		default:
233			if (!fflag &&
234			    !check(p->fts_path, p->fts_accpath, p->fts_statp))
235				continue;
236		}
237
238		rval = 0;
239		if (!uid &&
240		    (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
241		    !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
242			rval = chflags(p->fts_accpath,
243				       p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
244		if (rval == 0) {
245			/*
246			 * If we can't read or search the directory, may still be
247			 * able to remove it.  Don't print out the un{read,search}able
248			 * message unless the remove fails.
249			 */
250			switch (p->fts_info) {
251			case FTS_DP:
252			case FTS_DNR:
253				rval = rmdir(p->fts_accpath);
254				if (rval == 0 || (fflag && errno == ENOENT)) {
255					if (rval == 0 && vflag)
256						(void)printf("%s\n",
257						    p->fts_accpath);
258					continue;
259				}
260				break;
261
262			case FTS_W:
263				rval = undelete(p->fts_accpath);
264				if (rval == 0 && (fflag && errno == ENOENT)) {
265					if (vflag)
266						(void)printf("%s\n",
267						    p->fts_accpath);
268					continue;
269				}
270				break;
271
272			default:
273				if (Pflag)
274					rm_overwrite(p->fts_accpath, NULL);
275				rval = unlink(p->fts_accpath);
276				if (rval == 0 || (fflag && errno == ENOENT)) {
277					if (rval == 0 && vflag)
278						(void)printf("%s\n",
279						    p->fts_accpath);
280					continue;
281				}
282			}
283		}
284err:
285		warn("%s", p->fts_path);
286		eval = 1;
287	}
288	if (errno)
289		err(1, "fts_read");
290}
291
292void
293rm_file(argv)
294	char **argv;
295{
296	struct stat sb;
297	int rval;
298	char *f;
299
300	/*
301	 * Remove a file.  POSIX 1003.2 states that, by default, attempting
302	 * to remove a directory is an error, so must always stat the file.
303	 */
304	while ((f = *argv++) != NULL) {
305		/* Assume if can't stat the file, can't unlink it. */
306		if (lstat(f, &sb)) {
307			if (Wflag) {
308				sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
309			} else {
310				if (!fflag || errno != ENOENT) {
311					warn("%s", f);
312					eval = 1;
313				}
314				continue;
315			}
316		} else if (Wflag) {
317			warnx("%s: %s", f, strerror(EEXIST));
318			eval = 1;
319			continue;
320		}
321
322		if (S_ISDIR(sb.st_mode) && !dflag) {
323			warnx("%s: is a directory", f);
324			eval = 1;
325			continue;
326		}
327		if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
328			continue;
329		rval = 0;
330		if (!uid &&
331		    (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
332		    !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
333			rval = chflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
334		if (rval == 0) {
335			if (S_ISWHT(sb.st_mode))
336				rval = undelete(f);
337			else if (S_ISDIR(sb.st_mode))
338				rval = rmdir(f);
339			else {
340				if (Pflag)
341					rm_overwrite(f, &sb);
342				rval = unlink(f);
343			}
344		}
345		if (rval && (!fflag || errno != ENOENT)) {
346			warn("%s", f);
347			eval = 1;
348		}
349		if (vflag && rval == 0)
350			(void)printf("%s\n", f);
351	}
352}
353
354/*
355 * rm_overwrite --
356 *	Overwrite the file 3 times with varying bit patterns.
357 *
358 * XXX
359 * This is a cheap way to *really* delete files.  Note that only regular
360 * files are deleted, directories (and therefore names) will remain.
361 * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
362 * System V file system).  In a logging file system, you'll have to have
363 * kernel support.
364 */
365void
366rm_overwrite(file, sbp)
367	char *file;
368	struct stat *sbp;
369{
370	struct stat sb;
371	struct statfs fsb;
372	off_t len;
373	int bsize, fd, wlen;
374	char *buf = NULL;
375
376	fd = -1;
377	if (sbp == NULL) {
378		if (lstat(file, &sb))
379			goto err;
380		sbp = &sb;
381	}
382	if (!S_ISREG(sbp->st_mode))
383		return;
384	if ((fd = open(file, O_WRONLY, 0)) == -1)
385		goto err;
386	if (fstatfs(fd, &fsb) == -1)
387		goto err;
388	bsize = MAX(fsb.f_iosize, 1024);
389	if ((buf = malloc(bsize)) == NULL)
390		err(1, "malloc");
391
392#define	PASS(byte) {							\
393	memset(buf, byte, bsize);					\
394	for (len = sbp->st_size; len > 0; len -= wlen) {		\
395		wlen = len < bsize ? len : bsize;			\
396		if (write(fd, buf, wlen) != wlen)			\
397			goto err;					\
398	}								\
399}
400	PASS(0xff);
401	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
402		goto err;
403	PASS(0x00);
404	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
405		goto err;
406	PASS(0xff);
407	if (!fsync(fd) && !close(fd)) {
408		free(buf);
409		return;
410	}
411
412err:	eval = 1;
413	if (buf)
414		free(buf);
415	warn("%s", file);
416}
417
418
419int
420check(path, name, sp)
421	char *path, *name;
422	struct stat *sp;
423{
424	int ch, first;
425	char modep[15], flagsp[128];
426
427	/* Check -i first. */
428	if (iflag)
429		(void)fprintf(stderr, "remove %s? ", path);
430	else {
431		/*
432		 * If it's not a symbolic link and it's unwritable and we're
433		 * talking to a terminal, ask.  Symbolic links are excluded
434		 * because their permissions are meaningless.  Check stdin_ok
435		 * first because we may not have stat'ed the file.
436		 */
437		if (!stdin_ok || S_ISLNK(sp->st_mode) ||
438		    (!access(name, W_OK) &&
439		    !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
440		    (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
441			return (1);
442		strmode(sp->st_mode, modep);
443		strcpy(flagsp, getflags(sp->st_flags, NULL));
444		if (*flagsp)
445			strcat(flagsp, " ");
446		(void)fprintf(stderr, "override %s%s%s/%s %sfor %s? ",
447		    modep + 1, modep[9] == ' ' ? "" : " ",
448		    user_from_uid(sp->st_uid, 0),
449		    group_from_gid(sp->st_gid, 0),
450		    *flagsp ? flagsp : "",
451		    path);
452	}
453	(void)fflush(stderr);
454
455	first = ch = getchar();
456	while (ch != '\n' && ch != EOF)
457		ch = getchar();
458	return (first == 'y' || first == 'Y');
459}
460
461#define ISDOT(a)	((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
462void
463checkdot(argv)
464	char **argv;
465{
466	char *p, **save, **t;
467	int complained;
468
469	complained = 0;
470	for (t = argv; *t;) {
471		if ((p = strrchr(*t, '/')) != NULL)
472			++p;
473		else
474			p = *t;
475		if (ISDOT(p)) {
476			if (!complained++)
477				warnx("\".\" and \"..\" may not be removed");
478			eval = 1;
479			for (save = t; (t[0] = t[1]) != NULL; ++t)
480				continue;
481			t = save;
482		} else
483			++t;
484	}
485}
486
487void
488usage()
489{
490
491	(void)fprintf(stderr, "%s\n%s\n",
492	    "usage: rm [-f | -i] [-dPRrvW] file ...",
493	    "       unlink file");
494	exit(EX_USAGE);
495}
496