rm.c revision 20421 
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 *	$Id: rm.c,v 1.11 1996/03/07 23:26:59 wosch Exp $
34 */
35
36#ifndef lint
37static char const copyright[] =
38"@(#) Copyright (c) 1990, 1993, 1994\n\
39	The Regents of the University of California.  All rights reserved.\n";
40#endif /* not lint */
41
42#ifndef lint
43static char const sccsid[] = "@(#)rm.c	8.5 (Berkeley) 4/18/94";
44#endif /* not lint */
45
46#include <sys/types.h>
47#include <sys/stat.h>
48
49#include <err.h>
50#include <errno.h>
51#include <fcntl.h>
52#include <fts.h>
53#include <stdio.h>
54#include <stdlib.h>
55#include <string.h>
56#include <unistd.h>
57
58/*
59 * XXX Until we get kernel support for the undelete(2) system call,
60 * this define *must* remain in place.
61 */
62#define BSD4_4_LITE
63
64extern char *flags_to_string __P((u_long, char *));
65
66#ifdef BSD4_4_LITE
67int dflag, eval, fflag, iflag, Pflag, stdin_ok;
68#else
69int dflag, eval, fflag, iflag, Pflag, Wflag, stdin_ok;
70#endif
71uid_t uid;
72
73int	check __P((char *, char *, struct stat *));
74void	checkdot __P((char **));
75void	rm_file __P((char **));
76void	rm_overwrite __P((char *, struct stat *));
77void	rm_tree __P((char **));
78void	usage __P((void));
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 */
87int
88main(argc, argv)
89	int argc;
90	char *argv[];
91{
92	int ch, rflag;
93
94	Pflag = rflag = 0;
95#ifdef BSD4_4_LITE
96	while ((ch = getopt(argc, argv, "dfiPRr")) != EOF)
97#else
98	while ((ch = getopt(argc, argv, "dfiPRrW")) != EOF)
99#endif
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 'P':
113			Pflag = 1;
114			break;
115		case 'R':
116		case 'r':			/* Compatibility. */
117			rflag = 1;
118			break;
119#ifndef BSD4_4_LITE
120		case 'W':
121			Wflag = 1;
122			break;
123#endif
124		default:
125			usage();
126		}
127	argc -= optind;
128	argv += optind;
129
130	if (argc < 1)
131		usage();
132
133	checkdot(argv);
134	uid = geteuid();
135
136	if (*argv) {
137		stdin_ok = isatty(STDIN_FILENO);
138
139		if (rflag)
140			rm_tree(argv);
141		else
142			rm_file(argv);
143	}
144
145	exit (eval);
146}
147
148void
149rm_tree(argv)
150	char **argv;
151{
152	FTS *fts;
153	FTSENT *p;
154	int needstat;
155	int flags;
156	int rval;
157
158	/*
159	 * Remove a file hierarchy.  If forcing removal (-f), or interactive
160	 * (-i) or can't ask anyway (stdin_ok), don't stat the file.
161	 */
162	needstat = !uid || (!fflag && !iflag && stdin_ok);
163
164	/*
165	 * If the -i option is specified, the user can skip on the pre-order
166	 * visit.  The fts_number field flags skipped directories.
167	 */
168#define	SKIPPED	1
169
170	flags = FTS_PHYSICAL | FTS_NOCHDIR;
171	if (!needstat)
172		flags |= FTS_NOSTAT;
173#ifndef BSD4_4_LITE
174	if (Wflag)
175		flags |= FTS_WHITEOUT;
176#endif
177	if (!(fts = fts_open(argv, flags, (int (*)())NULL)))
178		err(1, NULL);
179	while ((p = fts_read(fts)) != NULL) {
180		switch (p->fts_info) {
181		case FTS_DNR:
182			if (!fflag || p->fts_errno != ENOENT) {
183				warnx("%s: %s",
184				    p->fts_path, strerror(p->fts_errno));
185				eval = 1;
186			}
187			continue;
188		case FTS_ERR:
189			errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
190		case FTS_NS:
191			/*
192			 * FTS_NS: assume that if can't stat the file, it
193			 * can't be unlinked.
194			 */
195			if (!needstat)
196				break;
197			if (!fflag || p->fts_errno != ENOENT) {
198				warnx("%s: %s",
199				    p->fts_path, strerror(p->fts_errno));
200				eval = 1;
201			}
202			continue;
203		case FTS_D:
204			/* Pre-order: give user chance to skip. */
205			if (!fflag && !check(p->fts_path, p->fts_accpath,
206			    p->fts_statp)) {
207				(void)fts_set(fts, p, FTS_SKIP);
208				p->fts_number = SKIPPED;
209			}
210			else if (!uid &&
211				 (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
212				 !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
213				 chflags(p->fts_accpath,
214					 p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
215				goto err;
216			continue;
217		case FTS_DP:
218			/* Post-order: see if user skipped. */
219			if (p->fts_number == SKIPPED)
220				continue;
221			break;
222		default:
223			if (!fflag &&
224			    !check(p->fts_path, p->fts_accpath, p->fts_statp))
225				continue;
226		}
227
228		rval = 0;
229		if (!uid &&
230		    (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
231		    !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
232			rval = chflags(p->fts_accpath,
233				       p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
234		if (!rval) {
235			/*
236			 * If we can't read or search the directory, may still be
237			 * able to remove it.  Don't print out the un{read,search}able
238			 * message unless the remove fails.
239			 */
240			switch (p->fts_info) {
241			case FTS_DP:
242			case FTS_DNR:
243				if (!rmdir(p->fts_accpath) || (fflag && errno == ENOENT))
244					continue;
245				break;
246
247#ifndef BSD4_4_LITE
248			case FTS_W:
249				if (!undelete(p->fts_accpath) ||
250			    	fflag && errno == ENOENT)
251					continue;
252				break;
253#endif
254
255			default:
256				if (Pflag)
257					rm_overwrite(p->fts_accpath, NULL);
258				if (!unlink(p->fts_accpath) || (fflag && errno == ENOENT))
259					continue;
260			}
261		}
262err:
263		warn("%s", p->fts_path);
264		eval = 1;
265	}
266	if (errno)
267		err(1, "fts_read");
268}
269
270void
271rm_file(argv)
272	char **argv;
273{
274	struct stat sb;
275	int rval;
276	char *f;
277
278	/*
279	 * Remove a file.  POSIX 1003.2 states that, by default, attempting
280	 * to remove a directory is an error, so must always stat the file.
281	 */
282	while ((f = *argv++) != NULL) {
283		/* Assume if can't stat the file, can't unlink it. */
284		if (lstat(f, &sb)) {
285#ifdef BSD4_4_LITE
286			if (!fflag || errno != ENOENT) {
287				warn("%s", f);
288				eval = 1;
289 			}
290#else
291			if (Wflag) {
292				sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
293			} else {
294				if (!fflag || errno != ENOENT) {
295					warn("%s", f);
296					eval = 1;
297				}
298				continue;
299			}
300		} else if (Wflag) {
301			warnx("%s: %s", f, strerror(EEXIST));
302			eval = 1;
303#endif
304			continue;
305		}
306
307		if (S_ISDIR(sb.st_mode) && !dflag) {
308			warnx("%s: is a directory", f);
309			eval = 1;
310			continue;
311		}
312#ifdef BSD4_4_LITE
313		if (!fflag && !check(f, f, &sb))
314#else
315		if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
316#endif
317			continue;
318		rval = 0;
319		if (!uid &&
320		    (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
321		    !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
322			rval = chflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
323		if (!rval) {
324#ifdef BSD4_4_LITE
325			if (S_ISDIR(sb.st_mode))
326#else
327			if (S_ISWHT(sb.st_mode))
328				rval = undelete(f);
329			else if (S_ISDIR(sb.st_mode))
330#endif
331				rval = rmdir(f);
332			else {
333				if (Pflag)
334					rm_overwrite(f, &sb);
335				rval = unlink(f);
336			}
337		}
338		if (rval && (!fflag || errno != ENOENT)) {
339			warn("%s", f);
340			eval = 1;
341		}
342	}
343}
344
345/*
346 * rm_overwrite --
347 *	Overwrite the file 3 times with varying bit patterns.
348 *
349 * XXX
350 * This is a cheap way to *really* delete files.  Note that only regular
351 * files are deleted, directories (and therefore names) will remain.
352 * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
353 * System V file system).  In a logging file system, you'll have to have
354 * kernel support.
355 */
356void
357rm_overwrite(file, sbp)
358	char *file;
359	struct stat *sbp;
360{
361	struct stat sb;
362	off_t len;
363	int fd, wlen;
364	char buf[8 * 1024];
365
366	fd = -1;
367	if (sbp == NULL) {
368		if (lstat(file, &sb))
369			goto err;
370		sbp = &sb;
371	}
372	if (!S_ISREG(sbp->st_mode))
373		return;
374	if ((fd = open(file, O_WRONLY, 0)) == -1)
375		goto err;
376
377#define	PASS(byte) {							\
378	memset(buf, byte, sizeof(buf));					\
379	for (len = sbp->st_size; len > 0; len -= wlen) {		\
380		wlen = len < sizeof(buf) ? len : sizeof(buf);		\
381		if (write(fd, buf, wlen) != wlen)			\
382			goto err;					\
383	}								\
384}
385	PASS(0xff);
386	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
387		goto err;
388	PASS(0x00);
389	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
390		goto err;
391	PASS(0xff);
392	if (!fsync(fd) && !close(fd))
393		return;
394
395err:	eval = 1;
396	warn("%s", file);
397}
398
399
400int
401check(path, name, sp)
402	char *path, *name;
403	struct stat *sp;
404{
405	int ch, first;
406	char modep[15], flagsp[128];
407
408	/* Check -i first. */
409	if (iflag)
410		(void)fprintf(stderr, "remove %s? ", path);
411	else {
412		/*
413		 * If it's not a symbolic link and it's unwritable and we're
414		 * talking to a terminal, ask.  Symbolic links are excluded
415		 * because their permissions are meaningless.  Check stdin_ok
416		 * first because we may not have stat'ed the file.
417		 */
418		if (!stdin_ok || S_ISLNK(sp->st_mode) ||
419		    (!access(name, W_OK) &&
420		    !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
421		    (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
422			return (1);
423		strmode(sp->st_mode, modep);
424		strcpy(flagsp, flags_to_string(sp->st_flags, NULL));
425		if (*flagsp)
426			strcat(flagsp, " ");
427		(void)fprintf(stderr, "override %s%s%s/%s %sfor %s? ",
428		    modep + 1, modep[9] == ' ' ? "" : " ",
429		    user_from_uid(sp->st_uid, 0),
430		    group_from_gid(sp->st_gid, 0),
431		    *flagsp ? flagsp : "",
432		    path);
433	}
434	(void)fflush(stderr);
435
436	first = ch = getchar();
437	while (ch != '\n' && ch != EOF)
438		ch = getchar();
439	return (first == 'y' || first == 'Y');
440}
441
442#define ISDOT(a)	((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
443void
444checkdot(argv)
445	char **argv;
446{
447	char *p, **save, **t;
448	int complained;
449
450	complained = 0;
451	for (t = argv; *t;) {
452		if ((p = strrchr(*t, '/')) != NULL)
453			++p;
454		else
455			p = *t;
456		if (ISDOT(p)) {
457			if (!complained++)
458				warnx("\".\" and \"..\" may not be removed");
459			eval = 1;
460			for (save = t; (t[0] = t[1]) != NULL; ++t)
461				continue;
462			t = save;
463		} else
464			++t;
465	}
466}
467
468void
469usage()
470{
471
472#ifdef BSD4_4_LITE
473	(void)fprintf(stderr, "usage: rm [-f | -i] [-dPRr] file ...\n");
474#else
475	(void)fprintf(stderr, "usage: rm [-f | -i] [-dPRrW] file ...\n");
476#endif
477	exit(1);
478}
479