xref: /freebsd/bin/rm/rm.c (revision afe61c15161c324a7af299a9b8457aba5afc92db)
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
35 static 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 static char sccsid[] = "@(#)rm.c	8.5 (Berkeley) 4/18/94";
42 #endif /* not lint */
43 
44 #include <sys/types.h>
45 #include <sys/stat.h>
46 
47 #include <err.h>
48 #include <errno.h>
49 #include <fcntl.h>
50 #include <fts.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <unistd.h>
55 
56 int dflag, eval, fflag, iflag, Pflag, stdin_ok;
57 
58 int	check __P((char *, char *, struct stat *));
59 void	checkdot __P((char **));
60 void	rm_file __P((char **));
61 void	rm_overwrite __P((char *, struct stat *));
62 void	rm_tree __P((char **));
63 void	usage __P((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(argc, argv)
74 	int argc;
75 	char *argv[];
76 {
77 	int ch, rflag;
78 
79 	Pflag = rflag = 0;
80 	while ((ch = getopt(argc, argv, "dfiPRr")) != EOF)
81 		switch(ch) {
82 		case 'd':
83 			dflag = 1;
84 			break;
85 		case 'f':
86 			fflag = 1;
87 			iflag = 0;
88 			break;
89 		case 'i':
90 			fflag = 0;
91 			iflag = 1;
92 			break;
93 		case 'P':
94 			Pflag = 1;
95 			break;
96 		case 'R':
97 		case 'r':			/* Compatibility. */
98 			rflag = 1;
99 			break;
100 		case '?':
101 		default:
102 			usage();
103 		}
104 	argc -= optind;
105 	argv += optind;
106 
107 	if (argc < 1)
108 		usage();
109 
110 	checkdot(argv);
111 	if (!*argv)
112 		exit (eval);
113 
114 	stdin_ok = isatty(STDIN_FILENO);
115 
116 	if (rflag)
117 		rm_tree(argv);
118 	else
119 		rm_file(argv);
120 	exit (eval);
121 }
122 
123 void
124 rm_tree(argv)
125 	char **argv;
126 {
127 	FTS *fts;
128 	FTSENT *p;
129 	int needstat;
130 
131 	/*
132 	 * Remove a file hierarchy.  If forcing removal (-f), or interactive
133 	 * (-i) or can't ask anyway (stdin_ok), don't stat the file.
134 	 */
135 	needstat = !fflag && !iflag && stdin_ok;
136 
137 	/*
138 	 * If the -i option is specified, the user can skip on the pre-order
139 	 * visit.  The fts_number field flags skipped directories.
140 	 */
141 #define	SKIPPED	1
142 
143 	if (!(fts = fts_open(argv,
144 	    needstat ? FTS_PHYSICAL : FTS_PHYSICAL|FTS_NOSTAT,
145 	    (int (*)())NULL)))
146 		err(1, NULL);
147 	while ((p = fts_read(fts)) != NULL) {
148 		switch (p->fts_info) {
149 		case FTS_DNR:
150 			if (!fflag || p->fts_errno != ENOENT) {
151 				warnx("%s: %s",
152 				    p->fts_path, strerror(p->fts_errno));
153 				eval = 1;
154 			}
155 			continue;
156 		case FTS_ERR:
157 			errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
158 		case FTS_NS:
159 			/*
160 			 * FTS_NS: assume that if can't stat the file, it
161 			 * can't be unlinked.
162 			 */
163 			if (!needstat)
164 				break;
165 			if (!fflag || p->fts_errno != ENOENT) {
166 				warnx("%s: %s",
167 				    p->fts_path, strerror(p->fts_errno));
168 				eval = 1;
169 			}
170 			continue;
171 		case FTS_D:
172 			/* Pre-order: give user chance to skip. */
173 			if (iflag && !check(p->fts_path, p->fts_accpath,
174 			    p->fts_statp)) {
175 				(void)fts_set(fts, p, FTS_SKIP);
176 				p->fts_number = SKIPPED;
177 			}
178 			continue;
179 		case FTS_DP:
180 			/* Post-order: see if user skipped. */
181 			if (p->fts_number == SKIPPED)
182 				continue;
183 			break;
184 		}
185 		if (!fflag &&
186 		    !check(p->fts_path, p->fts_accpath, p->fts_statp))
187 			continue;
188 
189 		/*
190 		 * If we can't read or search the directory, may still be
191 		 * able to remove it.  Don't print out the un{read,search}able
192 		 * message unless the remove fails.
193 		 */
194 		if (p->fts_info == FTS_DP || p->fts_info == FTS_DNR) {
195 			if (!rmdir(p->fts_accpath))
196 				continue;
197 			if (errno == ENOENT) {
198 				if (fflag)
199 					continue;
200 			} else if (p->fts_info != FTS_DP)
201 				warnx("%s: unable to read", p->fts_path);
202 		} else {
203 			if (Pflag)
204 				rm_overwrite(p->fts_accpath, NULL);
205 			if (!unlink(p->fts_accpath) || fflag && errno == ENOENT)
206 				continue;
207 		}
208 		warn("%s", p->fts_path);
209 		eval = 1;
210 	}
211 	if (errno)
212 		err(1, "fts_read");
213 }
214 
215 void
216 rm_file(argv)
217 	char **argv;
218 {
219 	struct stat sb;
220 	int df, rval;
221 	char *f;
222 
223 	df = dflag;
224 	/*
225 	 * Remove a file.  POSIX 1003.2 states that, by default, attempting
226 	 * to remove a directory is an error, so must always stat the file.
227 	 */
228 	while ((f = *argv++) != NULL) {
229 		/* Assume if can't stat the file, can't unlink it. */
230 		if (lstat(f, &sb)) {
231 			if (!fflag || errno != ENOENT) {
232 				warn("%s", f);
233 				eval = 1;
234 			}
235 			continue;
236 		}
237 		if (S_ISDIR(sb.st_mode) && !df) {
238 			warnx("%s: is a directory", f);
239 			eval = 1;
240 			continue;
241 		}
242 		if (!fflag && !check(f, f, &sb))
243 			continue;
244 		if (S_ISDIR(sb.st_mode))
245 			rval = rmdir(f);
246 		else {
247 			if (Pflag)
248 				rm_overwrite(f, &sb);
249 			rval = unlink(f);
250 		}
251 		if (rval && (!fflag || errno != ENOENT)) {
252 			warn("%s", f);
253 			eval = 1;
254 		}
255 	}
256 }
257 
258 /*
259  * rm_overwrite --
260  *	Overwrite the file 3 times with varying bit patterns.
261  *
262  * XXX
263  * This is a cheap way to *really* delete files.  Note that only regular
264  * files are deleted, directories (and therefore names) will remain.
265  * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
266  * System V file system).  In a logging file system, you'll have to have
267  * kernel support.
268  */
269 void
270 rm_overwrite(file, sbp)
271 	char *file;
272 	struct stat *sbp;
273 {
274 	struct stat sb;
275 	off_t len;
276 	int fd, wlen;
277 	char buf[8 * 1024];
278 
279 	fd = -1;
280 	if (sbp == NULL) {
281 		if (lstat(file, &sb))
282 			goto err;
283 		sbp = &sb;
284 	}
285 	if (!S_ISREG(sbp->st_mode))
286 		return;
287 	if ((fd = open(file, O_WRONLY, 0)) == -1)
288 		goto err;
289 
290 #define	PASS(byte) {							\
291 	memset(buf, byte, sizeof(buf));					\
292 	for (len = sbp->st_size; len > 0; len -= wlen) {		\
293 		wlen = len < sizeof(buf) ? len : sizeof(buf);		\
294 		if (write(fd, buf, wlen) != wlen)			\
295 			goto err;					\
296 	}								\
297 }
298 	PASS(0xff);
299 	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
300 		goto err;
301 	PASS(0x00);
302 	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
303 		goto err;
304 	PASS(0xff);
305 	if (!fsync(fd) && !close(fd))
306 		return;
307 
308 err:	eval = 1;
309 	warn("%s", file);
310 }
311 
312 
313 int
314 check(path, name, sp)
315 	char *path, *name;
316 	struct stat *sp;
317 {
318 	int ch, first;
319 	char modep[15];
320 
321 	/* Check -i first. */
322 	if (iflag)
323 		(void)fprintf(stderr, "remove %s? ", path);
324 	else {
325 		/*
326 		 * If it's not a symbolic link and it's unwritable and we're
327 		 * talking to a terminal, ask.  Symbolic links are excluded
328 		 * because their permissions are meaningless.  Check stdin_ok
329 		 * first because we may not have stat'ed the file.
330 		 */
331 		if (!stdin_ok || S_ISLNK(sp->st_mode) || !access(name, W_OK))
332 			return (1);
333 		strmode(sp->st_mode, modep);
334 		(void)fprintf(stderr, "override %s%s%s/%s for %s? ",
335 		    modep + 1, modep[9] == ' ' ? "" : " ",
336 		    user_from_uid(sp->st_uid, 0),
337 		    group_from_gid(sp->st_gid, 0), path);
338 	}
339 	(void)fflush(stderr);
340 
341 	first = ch = getchar();
342 	while (ch != '\n' && ch != EOF)
343 		ch = getchar();
344 	return (first == 'y');
345 }
346 
347 #define ISDOT(a)	((a)[0] == '.' && (!(a)[1] || (a)[1] == '.' && !(a)[2]))
348 void
349 checkdot(argv)
350 	char **argv;
351 {
352 	char *p, **save, **t;
353 	int complained;
354 
355 	complained = 0;
356 	for (t = argv; *t;) {
357 		if ((p = strrchr(*t, '/')) != NULL)
358 			++p;
359 		else
360 			p = *t;
361 		if (ISDOT(p)) {
362 			if (!complained++)
363 				warnx("\".\" and \"..\" may not be removed");
364 			eval = 1;
365 			for (save = t; (t[0] = t[1]) != NULL; ++t);
366 			t = save;
367 		} else
368 			++t;
369 	}
370 }
371 
372 void
373 usage()
374 {
375 
376 	(void)fprintf(stderr, "usage: rm [-dfiRr] file ...\n");
377 	exit(1);
378 }
379