xref: /freebsd/bin/rm/rm.c (revision 417ed37975261df51f61d13e179ad04d8f4839c7)
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  *	$Id$
34  */
35 
36 #ifndef lint
37 static char 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
43 static char 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 int dflag, eval, fflag, iflag, Pflag, stdin_ok;
59 
60 int	check __P((char *, char *, struct stat *));
61 void	checkdot __P((char **));
62 void	rm_file __P((char **));
63 void	rm_overwrite __P((char *, struct stat *));
64 void	rm_tree __P((char **));
65 void	usage __P((void));
66 
67 /*
68  * rm --
69  *	This rm is different from historic rm's, but is expected to match
70  *	POSIX 1003.2 behavior.  The most visible difference is that -f
71  *	has two specific effects now, ignore non-existent files and force
72  * 	file removal.
73  */
74 int
75 main(argc, argv)
76 	int argc;
77 	char *argv[];
78 {
79 	int ch, rflag;
80 
81 	Pflag = rflag = 0;
82 	while ((ch = getopt(argc, argv, "dfiPRr")) != EOF)
83 		switch(ch) {
84 		case 'd':
85 			dflag = 1;
86 			break;
87 		case 'f':
88 			fflag = 1;
89 			iflag = 0;
90 			break;
91 		case 'i':
92 			fflag = 0;
93 			iflag = 1;
94 			break;
95 		case 'P':
96 			Pflag = 1;
97 			break;
98 		case 'R':
99 		case 'r':			/* Compatibility. */
100 			rflag = 1;
101 			break;
102 		case '?':
103 		default:
104 			usage();
105 		}
106 	argc -= optind;
107 	argv += optind;
108 
109 	if (argc < 1)
110 		usage();
111 
112 	checkdot(argv);
113 	if (!*argv)
114 		exit (eval);
115 
116 	stdin_ok = isatty(STDIN_FILENO);
117 
118 	if (rflag)
119 		rm_tree(argv);
120 	else
121 		rm_file(argv);
122 	exit (eval);
123 }
124 
125 void
126 rm_tree(argv)
127 	char **argv;
128 {
129 	FTS *fts;
130 	FTSENT *p;
131 	int needstat;
132 
133 	/*
134 	 * Remove a file hierarchy.  If forcing removal (-f), or interactive
135 	 * (-i) or can't ask anyway (stdin_ok), don't stat the file.
136 	 */
137 	needstat = !fflag && !iflag && stdin_ok;
138 
139 	/*
140 	 * If the -i option is specified, the user can skip on the pre-order
141 	 * visit.  The fts_number field flags skipped directories.
142 	 */
143 #define	SKIPPED	1
144 
145 	if (!(fts = fts_open(argv,
146 	    needstat ? FTS_PHYSICAL|FTS_NOCHDIR :
147 		FTS_PHYSICAL|FTS_NOSTAT|FTS_NOCHDIR, (int (*)())NULL)))
148 		err(1, NULL);
149 	while ((p = fts_read(fts)) != NULL) {
150 		switch (p->fts_info) {
151 		case FTS_DNR:
152 			if (!fflag || p->fts_errno != ENOENT) {
153 				warnx("%s: %s",
154 				    p->fts_path, strerror(p->fts_errno));
155 				eval = 1;
156 			}
157 			continue;
158 		case FTS_ERR:
159 			errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
160 		case FTS_NS:
161 			/*
162 			 * FTS_NS: assume that if can't stat the file, it
163 			 * can't be unlinked.
164 			 */
165 			if (!needstat)
166 				break;
167 			if (!fflag || p->fts_errno != ENOENT) {
168 				warnx("%s: %s",
169 				    p->fts_path, strerror(p->fts_errno));
170 				eval = 1;
171 			}
172 			continue;
173 		case FTS_D:
174 			/* Pre-order: give user chance to skip. */
175 			if (iflag && !check(p->fts_path, p->fts_accpath,
176 			    p->fts_statp)) {
177 				(void)fts_set(fts, p, FTS_SKIP);
178 				p->fts_number = SKIPPED;
179 			}
180 			continue;
181 		case FTS_DP:
182 			/* Post-order: see if user skipped. */
183 			if (p->fts_number == SKIPPED)
184 				continue;
185 			break;
186 		}
187 		if (!fflag &&
188 		    !check(p->fts_path, p->fts_accpath, p->fts_statp))
189 			continue;
190 
191 		/*
192 		 * If we can't read or search the directory, may still be
193 		 * able to remove it.  Don't print out the un{read,search}able
194 		 * message unless the remove fails.
195 		 */
196 		if (p->fts_info == FTS_DP || p->fts_info == FTS_DNR) {
197 			if (!rmdir(p->fts_accpath))
198 				continue;
199 			if (errno == ENOENT) {
200 				if (fflag)
201 					continue;
202 			} else if (p->fts_info != FTS_DP)
203 				warnx("%s: unable to read", p->fts_path);
204 		} else {
205 			if (Pflag)
206 				rm_overwrite(p->fts_accpath, NULL);
207 			if (!unlink(p->fts_accpath) || (fflag && errno == ENOENT))
208 				continue;
209 		}
210 		warn("%s", p->fts_path);
211 		eval = 1;
212 	}
213 	if (errno)
214 		err(1, "fts_read");
215 }
216 
217 void
218 rm_file(argv)
219 	char **argv;
220 {
221 	struct stat sb;
222 	int df, rval;
223 	char *f;
224 
225 	df = dflag;
226 	/*
227 	 * Remove a file.  POSIX 1003.2 states that, by default, attempting
228 	 * to remove a directory is an error, so must always stat the file.
229 	 */
230 	while ((f = *argv++) != NULL) {
231 		/* Assume if can't stat the file, can't unlink it. */
232 		if (lstat(f, &sb)) {
233 			if (!fflag || errno != ENOENT) {
234 				warn("%s", f);
235 				eval = 1;
236 			}
237 			continue;
238 		}
239 		if (S_ISDIR(sb.st_mode) && !df) {
240 			warnx("%s: is a directory", f);
241 			eval = 1;
242 			continue;
243 		}
244 		if (!fflag && !check(f, f, &sb))
245 			continue;
246 		if (S_ISDIR(sb.st_mode))
247 			rval = rmdir(f);
248 		else {
249 			if (Pflag)
250 				rm_overwrite(f, &sb);
251 			rval = unlink(f);
252 		}
253 		if (rval && (!fflag || errno != ENOENT)) {
254 			warn("%s", f);
255 			eval = 1;
256 		}
257 	}
258 }
259 
260 /*
261  * rm_overwrite --
262  *	Overwrite the file 3 times with varying bit patterns.
263  *
264  * XXX
265  * This is a cheap way to *really* delete files.  Note that only regular
266  * files are deleted, directories (and therefore names) will remain.
267  * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
268  * System V file system).  In a logging file system, you'll have to have
269  * kernel support.
270  */
271 void
272 rm_overwrite(file, sbp)
273 	char *file;
274 	struct stat *sbp;
275 {
276 	struct stat sb;
277 	off_t len;
278 	int fd, wlen;
279 	char buf[8 * 1024];
280 
281 	fd = -1;
282 	if (sbp == NULL) {
283 		if (lstat(file, &sb))
284 			goto err;
285 		sbp = &sb;
286 	}
287 	if (!S_ISREG(sbp->st_mode))
288 		return;
289 	if ((fd = open(file, O_WRONLY, 0)) == -1)
290 		goto err;
291 
292 #define	PASS(byte) {							\
293 	memset(buf, byte, sizeof(buf));					\
294 	for (len = sbp->st_size; len > 0; len -= wlen) {		\
295 		wlen = len < sizeof(buf) ? len : sizeof(buf);		\
296 		if (write(fd, buf, wlen) != wlen)			\
297 			goto err;					\
298 	}								\
299 }
300 	PASS(0xff);
301 	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
302 		goto err;
303 	PASS(0x00);
304 	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
305 		goto err;
306 	PASS(0xff);
307 	if (!fsync(fd) && !close(fd))
308 		return;
309 
310 err:	eval = 1;
311 	warn("%s", file);
312 }
313 
314 
315 int
316 check(path, name, sp)
317 	char *path, *name;
318 	struct stat *sp;
319 {
320 	int ch, first;
321 	char modep[15];
322 
323 	/* Check -i first. */
324 	if (iflag)
325 		(void)fprintf(stderr, "remove %s? ", path);
326 	else {
327 		/*
328 		 * If it's not a symbolic link and it's unwritable and we're
329 		 * talking to a terminal, ask.  Symbolic links are excluded
330 		 * because their permissions are meaningless.  Check stdin_ok
331 		 * first because we may not have stat'ed the file.
332 		 */
333 		if (!stdin_ok || S_ISLNK(sp->st_mode) || !access(name, W_OK))
334 			return (1);
335 		strmode(sp->st_mode, modep);
336 		(void)fprintf(stderr, "override %s%s%s/%s for %s? ",
337 		    modep + 1, modep[9] == ' ' ? "" : " ",
338 		    user_from_uid(sp->st_uid, 0),
339 		    group_from_gid(sp->st_gid, 0), path);
340 	}
341 	(void)fflush(stderr);
342 
343 	first = ch = getchar();
344 	while (ch != '\n' && ch != EOF)
345 		ch = getchar();
346 	return (first == 'y');
347 }
348 
349 #define ISDOT(a)	((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
350 void
351 checkdot(argv)
352 	char **argv;
353 {
354 	char *p, **save, **t;
355 	int complained;
356 
357 	complained = 0;
358 	for (t = argv; *t;) {
359 		if ((p = strrchr(*t, '/')) != NULL)
360 			++p;
361 		else
362 			p = *t;
363 		if (ISDOT(p)) {
364 			if (!complained++)
365 				warnx("\".\" and \"..\" may not be removed");
366 			eval = 1;
367 			for (save = t; (t[0] = t[1]) != NULL; ++t);
368 			t = save;
369 		} else
370 			++t;
371 	}
372 }
373 
374 void
375 usage()
376 {
377 
378 	(void)fprintf(stderr, "usage: rm [-dfiRr] file ...\n");
379 	exit(1);
380 }
381