xref: /netbsd-src/bin/rm/rm.c (revision ae9172d6cd9432a6a1a56760d86b32c57a66c39c)
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[] = "from: @(#)rm.c	8.5 (Berkeley) 4/18/94";*/
42 static char *rcsid = "$Id: rm.c,v 1.16 1994/11/02 16:17:14 jtc Exp $";
43 #endif /* not lint */
44 
45 #include <sys/types.h>
46 #include <sys/stat.h>
47 
48 #include <locale.h>
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 	setlocale(LC_ALL, "");
82 
83 	Pflag = rflag = 0;
84 	while ((ch = getopt(argc, argv, "dfiPRr")) != -1)
85 		switch(ch) {
86 		case 'd':
87 			dflag = 1;
88 			break;
89 		case 'f':
90 			fflag = 1;
91 			iflag = 0;
92 			break;
93 		case 'i':
94 			fflag = 0;
95 			iflag = 1;
96 			break;
97 		case 'P':
98 			Pflag = 1;
99 			break;
100 		case 'R':
101 		case 'r':			/* Compatibility. */
102 			rflag = 1;
103 			break;
104 		case '?':
105 		default:
106 			usage();
107 		}
108 	argc -= optind;
109 	argv += optind;
110 
111 	if (argc < 1)
112 		usage();
113 
114 	checkdot(argv);
115 
116 	if (*argv) {
117 		stdin_ok = isatty(STDIN_FILENO);
118 
119 		if (rflag)
120 			rm_tree(argv);
121 		else
122 			rm_file(argv);
123 	}
124 
125 	exit (eval);
126 }
127 
128 void
129 rm_tree(argv)
130 	char **argv;
131 {
132 	FTS *fts;
133 	FTSENT *p;
134 	int needstat;
135 
136 	/*
137 	 * Remove a file hierarchy.  If forcing removal (-f), or interactive
138 	 * (-i) or can't ask anyway (stdin_ok), don't stat the file.
139 	 */
140 	needstat = !fflag && !iflag && stdin_ok;
141 
142 	/*
143 	 * If the -i option is specified, the user can skip on the pre-order
144 	 * visit.  The fts_number field flags skipped directories.
145 	 */
146 #define	SKIPPED	1
147 
148 	if (!(fts = fts_open(argv,
149 	    needstat ? FTS_PHYSICAL : FTS_PHYSICAL|FTS_NOSTAT,
150 	    (int (*)())NULL)))
151 		err(1, NULL);
152 	while ((p = fts_read(fts)) != NULL) {
153 		switch (p->fts_info) {
154 		case FTS_DNR:
155 			if (!fflag || p->fts_errno != ENOENT) {
156 				warnx("%s: %s",
157 				    p->fts_path, strerror(p->fts_errno));
158 				eval = 1;
159 			}
160 			continue;
161 		case FTS_ERR:
162 			errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
163 		case FTS_NS:
164 			/*
165 			 * FTS_NS: assume that if can't stat the file, it
166 			 * can't be unlinked.
167 			 */
168 			if (!needstat)
169 				break;
170 			if (!fflag || p->fts_errno != ENOENT) {
171 				warnx("%s: %s",
172 				    p->fts_path, strerror(p->fts_errno));
173 				eval = 1;
174 			}
175 			continue;
176 		case FTS_D:
177 			/* Pre-order: give user chance to skip. */
178 			if (!fflag && !check(p->fts_path, p->fts_accpath,
179 			    p->fts_statp)) {
180 				(void)fts_set(fts, p, FTS_SKIP);
181 				p->fts_number = SKIPPED;
182 			}
183 			continue;
184 		case FTS_DP:
185 			/* Post-order: see if user skipped. */
186 			if (p->fts_number == SKIPPED)
187 				continue;
188 			break;
189 		default:
190 			if (!fflag &&
191 			    !check(p->fts_path, p->fts_accpath, p->fts_statp))
192 				continue;
193 		}
194 
195 		/*
196 		 * If we can't read or search the directory, may still be
197 		 * able to remove it.  Don't print out the un{read,search}able
198 		 * message unless the remove fails.
199 		 */
200 		if (p->fts_info == FTS_DP || p->fts_info == FTS_DNR) {
201 			if (!rmdir(p->fts_accpath) || fflag && errno == ENOENT)
202 				continue;
203 		} else {
204 			if (Pflag)
205 				rm_overwrite(p->fts_accpath, NULL);
206 			if (!unlink(p->fts_accpath) || fflag && errno == ENOENT)
207 				continue;
208 		}
209 		warn("%s", p->fts_path);
210 		eval = 1;
211 	}
212 	if (errno)
213 		err(1, "fts_read");
214 }
215 
216 void
217 rm_file(argv)
218 	char **argv;
219 {
220 	struct stat sb;
221 	int rval;
222 	char *f;
223 
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) && !dflag) {
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' || first == 'Y');
345 }
346 
347 
348 /*
349  * POSIX.2 requires that if "." or ".." are specified as the basename
350  * portion of an operand, a diagnostic message be written to standard
351  * error and nothing more be done with such operands.
352  *
353  * Since POSIX.2 defines basename as the final portion of a path after
354  * trailing slashes have been removed, we'll remove them here.
355  */
356 
357 #define ISDOT(a)	((a)[0] == '.' && (!(a)[1] || (a)[1] == '.' && !(a)[2]))
358 void
359 checkdot(argv)
360 	char **argv;
361 {
362 	char *p, **save, **t;
363 	int complained;
364 
365 	complained = 0;
366 	for (t = argv; *t;) {
367 		/* strip trailing slashes */
368 		p = strrchr (*t, '\0');
369 		while (--p > *t && *p == '/')
370 			*p = '\0';
371 
372 		/* extract basename */
373 		if ((p = strrchr(*t, '/')) != NULL)
374 			++p;
375 		else
376 			p = *t;
377 
378 		if (ISDOT(p)) {
379 			if (!complained++)
380 				warnx("\".\" and \"..\" may not be removed");
381 			eval = 1;
382 			for (save = t; (t[0] = t[1]) != NULL; ++t)
383 				continue;
384 			t = save;
385 		} else
386 			++t;
387 	}
388 }
389 
390 void
391 usage()
392 {
393 
394 	(void)fprintf(stderr, "usage: rm [-dfiPRr] file ...\n");
395 	exit(1);
396 }
397