rm.c revision 1.5 
1/*	$OpenBSD: rm.c,v 1.5 2015/11/17 19:11:11 tedu Exp $	*/
2/*	$NetBSD: rm.c,v 1.19 1995/09/07 06:48:50 jtc Exp $	*/
3
4/*-
5 * Copyright (c) 1990, 1993, 1994
6 *	The Regents of the University of California.  All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <sys/types.h>
34#include <sys/stat.h>
35#include <sys/mount.h>
36
37#include <err.h>
38#include <errno.h>
39#include <fcntl.h>
40#include <fts.h>
41#include <stdio.h>
42#include <stdlib.h>
43#include <string.h>
44#include <unistd.h>
45#include <limits.h>
46#include <pwd.h>
47#include <grp.h>
48
49#define MAXIMUM(a, b)	(((a) > (b)) ? (a) : (b))
50
51extern char *__progname;
52
53static int eval, stdin_ok;
54
55static int	check(char *, char *, struct stat *);
56static void	checkdot(char **);
57static void	rm_file(char **);
58static void	rm_tree(char **);
59
60static void __dead
61usage(void)
62{
63	(void)fprintf(stderr, "usage: %s [-dfiPRr] file ...\n", __progname);
64	exit(1);
65}
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 */
74int
75rmmain(int argc, char *argv[])
76{
77	if (pledge("stdio rpath cpath", NULL) == -1)
78		err(1, "pledge");
79
80	checkdot(argv);
81
82	if (*argv) {
83		stdin_ok = isatty(STDIN_FILENO);
84
85		rm_tree(argv);
86	}
87
88	return (eval);
89}
90
91static void
92rm_tree(char **argv)
93{
94	FTS *fts;
95	FTSENT *p;
96	int flags;
97
98	/*
99	 * If the -i option is specified, the user can skip on the pre-order
100	 * visit.  The fts_number field flags skipped directories.
101	 */
102#define	SKIPPED	1
103
104	flags = FTS_PHYSICAL;
105	flags |= FTS_NOSTAT;
106	if (!(fts = fts_open(argv, flags, NULL)))
107		err(1, NULL);
108	while ((p = fts_read(fts)) != NULL) {
109		switch (p->fts_info) {
110		case FTS_DNR:
111			if (p->fts_errno != ENOENT) {
112				warnx("%s: %s",
113				    p->fts_path, strerror(p->fts_errno));
114				eval = 1;
115			}
116			continue;
117		case FTS_ERR:
118			errc(1, p->fts_errno, "%s", p->fts_path);
119		case FTS_NS:
120			/*
121			 * FTS_NS: assume that if can't stat the file, it
122			 * can't be unlinked.
123			 */
124			break;
125		case FTS_D:
126			/* Pre-order: give user chance to skip. */
127			continue;
128		case FTS_DP:
129			/* Post-order: see if user skipped. */
130			if (p->fts_number == SKIPPED)
131				continue;
132			break;
133		default:
134			break;
135		}
136
137		/*
138		 * If we can't read or search the directory, may still be
139		 * able to remove it.  Don't print out the un{read,search}able
140		 * message unless the remove fails.
141		 */
142		switch (p->fts_info) {
143		case FTS_DP:
144		case FTS_DNR:
145			if (!rmdir(p->fts_accpath) ||
146			    (errno == ENOENT))
147				continue;
148			break;
149
150		case FTS_F:
151		case FTS_NSOK:
152		default:
153			if (!unlink(p->fts_accpath) ||
154			    (errno == ENOENT))
155				continue;
156		}
157		warn("%s", p->fts_path);
158		eval = 1;
159	}
160	if (errno)
161		err(1, "fts_read");
162	fts_close(fts);
163}
164
165static void
166rm_file(char **argv)
167{
168	struct stat sb;
169	int rval;
170	char *f;
171
172	/*
173	 * Remove a file.  POSIX 1003.2 states that, by default, attempting
174	 * to remove a directory is an error, so must always stat the file.
175	 */
176	while ((f = *argv++) != NULL) {
177		/* Assume if can't stat the file, can't unlink it. */
178		if (lstat(f, &sb)) {
179			if (errno != ENOENT) {
180				warn("%s", f);
181				eval = 1;
182			}
183			continue;
184		}
185
186		if (S_ISDIR(sb.st_mode)) {
187			warnx("%s: is a directory", f);
188			eval = 1;
189			continue;
190		}
191		if (S_ISDIR(sb.st_mode))
192			rval = rmdir(f);
193		else {
194			rval = unlink(f);
195		}
196		if (rval && (errno != ENOENT)) {
197			warn("%s", f);
198			eval = 1;
199		}
200	}
201}
202
203static int
204check(char *path, char *name, struct stat *sp)
205{
206	int ch, first;
207	char modep[15];
208
209	/*
210	 * If it's not a symbolic link and it's unwritable and we're
211	 * talking to a terminal, ask.  Symbolic links are excluded
212	 * because their permissions are meaningless.  Check stdin_ok
213	 * first because we may not have stat'ed the file.
214	 */
215	if (!stdin_ok || S_ISLNK(sp->st_mode) || !access(name, W_OK) ||
216	    errno != EACCES)
217		return (1);
218	strmode(sp->st_mode, modep);
219	(void)fprintf(stderr, "override %s%s%s/%s for %s? ",
220	    modep + 1, modep[9] == ' ' ? "" : " ",
221	    user_from_uid(sp->st_uid, 0),
222	    group_from_gid(sp->st_gid, 0), path);
223	(void)fflush(stderr);
224
225	first = ch = getchar();
226	while (ch != '\n' && ch != EOF)
227		ch = getchar();
228	return (first == 'y' || first == 'Y');
229}
230
231/*
232 * POSIX.2 requires that if "." or ".." are specified as the basename
233 * portion of an operand, a diagnostic message be written to standard
234 * error and nothing more be done with such operands.
235 *
236 * Since POSIX.2 defines basename as the final portion of a path after
237 * trailing slashes have been removed, we'll remove them here.
238 */
239#define ISDOT(a)	((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
240static void
241checkdot(char **argv)
242{
243	char *p, **save, **t;
244	int complained;
245
246	complained = 0;
247	for (t = argv; *t;) {
248		/* strip trailing slashes */
249		p = strrchr (*t, '\0');
250		while (--p > *t && *p == '/')
251			*p = '\0';
252
253		/* extract basename */
254		if ((p = strrchr(*t, '/')) != NULL)
255			++p;
256		else
257			p = *t;
258
259		if (ISDOT(p)) {
260			if (!complained++)
261				warnx("\".\" and \"..\" may not be removed");
262			eval = 1;
263			for (save = t; (t[0] = t[1]) != NULL; ++t)
264				continue;
265			t = save;
266		} else
267			++t;
268	}
269}
270