rm.c revision 1.4 
1/*	$OpenBSD: rm.c,v 1.4 2015/11/17 19:09:06 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 <locale.h>
38#include <err.h>
39#include <errno.h>
40#include <fcntl.h>
41#include <fts.h>
42#include <stdio.h>
43#include <stdlib.h>
44#include <string.h>
45#include <unistd.h>
46#include <limits.h>
47#include <pwd.h>
48#include <grp.h>
49
50#define MAXIMUM(a, b)	(((a) > (b)) ? (a) : (b))
51
52extern char *__progname;
53
54static int eval, stdin_ok;
55
56static int	check(char *, char *, struct stat *);
57static void	checkdot(char **);
58static void	rm_file(char **);
59static void	rm_tree(char **);
60
61static void __dead
62usage(void)
63{
64	(void)fprintf(stderr, "usage: %s [-dfiPRr] file ...\n", __progname);
65	exit(1);
66}
67
68/*
69 * rm --
70 *	This rm is different from historic rm's, but is expected to match
71 *	POSIX 1003.2 behavior.  The most visible difference is that -f
72 *	has two specific effects now, ignore non-existent files and force
73 * 	file removal.
74 */
75int
76rmmain(int argc, char *argv[])
77{
78	if (pledge("stdio rpath cpath", NULL) == -1)
79		err(1, "pledge");
80
81	checkdot(argv);
82
83	if (*argv) {
84		stdin_ok = isatty(STDIN_FILENO);
85
86		rm_tree(argv);
87	}
88
89	return (eval);
90}
91
92static void
93rm_tree(char **argv)
94{
95	FTS *fts;
96	FTSENT *p;
97	int flags;
98
99	/*
100	 * If the -i option is specified, the user can skip on the pre-order
101	 * visit.  The fts_number field flags skipped directories.
102	 */
103#define	SKIPPED	1
104
105	flags = FTS_PHYSICAL;
106	flags |= FTS_NOSTAT;
107	if (!(fts = fts_open(argv, flags, NULL)))
108		err(1, NULL);
109	while ((p = fts_read(fts)) != NULL) {
110		switch (p->fts_info) {
111		case FTS_DNR:
112			if (p->fts_errno != ENOENT) {
113				warnx("%s: %s",
114				    p->fts_path, strerror(p->fts_errno));
115				eval = 1;
116			}
117			continue;
118		case FTS_ERR:
119			errc(1, p->fts_errno, "%s", p->fts_path);
120		case FTS_NS:
121			/*
122			 * FTS_NS: assume that if can't stat the file, it
123			 * can't be unlinked.
124			 */
125			break;
126		case FTS_D:
127			/* Pre-order: give user chance to skip. */
128			continue;
129		case FTS_DP:
130			/* Post-order: see if user skipped. */
131			if (p->fts_number == SKIPPED)
132				continue;
133			break;
134		default:
135			break;
136		}
137
138		/*
139		 * If we can't read or search the directory, may still be
140		 * able to remove it.  Don't print out the un{read,search}able
141		 * message unless the remove fails.
142		 */
143		switch (p->fts_info) {
144		case FTS_DP:
145		case FTS_DNR:
146			if (!rmdir(p->fts_accpath) ||
147			    (errno == ENOENT))
148				continue;
149			break;
150
151		case FTS_F:
152		case FTS_NSOK:
153		default:
154			if (!unlink(p->fts_accpath) ||
155			    (errno == ENOENT))
156				continue;
157		}
158		warn("%s", p->fts_path);
159		eval = 1;
160	}
161	if (errno)
162		err(1, "fts_read");
163	fts_close(fts);
164}
165
166static void
167rm_file(char **argv)
168{
169	struct stat sb;
170	int rval;
171	char *f;
172
173	/*
174	 * Remove a file.  POSIX 1003.2 states that, by default, attempting
175	 * to remove a directory is an error, so must always stat the file.
176	 */
177	while ((f = *argv++) != NULL) {
178		/* Assume if can't stat the file, can't unlink it. */
179		if (lstat(f, &sb)) {
180			if (errno != ENOENT) {
181				warn("%s", f);
182				eval = 1;
183			}
184			continue;
185		}
186
187		if (S_ISDIR(sb.st_mode)) {
188			warnx("%s: is a directory", f);
189			eval = 1;
190			continue;
191		}
192		if (S_ISDIR(sb.st_mode))
193			rval = rmdir(f);
194		else {
195			rval = unlink(f);
196		}
197		if (rval && (errno != ENOENT)) {
198			warn("%s", f);
199			eval = 1;
200		}
201	}
202}
203
204static int
205check(char *path, char *name, struct stat *sp)
206{
207	int ch, first;
208	char modep[15];
209
210	/*
211	 * If it's not a symbolic link and it's unwritable and we're
212	 * talking to a terminal, ask.  Symbolic links are excluded
213	 * because their permissions are meaningless.  Check stdin_ok
214	 * first because we may not have stat'ed the file.
215	 */
216	if (!stdin_ok || S_ISLNK(sp->st_mode) || !access(name, W_OK) ||
217	    errno != EACCES)
218		return (1);
219	strmode(sp->st_mode, modep);
220	(void)fprintf(stderr, "override %s%s%s/%s for %s? ",
221	    modep + 1, modep[9] == ' ' ? "" : " ",
222	    user_from_uid(sp->st_uid, 0),
223	    group_from_gid(sp->st_gid, 0), path);
224	(void)fflush(stderr);
225
226	first = ch = getchar();
227	while (ch != '\n' && ch != EOF)
228		ch = getchar();
229	return (first == 'y' || first == 'Y');
230}
231
232/*
233 * POSIX.2 requires that if "." or ".." are specified as the basename
234 * portion of an operand, a diagnostic message be written to standard
235 * error and nothing more be done with such operands.
236 *
237 * Since POSIX.2 defines basename as the final portion of a path after
238 * trailing slashes have been removed, we'll remove them here.
239 */
240#define ISDOT(a)	((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
241static void
242checkdot(char **argv)
243{
244	char *p, **save, **t;
245	int complained;
246
247	complained = 0;
248	for (t = argv; *t;) {
249		/* strip trailing slashes */
250		p = strrchr (*t, '\0');
251		while (--p > *t && *p == '/')
252			*p = '\0';
253
254		/* extract basename */
255		if ((p = strrchr(*t, '/')) != NULL)
256			++p;
257		else
258			p = *t;
259
260		if (ISDOT(p)) {
261			if (!complained++)
262				warnx("\".\" and \"..\" may not be removed");
263			eval = 1;
264			for (save = t; (t[0] = t[1]) != NULL; ++t)
265				continue;
266			t = save;
267		} else
268			++t;
269	}
270}
271