rm.c revision 1.7 
1/*	$OpenBSD: rm.c,v 1.7 2015/11/27 17:32:16 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
78	checkdot(argv);
79
80	if (*argv) {
81		stdin_ok = isatty(STDIN_FILENO);
82
83		rm_tree(argv);
84	}
85
86	return (eval);
87}
88
89static void
90rm_tree(char **argv)
91{
92	FTS *fts;
93	FTSENT *p;
94	int flags;
95
96	/*
97	 * If the -i option is specified, the user can skip on the pre-order
98	 * visit.  The fts_number field flags skipped directories.
99	 */
100#define	SKIPPED	1
101
102	flags = FTS_PHYSICAL;
103	flags |= FTS_NOSTAT;
104	if (!(fts = fts_open(argv, flags, NULL)))
105		err(1, NULL);
106	while ((p = fts_read(fts)) != NULL) {
107		switch (p->fts_info) {
108		case FTS_DNR:
109			if (p->fts_errno != ENOENT) {
110				warnx("%s: %s",
111				    p->fts_path, strerror(p->fts_errno));
112				eval = 1;
113			}
114			continue;
115		case FTS_ERR:
116			errc(1, p->fts_errno, "%s", p->fts_path);
117		case FTS_NS:
118			/*
119			 * FTS_NS: assume that if can't stat the file, it
120			 * can't be unlinked.
121			 */
122			break;
123		case FTS_D:
124			/* Pre-order: give user chance to skip. */
125			continue;
126		case FTS_DP:
127			/* Post-order: see if user skipped. */
128			if (p->fts_number == SKIPPED)
129				continue;
130			break;
131		default:
132			break;
133		}
134
135		/*
136		 * If we can't read or search the directory, may still be
137		 * able to remove it.  Don't print out the un{read,search}able
138		 * message unless the remove fails.
139		 */
140		switch (p->fts_info) {
141		case FTS_DP:
142		case FTS_DNR:
143			if (!rmdir(p->fts_accpath) ||
144			    (errno == ENOENT))
145				continue;
146			break;
147
148		case FTS_F:
149		case FTS_NSOK:
150		default:
151			if (!unlink(p->fts_accpath) ||
152			    (errno == ENOENT))
153				continue;
154		}
155		warn("%s", p->fts_path);
156		eval = 1;
157	}
158	if (errno)
159		err(1, "fts_read");
160	fts_close(fts);
161}
162
163static void
164rm_file(char **argv)
165{
166	struct stat sb;
167	int rval;
168	char *f;
169
170	/*
171	 * Remove a file.  POSIX 1003.2 states that, by default, attempting
172	 * to remove a directory is an error, so must always stat the file.
173	 */
174	while ((f = *argv++) != NULL) {
175		/* Assume if can't stat the file, can't unlink it. */
176		if (lstat(f, &sb)) {
177			if (errno != ENOENT) {
178				warn("%s", f);
179				eval = 1;
180			}
181			continue;
182		}
183
184		if (S_ISDIR(sb.st_mode)) {
185			warnx("%s: is a directory", f);
186			eval = 1;
187			continue;
188		}
189		if (S_ISDIR(sb.st_mode))
190			rval = rmdir(f);
191		else {
192			rval = unlink(f);
193		}
194		if (rval && (errno != ENOENT)) {
195			warn("%s", f);
196			eval = 1;
197		}
198	}
199}
200
201static int
202check(char *path, char *name, struct stat *sp)
203{
204	int ch, first;
205	char modep[15];
206
207	/*
208	 * If it's not a symbolic link and it's unwritable and we're
209	 * talking to a terminal, ask.  Symbolic links are excluded
210	 * because their permissions are meaningless.  Check stdin_ok
211	 * first because we may not have stat'ed the file.
212	 */
213	if (!stdin_ok || S_ISLNK(sp->st_mode) || !access(name, W_OK) ||
214	    errno != EACCES)
215		return (1);
216	strmode(sp->st_mode, modep);
217	(void)fprintf(stderr, "override %s%s%s/%s for %s? ",
218	    modep + 1, modep[9] == ' ' ? "" : " ",
219	    user_from_uid(sp->st_uid, 0),
220	    group_from_gid(sp->st_gid, 0), path);
221	(void)fflush(stderr);
222
223	first = ch = getchar();
224	while (ch != '\n' && ch != EOF)
225		ch = getchar();
226	return (first == 'y' || first == 'Y');
227}
228
229/*
230 * POSIX.2 requires that if "." or ".." are specified as the basename
231 * portion of an operand, a diagnostic message be written to standard
232 * error and nothing more be done with such operands.
233 *
234 * Since POSIX.2 defines basename as the final portion of a path after
235 * trailing slashes have been removed, we'll remove them here.
236 */
237#define ISDOT(a)	((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
238static void
239checkdot(char **argv)
240{
241	char *p, **save, **t;
242	int complained;
243
244	complained = 0;
245	for (t = argv; *t;) {
246		/* strip trailing slashes */
247		p = strrchr (*t, '\0');
248		while (--p > *t && *p == '/')
249			*p = '\0';
250
251		/* extract basename */
252		if ((p = strrchr(*t, '/')) != NULL)
253			++p;
254		else
255			p = *t;
256
257		if (ISDOT(p)) {
258			if (!complained++)
259				warnx("\".\" and \"..\" may not be removed");
260			eval = 1;
261			for (save = t; (t[0] = t[1]) != NULL; ++t)
262				continue;
263			t = save;
264		} else
265			++t;
266	}
267}
268