xref: /openbsd/bin/mv/rm.c (revision 264ca280)
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 
51 extern char *__progname;
52 
53 static int eval, stdin_ok;
54 
55 static int	check(char *, char *, struct stat *);
56 static void	checkdot(char **);
57 static void	rm_file(char **);
58 static void	rm_tree(char **);
59 
60 static void __dead
61 usage(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  */
74 int
75 rmmain(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 
89 static void
90 rm_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 
163 static void
164 rm_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 
201 static int
202 check(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])))
238 static void
239 checkdot(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