xref: /dragonfly/bin/mv/mv.c (revision 0ca59c34)
1 /*-
2  * Copyright (c) 1989, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Ken Smith of The State University of New York at Buffalo.
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/param.h>
34 #include <sys/time.h>
35 #include <sys/wait.h>
36 #include <sys/stat.h>
37 #include <sys/mount.h>
38 
39 #include <err.h>
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <grp.h>
43 #include <limits.h>
44 #include <paths.h>
45 #include <pwd.h>
46 #include <signal.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <sysexits.h>
51 #include <unistd.h>
52 
53 /* Exit code for a failed exec. */
54 #define EXEC_FAILED 127
55 
56 #ifndef _PATH_RM
57 #define	_PATH_RM	"/bin/rm"
58 #endif
59 
60 static int	fflg, hflg, iflg, nflg, vflg;
61 static volatile sig_atomic_t info;
62 
63 static int	copy(const char *, const char *);
64 static int	do_move(const char *, const char *);
65 static int	fastcopy(const char *, const char *, struct stat *);
66 static void	usage(void);
67 static void	siginfo(int);
68 
69 int
70 main(int argc, char *argv[])
71 {
72 	size_t baselen, len;
73 	int rval;
74 	char *p, *endp;
75 	struct stat sb;
76 	int ch;
77 	char path[PATH_MAX];
78 
79 	while ((ch = getopt(argc, argv, "fhinv")) != -1)
80 		switch (ch) {
81 		case 'h':
82 			hflg = 1;
83 			break;
84 		case 'i':
85 			iflg = 1;
86 			fflg = nflg = 0;
87 			break;
88 		case 'f':
89 			fflg = 1;
90 			iflg = nflg = 0;
91 			break;
92 		case 'n':
93 			nflg = 1;
94 			fflg = iflg = 0;
95 			break;
96 		case 'v':
97 			vflg = 1;
98 			break;
99 		default:
100 			usage();
101 		}
102 	argc -= optind;
103 	argv += optind;
104 
105 	signal(SIGINFO, siginfo);
106 
107 	if (argc < 2)
108 		usage();
109 
110 	/*
111 	 * If the stat on the target fails or the target isn't a directory,
112 	 * try the move.  More than 2 arguments is an error in this case.
113 	 */
114 	if (stat(argv[argc - 1], &sb) || !S_ISDIR(sb.st_mode)) {
115 		if (argc > 2)
116 			usage();
117 		exit(do_move(argv[0], argv[1]));
118 	}
119 
120 	/*
121 	 * If -h was specified, treat the target as a symlink instead of
122 	 * directory.
123 	 */
124 	if (hflg) {
125 		if (argc > 2)
126 			usage();
127 		if (lstat(argv[1], &sb) == 0 && S_ISLNK(sb.st_mode))
128 			exit(do_move(argv[0], argv[1]));
129 	}
130 
131 	/* It's a directory, move each file into it. */
132 	if (strlen(argv[argc - 1]) > sizeof(path) - 1)
133 		errx(1, "%s: destination pathname too long", *argv);
134 	strcpy(path, argv[argc - 1]);
135 	baselen = strlen(path);
136 	endp = &path[baselen];
137 	if (!baselen || *(endp - 1) != '/') {
138 		*endp++ = '/';
139 		++baselen;
140 	}
141 	for (rval = 0; --argc; ++argv) {
142 		/*
143 		 * Find the last component of the source pathname.  It
144 		 * may have trailing slashes.
145 		 */
146 		p = *argv + strlen(*argv);
147 		while (p != *argv && p[-1] == '/')
148 			--p;
149 		while (p != *argv && p[-1] != '/')
150 			--p;
151 
152 		if ((baselen + (len = strlen(p))) >= PATH_MAX) {
153 			warnx("%s: destination pathname too long", *argv);
154 			rval = 1;
155 		} else {
156 			memmove(endp, p, (size_t)len + 1);
157 			if (do_move(*argv, path))
158 				rval = 1;
159 		}
160 	}
161 	exit(rval);
162 }
163 
164 static int
165 do_move(const char *from, const char *to)
166 {
167 	struct stat sb;
168 	int ask, ch, first;
169 	char modep[15];
170 
171 	/*
172 	 * Check access.  If interactive and file exists, ask user if it
173 	 * should be replaced.  Otherwise if file exists but isn't writable
174 	 * make sure the user wants to clobber it.
175 	 */
176 	if (!fflg && !access(to, F_OK)) {
177 
178 		/* prompt only if source exist */
179 		if (lstat(from, &sb) == -1) {
180 			warn("%s", from);
181 			return (1);
182 		}
183 
184 #define YESNO "(y/n [n]) "
185 		ask = 0;
186 		if (nflg) {
187 			if (vflg)
188 				printf("%s not overwritten\n", to);
189 			return (0);
190 		} else if (iflg) {
191 			fprintf(stderr, "overwrite %s? %s", to, YESNO);
192 			ask = 1;
193 		} else if (access(to, W_OK) && !stat(to, &sb) && isatty(STDIN_FILENO)) {
194 			strmode(sb.st_mode, modep);
195 			fprintf(stderr, "override %s%s%s/%s for %s? %s",
196 			    modep + 1, modep[9] == ' ' ? "" : " ",
197 			    user_from_uid((unsigned long)sb.st_uid, 0),
198 			    group_from_gid((unsigned long)sb.st_gid, 0), to, YESNO);
199 			ask = 1;
200 		}
201 		if (ask) {
202 			first = ch = getchar();
203 			while (ch != '\n' && ch != EOF)
204 				ch = getchar();
205 			if (first != 'y' && first != 'Y') {
206 				fprintf(stderr, "not overwritten\n");
207 				return (0);
208 			}
209 		}
210 	}
211 	/*
212 	 * Rename on FreeBSD will fail with EISDIR and ENOTDIR, before failing
213 	 * with EXDEV.  Therefore, copy() doesn't have to perform the checks
214 	 * specified in the Step 3 of the POSIX mv specification.
215 	 */
216 	if (!rename(from, to)) {
217 		if (vflg)
218 			printf("%s -> %s\n", from, to);
219 		return (0);
220 	}
221 
222 	if (errno == EXDEV) {
223 		struct statfs sfs;
224 		char path[PATH_MAX];
225 		int target_is_file = 0;
226 
227 		if (!lstat(to, &sb) && S_ISREG(sb.st_mode))
228 			target_is_file = 1;
229 		/*
230 		 * If the source is a symbolic link and is on another
231 		 * filesystem, it can be recreated at the destination.
232 		 */
233 		if (lstat(from, &sb) == -1) {
234 			warn("%s", from);
235 			return (1);
236 		}
237 		/* Can't mv(1) directory into a file ever. */
238 		if (target_is_file && S_ISDIR(sb.st_mode)) {
239 			warn("cannot overwrite %s with directory", to);
240 			return (1);
241 		}
242 		if (!S_ISLNK(sb.st_mode)) {
243 			/* Can't mv(1) a mount point. */
244 			if (realpath(from, path) == NULL) {
245 				warn("cannot resolve %s: %s", from, path);
246 				return (1);
247 			}
248 			if (!statfs(path, &sfs) &&
249 			    !strcmp(path, sfs.f_mntonname)) {
250 				warnx("cannot rename a mount point");
251 				return (1);
252 			}
253 		}
254 	} else {
255 		warn("rename %s to %s", from, to);
256 		return (1);
257 	}
258 
259 	/*
260 	 * If rename fails because we're trying to cross devices, and
261 	 * it's a regular file, do the copy internally; otherwise, use
262 	 * cp and rm.
263 	 */
264 	if (lstat(from, &sb)) {
265 		warn("%s", from);
266 		return (1);
267 	}
268 	return (S_ISREG(sb.st_mode) ?
269 	    fastcopy(from, to, &sb) : copy(from, to));
270 }
271 
272 static int
273 fastcopy(const char *from, const char *to, struct stat *sbp)
274 {
275 	struct timeval tval[2];
276 	static u_int blen = MAXPHYS;
277 	static char *bp = NULL;
278 	mode_t oldmode;
279 	int from_fd, to_fd;
280 	ssize_t nread;
281 
282 	if ((from_fd = open(from, O_RDONLY, 0)) < 0) {
283 		warn("fastcopy: open() failed (from): %s", from);
284 		return (1);
285 	}
286 	if (bp == NULL && (bp = malloc((size_t)blen)) == NULL) {
287 		warnx("malloc(%u) failed", blen);
288 		return (1);
289 	}
290 	while ((to_fd =
291 	    open(to, O_CREAT | O_EXCL | O_TRUNC | O_WRONLY, 0)) < 0) {
292 		if (errno == EEXIST && unlink(to) == 0)
293 			continue;
294 		warn("fastcopy: open() failed (to): %s", to);
295 		close(from_fd);
296 		return (1);
297 	}
298 	while ((nread = read(from_fd, bp, (size_t)blen)) > 0)
299 		if (write(to_fd, bp, (size_t)nread) != nread) {
300 			warn("fastcopy: write() failed: %s", to);
301 			goto err;
302 		}
303 	if (nread < 0) {
304 		warn("fastcopy: read() failed: %s", from);
305 err:		if (unlink(to))
306 			warn("%s: remove", to);
307 		close(from_fd);
308 		close(to_fd);
309 		return (1);
310 	}
311 
312 	oldmode = sbp->st_mode & ALLPERMS;
313 	if (fchown(to_fd, sbp->st_uid, sbp->st_gid)) {
314 		warn("%s: set owner/group (was: %lu/%lu)", to,
315 		    (u_long)sbp->st_uid, (u_long)sbp->st_gid);
316 		if (oldmode & (S_ISUID | S_ISGID)) {
317 			warnx(
318 "%s: owner/group changed; clearing suid/sgid (mode was 0%03o)",
319 			    to, oldmode);
320 			sbp->st_mode &= ~(S_ISUID | S_ISGID);
321 		}
322 	}
323 	if (fchmod(to_fd, sbp->st_mode))
324 		warn("%s: set mode (was: 0%03o)", to, oldmode);
325 
326 	close(from_fd);
327 	/*
328 	 * XXX
329 	 * NFS doesn't support chflags; ignore errors unless there's reason
330 	 * to believe we're losing bits.  (Note, this still won't be right
331 	 * if the server supports flags and we were trying to *remove* flags
332 	 * on a file that we copied, i.e., that we didn't create.)
333 	 */
334 	errno = 0;
335 	if (fchflags(to_fd, (u_long)sbp->st_flags))
336 		if (errno != EOPNOTSUPP || sbp->st_flags != 0)
337 			warn("%s: set flags (was: 0%07o)", to, sbp->st_flags);
338 
339 	tval[0].tv_sec = sbp->st_atime;
340 	tval[1].tv_sec = sbp->st_mtime;
341 	tval[0].tv_usec = tval[1].tv_usec = 0;
342 	if (utimes(to, tval))
343 		warn("%s: set times", to);
344 
345 	if (close(to_fd)) {
346 		warn("%s", to);
347 		return (1);
348 	}
349 
350 	if (unlink(from)) {
351 		warn("%s: remove", from);
352 		return (1);
353 	}
354 	if (vflg)
355 		printf("%s -> %s\n", from, to);
356 	return (0);
357 }
358 
359 static int
360 copy(const char *from, const char *to)
361 {
362 	struct stat sb;
363 	int status;
364 	pid_t pid;
365 
366 	if (lstat(to, &sb) == 0) {
367 		/* Destination path exists. */
368 		if (S_ISDIR(sb.st_mode)) {
369 			if (rmdir(to) != 0) {
370 				warn("rmdir %s", to);
371 				return (1);
372 			}
373 		} else {
374 			if (unlink(to) != 0) {
375 				warn("unlink %s", to);
376 				return (1);
377 			}
378 		}
379 	} else if (errno != ENOENT) {
380 		warn("%s", to);
381 		return (1);
382 	}
383 
384 	/* Copy source to destination. */
385 	if (!(pid = vfork())) {
386 		execl(_PATH_CP, "mv", vflg ? "-PRpv" : "-PRp", "--", from, to,
387 		    NULL);
388 		_exit(EXEC_FAILED);
389 	}
390 	if (waitpid(pid, &status, 0) == -1) {
391 		warn("%s %s %s: waitpid", _PATH_CP, from, to);
392 		return (1);
393 	}
394 	if (!WIFEXITED(status)) {
395 		warnx("%s %s %s: did not terminate normally",
396 		    _PATH_CP, from, to);
397 		return (1);
398 	}
399 	switch (WEXITSTATUS(status)) {
400 	case 0:
401 		break;
402 	case EXEC_FAILED:
403 		warnx("%s %s %s: exec failed", _PATH_CP, from, to);
404 		return (1);
405 	default:
406 		warnx("%s %s %s: terminated with %d (non-zero) status",
407 		    _PATH_CP, from, to, WEXITSTATUS(status));
408 		return (1);
409 	}
410 
411 	/* Delete the source. */
412 	if (!(pid = vfork())) {
413 		execl(_PATH_RM, "mv", "-rf", "--", from, NULL);
414 		_exit(EXEC_FAILED);
415 	}
416 	if (waitpid(pid, &status, 0) == -1) {
417 		warn("%s %s: waitpid", _PATH_RM, from);
418 		return (1);
419 	}
420 	if (!WIFEXITED(status)) {
421 		warnx("%s %s: did not terminate normally", _PATH_RM, from);
422 		return (1);
423 	}
424 	switch (WEXITSTATUS(status)) {
425 	case 0:
426 		break;
427 	case EXEC_FAILED:
428 		warnx("%s %s: exec failed", _PATH_RM, from);
429 		return (1);
430 	default:
431 		warnx("%s %s: terminated with %d (non-zero) status",
432 		    _PATH_RM, from, WEXITSTATUS(status));
433 		return (1);
434 	}
435 	return (0);
436 }
437 
438 static void
439 usage(void)
440 {
441 
442 	fprintf(stderr, "%s\n%s\n",
443 		"usage: mv [-f | -i | -n] [-hv] source target",
444 		"       mv [-f | -i | -n] [-v] source ... directory");
445 	exit(EX_USAGE);
446 }
447 
448 static void
449 siginfo(int notused __unused)
450 {
451 	info = 1;
452 }
453