xref: /dragonfly/sbin/hammer/cmd_snapshot.c (revision e0b1d537)
1 /*
2  * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
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
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * $DragonFly: src/sbin/hammer/cmd_snapshot.c,v 1.7 2008/07/10 18:47:22 mneumann Exp $
35  */
36 
37 #include "hammer.h"
38 #include <sys/param.h>
39 #include <sys/mount.h>
40 #include <sys/types.h>
41 #include <sys/stat.h>
42 #include <unistd.h>
43 #include <string.h>
44 #include <time.h>
45 
46 extern char *find_pfs_mount(int pfsid, uuid_t parentuuid, int ismaster);
47 
48 #define DEFAULT_SNAPSHOT_NAME "snap-%Y%m%d-%H%M"
49 
50 static void snapshot_usage(int exit_code);
51 static void snapshot_add(int fd, const char *fsym, const char *tsym,
52 		const char *label, hammer_tid_t tid);
53 static void snapshot_ls(const char *path);
54 static void snapshot_del(int fsfd, hammer_tid_t tid);
55 static char *dirpart(const char *path);
56 
57 /*
58  * hammer snap <path> [<note>]
59  *
60  * Path may be a directory, softlink, or non-existent (a softlink will be
61  * created).
62  */
63 void
64 hammer_cmd_snap(char **av, int ac, int tostdout, int fsbase)
65 {
66 	struct hammer_ioc_synctid synctid;
67 	struct hammer_ioc_version version;
68 	char *dirpath;
69 	char *fsym;
70 	char *tsym;
71 	struct stat st;
72 	char note[64];
73 	int fsfd;
74 
75 	if (ac == 0 || ac > 2) {
76 		snapshot_usage(1);
77 		/* not reached */
78 		exit(1);
79 	}
80 
81 	if (ac == 2)
82 		snprintf(note, sizeof(note), "%s", av[1]);
83 	else
84 		note[0] = 0;
85 
86 	/*
87 	 * Figure out the softlink path and directory path
88 	 */
89 	if (stat(av[0], &st) < 0) {
90 		dirpath = dirpart(av[0]);
91 		tsym = av[0];
92 	} else if (S_ISLNK(st.st_mode)) {
93 		dirpath = dirpart(av[0]);
94 		tsym = av[0];
95 	} else if (S_ISDIR(st.st_mode)) {
96 		time_t t = time(NULL);
97 		struct tm *tp;
98 		char extbuf[64];
99 
100 		tp = localtime(&t);
101 		strftime(extbuf, sizeof(extbuf), DEFAULT_SNAPSHOT_NAME, tp);
102 
103 		dirpath = strdup(av[0]);
104 		asprintf(&tsym, "%s/%s", dirpath, extbuf);
105 	} else {
106 		err(2, "hammer snap: File %s exists and is not a softlink\n",
107 		    av[0]);
108 		/* not reached */
109 	}
110 
111 	/*
112 	 * Get a handle on some directory in the filesystem for the
113 	 * ioctl (so it is stored in the correct PFS).
114 	 */
115 	fsfd = open(dirpath, O_RDONLY);
116 	if (fsfd < 0) {
117 		err(2, "hammer snap: Cannot open directory %s\n", dirpath);
118 		/* not reached */
119 	}
120 
121 	/*
122 	 * Must be at least version 3 to use this command.
123 	 */
124         bzero(&version, sizeof(version));
125 
126         if (ioctl(fsfd, HAMMERIOC_GET_VERSION, &version) < 0) {
127 		err(2, "Unable to create snapshot");
128 		/* not reached */
129 	} else if (version.cur_version < 3) {
130 		errx(2, "Unable to create snapshot: This directive requires "
131 			"you to upgrade\n"
132 			"the filesystem to version 3.  "
133 			"Use 'hammer snapshot' for legacy operation.");
134 		/* not reached */
135 	}
136 
137 	/*
138 	 * Synctid to get a transaction id for the snapshot.
139 	 */
140 	bzero(&synctid, sizeof(synctid));
141 	synctid.op = HAMMER_SYNCTID_SYNC2;
142 	if (ioctl(fsfd, HAMMERIOC_SYNCTID, &synctid) < 0) {
143 		err(2, "hammer snap: Synctid %s failed",
144 		    dirpath);
145 	}
146 	if (tostdout) {
147 		if (strcmp(dirpath, ".") == 0 || strcmp(dirpath, "..") == 0) {
148 			printf("%s/@@0x%016jx\n",
149 				dirpath, (uintmax_t)synctid.tid);
150 		} else {
151 			printf("%s@@0x%016jx\n",
152 				dirpath, (uintmax_t)synctid.tid);
153 		}
154 		fsym = NULL;
155 		tsym = NULL;
156 	}
157 
158 	/*
159 	 * Contents of the symlink being created.
160 	 */
161 	if (fsbase) {
162 		struct statfs buf;
163 
164 		if (statfs(dirpath, &buf) < 0) {
165 			err(2, "hammer snap: Cannot determine mount for %s",
166 			    dirpath);
167 		}
168 		asprintf(&fsym, "%s/@@0x%016jx",
169 			 buf.f_mntonname, (uintmax_t)synctid.tid);
170 	} else if (strcmp(dirpath, ".") == 0 || strcmp(dirpath, "..") == 0) {
171 		asprintf(&fsym, "%s/@@0x%016jx",
172 			 dirpath, (uintmax_t)synctid.tid);
173 	} else {
174 		asprintf(&fsym, "%s@@0x%016jx",
175 			 dirpath, (uintmax_t)synctid.tid);
176 	}
177 
178 	/*
179 	 * Create the snapshot.
180 	 */
181 	snapshot_add(fsfd, fsym, tsym, note, synctid.tid);
182 	free(dirpath);
183 }
184 
185 /*
186  * hammer snapls [<path> ...]
187  *
188  * If no arguments are specified snapshots for the PFS containing the
189  * current directory are listed.
190  */
191 void
192 hammer_cmd_snapls(char **av, int ac)
193 {
194 	int i;
195 
196 	for (i = 0; i < ac; ++i)
197 		snapshot_ls(av[i]);
198 	if (ac == 0)
199 		snapshot_ls(".");
200 }
201 
202 /*
203  * hammer snaprm <path> ...
204  * hammer snaprm <transid> ...
205  * hammer snaprm <filesystem> <transid> ...
206  */
207 void
208 hammer_cmd_snaprm(char **av, int ac)
209 {
210 	struct stat st;
211 	char linkbuf[1024];
212 	intmax_t tid;
213 	int fsfd = -1;
214 	int i;
215 	int delete;
216 	enum snaprm_mode { none_m, path_m, tid_m } mode = none_m;
217 	char *dirpath;
218 	char *ptr, *ptr2;
219 
220 	if (ac == 0) {
221 		snapshot_usage(1);
222 		/* not reached */
223 	}
224 
225 	for (i = 0; i < ac; ++i) {
226 		if (lstat(av[i], &st) < 0) {
227 			tid = strtoull(av[i], &ptr, 16);
228 			if (*ptr) {
229 				err(2, "hammer snaprm: not a file or tid: %s",
230 				    av[i]);
231 				/* not reached */
232 			}
233 			if (mode == path_m) {
234 				snapshot_usage(1);
235 				/* not reached */
236 			}
237 			mode = tid_m;
238 			if (fsfd < 0)
239 				fsfd = open(".", O_RDONLY);
240 			snapshot_del(fsfd, tid);
241 		} else if (S_ISDIR(st.st_mode)) {
242 			if (i != 0 || ac < 2) {
243 				snapshot_usage(1);
244 				/* not reached */
245 			}
246 			if (fsfd >= 0)
247 				close(fsfd);
248 			fsfd = open(av[i], O_RDONLY);
249 			if (fsfd < 0) {
250 				err(2, "hammer snaprm: cannot open dir %s",
251 				    av[i]);
252 				/* not reached */
253 			}
254 			mode = tid_m;
255 		} else if (S_ISLNK(st.st_mode)) {
256 			dirpath = dirpart(av[i]);
257 			bzero(linkbuf, sizeof(linkbuf));
258 			if (readlink(av[i], linkbuf, sizeof(linkbuf) - 1) < 0) {
259 				err(2, "hammer snaprm: cannot read softlink: "
260 				       "%s", av[i]);
261 				/* not reached */
262 			}
263 			if (linkbuf[0] == '/') {
264 				free(dirpath);
265 				dirpath = dirpart(linkbuf);
266 			} else {
267 				asprintf(&ptr, "%s/%s", dirpath, linkbuf);
268 				free(dirpath);
269 				dirpath = dirpart(ptr);
270 			}
271 
272 			if (fsfd >= 0)
273 				close(fsfd);
274 			fsfd = open(dirpath, O_RDONLY);
275 			if (fsfd < 0) {
276 				err(2, "hammer snaprm: cannot open dir %s",
277 				    dirpath);
278 				/* not reached */
279 			}
280 
281 			delete = 1;
282 			if (i == 0 && ac > 1) {
283 				mode = path_m;
284 				if (lstat(av[1], &st) < 0) {
285 					tid = strtoull(av[1], &ptr, 16);
286 					if (*ptr == '\0') {
287 						delete = 0;
288 						mode = tid_m;
289 					}
290 				}
291 			} else {
292 				if (mode == tid_m) {
293 					snapshot_usage(1);
294 					/* not reached */
295 				}
296 				mode = path_m;
297 			}
298 			if (delete && (ptr = strrchr(linkbuf, '@')) &&
299 			    ptr > linkbuf && ptr[-1] == '@' && ptr[1]) {
300 				tid = strtoull(ptr + 1, &ptr2, 16);
301 				if (*ptr2 == '\0') {
302 					snapshot_del(fsfd, tid);
303 					remove(av[i]);
304 				}
305 			}
306 			free(dirpath);
307 		} else {
308 			err(2, "hammer snaprm: not directory or snapshot "
309 			       "softlink: %s", av[i]);
310 			/* not reached */
311 		}
312 	}
313 	if (fsfd >= 0)
314 		close(fsfd);
315 }
316 
317 /*
318  * snapshot <softlink-dir>
319  * snapshot <filesystem> <softlink-dir> [<note>]
320  */
321 void
322 hammer_cmd_snapshot(char **av, int ac)
323 {
324 	const char *filesystem;
325 	const char *softlink_dir;
326 	char *softlink_fmt;
327 	struct statfs buf;
328 	struct stat st;
329 	struct hammer_ioc_synctid synctid;
330 	char *from;
331 	char *to;
332 	char *note = NULL;
333 
334 	if (ac == 1) {
335 		filesystem = NULL;
336 		softlink_dir = av[0];
337 	} else if (ac == 2) {
338 		filesystem = av[0];
339 		softlink_dir = av[1];
340 	} else if (ac == 3) {
341 		filesystem = av[0];
342 		softlink_dir = av[1];
343 		note = av[2];
344 	} else {
345 		snapshot_usage(1);
346 		/* not reached */
347 		softlink_dir = NULL;
348 		filesystem = NULL;
349 	}
350 
351 	if (stat(softlink_dir, &st) == 0) {
352 		if (!S_ISDIR(st.st_mode))
353 			err(2, "File %s already exists", softlink_dir);
354 
355 		if (filesystem == NULL) {
356 			if (statfs(softlink_dir, &buf) != 0) {
357 				err(2, "Unable to determine filesystem of %s",
358 				    softlink_dir);
359 			}
360 			filesystem = buf.f_mntonname;
361 		}
362 
363 		softlink_fmt = malloc(strlen(softlink_dir) + 1 + 1 +
364 		                      sizeof(DEFAULT_SNAPSHOT_NAME));
365 		if (softlink_fmt == NULL)
366 			err(2, "Failed to allocate string");
367 
368 		strcpy(softlink_fmt, softlink_dir);
369 		if (softlink_fmt[strlen(softlink_fmt)-1] != '/')
370 			strcat(softlink_fmt, "/");
371 		strcat(softlink_fmt, DEFAULT_SNAPSHOT_NAME);
372 	} else {
373 		softlink_fmt = strdup(softlink_dir);
374 
375 		if (filesystem == NULL) {
376 			/*
377 			 * strip-off last '/path' segment to get the softlink
378 			 * directory, which we need to determine the filesystem
379 			 * we are on.
380 			 */
381 			char *pos = strrchr(softlink_fmt, '/');
382 			if (pos != NULL)
383 				*pos = '\0';
384 
385 			if (stat(softlink_fmt, &st) != 0 ||
386 			    !S_ISDIR(st.st_mode)) {
387 				err(2, "Unable to determine softlink dir %s",
388 				    softlink_fmt);
389 			}
390 			if (statfs(softlink_fmt, &buf) != 0) {
391 				err(2, "Unable to determine filesystem of %s",
392 				    softlink_fmt);
393 			}
394 			filesystem = buf.f_mntonname;
395 
396 			/* restore '/' */
397 			if (pos != NULL)
398 				*pos = '/';
399 		}
400 	}
401 
402 	/*
403 	 * Synctid
404 	 */
405 	bzero(&synctid, sizeof(synctid));
406 	synctid.op = HAMMER_SYNCTID_SYNC2;
407 
408 	int fd = open(filesystem, O_RDONLY);
409 	if (fd < 0)
410 		err(2, "Unable to open %s", filesystem);
411 	if (ioctl(fd, HAMMERIOC_SYNCTID, &synctid) < 0)
412 		err(2, "Synctid %s failed", filesystem);
413 
414 	asprintf(&from, "%s/@@0x%016jx", filesystem, (uintmax_t)synctid.tid);
415 	if (from == NULL)
416 		err(2, "Couldn't generate string");
417 
418 	int sz = strlen(softlink_fmt) + 50;
419 	to = malloc(sz);
420 	if (to == NULL)
421 		err(2, "Failed to allocate string");
422 
423 	time_t t = time(NULL);
424 	if (strftime(to, sz, softlink_fmt, localtime(&t)) == 0)
425 		err(2, "String buffer too small");
426 
427 	asprintf(&from, "%s/@@0x%016jx", filesystem, (uintmax_t)synctid.tid);
428 
429 	snapshot_add(fd, from, to, note, synctid.tid);
430 
431 	close(fd);
432 	printf("%s\n", to);
433 
434 	free(softlink_fmt);
435 	free(from);
436 	free(to);
437 }
438 
439 static
440 void
441 snapshot_add(int fd, const char *fsym, const char *tsym, const char *label,
442 	     hammer_tid_t tid)
443 {
444 	struct hammer_ioc_version version;
445 	struct hammer_ioc_snapshot snapshot;
446 
447         bzero(&version, sizeof(version));
448         bzero(&snapshot, sizeof(snapshot));
449 
450 	/*
451 	 * For HAMMER filesystem v3+ the snapshot is recorded in meta-data.
452 	 */
453         if (ioctl(fd, HAMMERIOC_GET_VERSION, &version) == 0 &&
454 	    version.cur_version >= 3) {
455 		snapshot.index = 0;
456 		snapshot.count = 1;
457 		snapshot.snaps[0].tid = tid;
458 		snapshot.snaps[0].ts = time(NULL) * 1000000ULL;
459 		if (label) {
460 			snprintf(snapshot.snaps[0].label,
461 				 sizeof(snapshot.snaps[0].label),
462 				 "%s",
463 				 label);
464 		}
465 		if (ioctl(fd, HAMMERIOC_ADD_SNAPSHOT, &snapshot) < 0) {
466 			err(2, "Unable to create snapshot");
467 		} else if (snapshot.head.error &&
468 			   snapshot.head.error != EEXIST) {
469 			errx(2, "Unable to create snapshot: %s\n",
470 				strerror(snapshot.head.error));
471 		}
472         }
473 
474 	/*
475 	 * Create a symlink for the snapshot.  If a file exists with the same
476 	 * name the new symlink will replace it.
477 	 */
478 	if (fsym && tsym) {
479 		remove(tsym);
480 		if (symlink(fsym, tsym) < 0) {
481 			err(2, "Unable to create symlink %s", tsym);
482 		}
483 	}
484 }
485 
486 static
487 void
488 snapshot_ls(const char *path)
489 {
490 	/*struct hammer_ioc_version version;*/
491 	struct hammer_ioc_info info;
492 	struct hammer_ioc_snapshot snapshot;
493 	struct hammer_ioc_pseudofs_rw pfs;
494 	struct hammer_pseudofs_data pfs_od;
495 	struct hammer_snapshot_data *snap;
496 	struct tm *tp;
497 	time_t t;
498 	u_int32_t i;
499 	int fd, ismaster;
500 	char snapts[64];
501 	char *mntpoint;
502 
503 	fd = open(path, O_RDONLY);
504 	if (fd < 0) {
505 		err(2, "hammer snapls: cannot open %s", path);
506 		/* not reached */
507 	}
508 
509 	bzero(&pfs, sizeof(pfs));
510 	bzero(&pfs_od, sizeof(pfs_od));
511 	pfs.pfs_id = -1;
512 	pfs.ondisk = &pfs_od;
513 	pfs.bytes = sizeof(struct hammer_pseudofs_data);
514 	if (ioctl(fd, HAMMERIOC_GET_PSEUDOFS, &pfs) < 0) {
515 		err(2, "hammer snapls: cannot retrieve PFS info on %s", path);
516 		/* not reached */
517 	}
518 
519 	bzero(&info, sizeof(info));
520 	if ((ioctl(fd, HAMMERIOC_GET_INFO, &info)) < 0) {
521                 err(2, "hammer snapls: cannot retrieve HAMMER info");
522 		/* not reached */
523         }
524 
525 	ismaster = (pfs_od.mirror_flags & HAMMER_PFSD_SLAVE) ? 0 : 1;
526 	mntpoint = libhammer_find_pfs_mount(pfs.pfs_id, info.vol_fsid, ismaster);
527 
528 	/* Note the degenerate case of PFS #0 */
529 	printf("Snapshots on %s\tPFS #%d\n",
530 	    pfs.pfs_id == 0 ? path : mntpoint, pfs.pfs_id);
531 	printf("Transaction ID\t\tTimestamp\t\tNote\n");
532 
533 	if (mntpoint)
534 		free(mntpoint);
535 
536 	bzero(&snapshot, sizeof(snapshot));
537 	do {
538 		if (ioctl(fd, HAMMERIOC_GET_SNAPSHOT, &snapshot) < 0) {
539 			err(2, "hammer snapls: %s: not HAMMER fs or "
540 				"version < 3", path);
541 			/* not reached */
542 		}
543 		for (i = 0; i < snapshot.count; ++i) {
544 			snap = &snapshot.snaps[i];
545 
546 			t = snap->ts / 1000000ULL;
547 			tp = localtime(&t);
548 			strftime(snapts, sizeof(snapts),
549 				 "%Y-%m-%d %H:%M:%S %Z", tp);
550 			printf("0x%016jx\t%s\t%s\n",
551 				(uintmax_t)snap->tid, snapts,
552 				strlen(snap->label) ? snap->label : "-");
553 		}
554 	} while (snapshot.head.error == 0 && snapshot.count);
555 }
556 
557 static
558 void
559 snapshot_del(int fsfd, hammer_tid_t tid)
560 {
561 	struct hammer_ioc_snapshot snapshot;
562 	struct hammer_ioc_version version;
563 
564         bzero(&version, sizeof(version));
565 
566         if (ioctl(fsfd, HAMMERIOC_GET_VERSION, &version) < 0) {
567 		err(2, "hammer snaprm 0x%016jx", (uintmax_t)tid);
568 	}
569 	if (version.cur_version < 3) {
570 		errx(2, "hammer snaprm 0x%016jx: You must upgrade to version "
571 			" 3 to use this directive", (uintmax_t)tid);
572 	}
573 
574 	bzero(&snapshot, sizeof(snapshot));
575 	snapshot.count = 1;
576 	snapshot.snaps[0].tid = tid;
577 
578 	/*
579 	 * Do not abort if we are unable to remove the meta-data.
580 	 */
581 	if (ioctl(fsfd, HAMMERIOC_DEL_SNAPSHOT, &snapshot) < 0) {
582 		err(2, "hammer snaprm 0x%016jx",
583 		      (uintmax_t)tid);
584 	} else if (snapshot.head.error == ENOENT) {
585 		fprintf(stderr, "Warning: hammer snaprm 0x%016jx: "
586 				"meta-data not found\n",
587 			(uintmax_t)tid);
588 	} else if (snapshot.head.error) {
589 		fprintf(stderr, "Warning: hammer snaprm 0x%016jx: %s\n",
590 			(uintmax_t)tid, strerror(snapshot.head.error));
591 	}
592 }
593 
594 static
595 void
596 snapshot_usage(int exit_code)
597 {
598 	fprintf(stderr,
599     "hammer snap <path> [<note>]\t\tcreate snapshot & link, points to\n"
600 				"\t\t\t\t\tbase of PFS mount\n"
601     "hammer snaplo <path> [<note>]\t\tcreate snapshot & link, points to\n"
602 				"\t\t\t\t\ttarget dir\n"
603     "hammer snapq <dir> [<note>]\t\tcreate snapshot, output path to stdout\n"
604     "hammer snaprm <path> ...\t\tdelete snapshots; filesystem is CWD\n"
605     "hammer snaprm <transid> ...\t\tdelete snapshots\n"
606     "hammer snaprm <filesystem> <transid> ...\tdelete snapshots\n"
607     "hammer snapls [<path> ...]\t\tlist available snapshots\n"
608     "\n"
609     "NOTE: Snapshots are created in filesystem meta-data, any directory\n"
610     "      in a HAMMER filesystem or PFS may be specified.  If the path\n"
611     "      specified does not exist this function will also create a\n"
612     "      softlink.\n"
613     "\n"
614     "      When deleting snapshots transaction ids may be directly specified\n"
615     "      or file paths to snapshot softlinks may be specified.  If a\n"
616     "      softlink is specified the softlink will also be deleted.\n"
617     "\n"
618     "NOTE: The old 'hammer snapshot [<filesystem>] <snapshot-dir>' form\n"
619     "      is still accepted but is a deprecated form.  This form will\n"
620     "      work for older hammer versions.  The new forms only work for\n"
621     "      HAMMER version 3 or later filesystems.  HAMMER can be upgraded\n"
622     "      to version 3 in-place.\n"
623 	);
624 	exit(exit_code);
625 }
626 
627 static
628 char *
629 dirpart(const char *path)
630 {
631 	const char *ptr;
632 	char *res;
633 
634 	ptr = strrchr(path, '/');
635 	if (ptr) {
636 		while (ptr > path && ptr[-1] == '/')
637 			--ptr;
638 		if (ptr == path)
639 			ptr = NULL;
640 	}
641 	if (ptr == NULL) {
642 		path = ".";
643 		ptr = path + 1;
644 	}
645 	res = malloc(ptr - path + 1);
646 	bcopy(path, res, ptr - path);
647 	res[ptr - path] = 0;
648 	return(res);
649 }
650