xref: /netbsd-src/usr.bin/db/db.c (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
1 /*	$NetBSD: db.c,v 1.22 2008/10/07 10:03:47 lukem Exp $	*/
2 
3 /*-
4  * Copyright (c) 2002-2008 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Luke Mewburn of Wasabi Systems.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #if HAVE_NBTOOL_CONFIG_H
33 #include "nbtool_config.h"
34 #endif
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 #ifdef __RCSID
39 __RCSID("$NetBSD: db.c,v 1.22 2008/10/07 10:03:47 lukem Exp $");
40 #endif /* __RCSID */
41 #endif /* not lint */
42 
43 #include <ctype.h>
44 #include <db.h>
45 #include <err.h>
46 #include <fcntl.h>
47 #include <limits.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include <vis.h>
53 
54 
55 typedef enum {
56 	F_WRITE		= 1<<0,
57 	F_DELETE	= 1<<1,
58 	F_SHOW_KEY	= 1<<2,
59 	F_SHOW_VALUE	= 1<<3,
60 	F_QUIET		= 1<<10,
61 	F_IGNORECASE	= 1<<11,
62 	F_ENDIAN_BIG	= 1<<12,
63 	F_ENDIAN_LITTLE	= 1<<13,
64 	F_NO_NUL	= 1<<14,
65 	F_CREATENEW	= 1<<20,
66 	F_DUPLICATES	= 1<<21,
67 	F_REPLACE	= 1<<22,
68 	F_ENCODE_KEY	= 1<<23,
69 	F_ENCODE_VAL	= 1<<24,
70 	F_DECODE_KEY	= 1<<25,
71 	F_DECODE_VAL	= 1<<26,
72 } flags_t;
73 
74 int	main(int, char *[]);
75 void	db_print(DBT *, DBT *);
76 int	db_dump(void);
77 int	db_del(char *);
78 int	db_get(char *);
79 int	db_put(char *, char *);
80 int	parseline(FILE *, const char *, char **, char **);
81 int	encode_data(size_t, char *, char **);
82 int	decode_data(char *, char **);
83 void	parse_encode_decode_arg(const char *, int);
84 int	parse_encode_option(char **);
85 void	usage(void);
86 
87 flags_t	 	 flags = 0;
88 DB		*db;
89 const char	*outputsep = "\t";
90 int		 visflags = 0;
91 const char	*extra_echars = NULL;
92 
93 int
94 main(int argc, char *argv[])
95 {
96 	struct {
97 		char		*file;
98 		char		*type;
99 		DBTYPE	 	dbtype;
100 		void		*info;
101 		int	 	flags;
102 		mode_t	 	mode;
103 		unsigned int	pagesize;
104 	} oi;
105 	BTREEINFO	btreeinfo;
106 	HASHINFO	hashinfo;
107 	FILE		*infp;
108 	const char	*infile, *fieldsep;
109 	char		*p, *key, *val;
110 	int		ch, rv;
111 	long		lval;
112 
113 	setprogname(argv[0]);
114 
115 	infile = NULL;
116 	fieldsep = " ";
117 	infp = NULL;
118 	memset(&oi, 0, sizeof(oi));
119 	oi.mode = 0644;
120 	oi.pagesize = 4096;
121 
122 				/* parse arguments */
123 	while ( (ch = getopt(argc, argv,
124 			     "CDdE:F:f:iKm:NO:P:qRS:T:U:VwX:")) != -1) {
125 		switch (ch) {
126 
127 		case 'C':
128 			flags |= F_CREATENEW;
129 			break;
130 
131 		case 'D':
132 			flags |= F_DUPLICATES;
133 			break;
134 
135 		case 'd':
136 			flags |= F_DELETE;
137 			break;
138 
139 		case 'E':
140 			if (! optarg[0] || optarg[1])
141 				goto badendian;
142 			switch (toupper((int)optarg[0])) {
143 			case 'B':
144 				flags |= F_ENDIAN_BIG;
145 				break;
146 			case 'L':
147 				flags |= F_ENDIAN_LITTLE;
148 				break;
149 			case 'H':
150 				flags &= ~(F_ENDIAN_BIG | F_ENDIAN_LITTLE);
151 				break;
152 			default:
153  badendian:
154 				errx(1, "Bad endian `%s'", optarg);
155 			}
156 			break;
157 
158 		case 'F':
159 			if (! optarg[0])
160 				errx(1, "Invalid field separator `%s'",
161 				    optarg);
162 			fieldsep = optarg;
163 			break;
164 
165 		case 'f':
166 			infile = optarg;
167 			break;
168 
169 		case 'i':
170 			flags |= F_IGNORECASE;
171 			break;
172 
173 		case 'K':
174 			flags |= F_SHOW_KEY;
175 			break;
176 
177 		case 'm':
178 			lval = strtol(optarg, &p, 8);
179 			if (p == optarg || *p != '\0')
180 				errx(1, "Invalid octal number `%s'", optarg);
181 			if (lval < 0 || lval > 07777)
182 				errx(1, "Invalid mode `%s'", optarg);
183 			oi.mode = (mode_t)lval;
184 			break;
185 
186 		case 'N':
187 			flags |= F_NO_NUL;
188 			break;
189 
190 		case 'O':
191 			outputsep = optarg;
192 			break;
193 
194 		case 'P':
195 			lval = strtol(optarg, &p, 10);
196 			if (p == optarg || *p != '\0')
197 				errx(1, "Invalid pagesize `%s'", optarg);
198 			if (lval < 0 || lval >= UINT_MAX)
199 				errx(1, "Pagesize `%s' out of range", optarg);
200 			oi.pagesize = (unsigned int)lval;
201 			break;
202 
203 		case 'q':
204 			flags |= F_QUIET;
205 			break;
206 
207 		case 'R':
208 			flags |= F_REPLACE;
209 			break;
210 
211 		case 'S':
212 			parse_encode_decode_arg(optarg, 1 /* encode */);
213 			if (! (flags & (F_ENCODE_KEY | F_ENCODE_VAL)))
214 				errx(1, "Invalid encoding argument `%s'",
215 				    optarg);
216 			break;
217 
218 		case 'T':
219 			visflags = parse_encode_option(&optarg);
220 			if (! visflags)
221 				errx(1, "Invalid encoding/decoding option `%s'",
222 				    optarg);
223 			break;
224 
225 		case 'U':
226 			parse_encode_decode_arg(optarg, 0 /* decode */);
227 			if (! (flags & (F_DECODE_KEY | F_DECODE_VAL)))
228 				errx(1, "Invalid decoding argument `%s'",
229 				    optarg);
230 			break;
231 
232 		case 'V':
233 			flags |= F_SHOW_VALUE;
234 			break;
235 
236 		case 'w':
237 			flags |= F_WRITE;
238 			break;
239 
240 		case 'X':
241 			extra_echars = optarg;
242 			break;
243 
244 		default:
245 			usage();
246 
247 		}
248 	}
249 	argc -= optind;
250 	argv += optind;
251 
252 				/* validate arguments */
253 	if (argc < 2)
254 		usage();
255 	oi.type = argv[0];
256 	oi.file = argv[1];
257 	argc -= 2;
258 	argv += 2;
259 
260 	if (flags & F_WRITE) {
261 		if (flags & (F_SHOW_KEY | F_SHOW_VALUE | F_DELETE))
262 			usage();
263 		if ((!infile && argc < 2) || (argc % 2))
264 			usage();
265 		if (0 != (visflags & ~(VIS_HTTPSTYLE)))
266 			errx(1, "Unsupported decoding option provided to -T");
267 		oi.flags = O_RDWR | O_CREAT | O_EXLOCK;
268 		if (flags & F_CREATENEW)
269 			oi.flags |= O_TRUNC;
270 	} else if (flags & F_DELETE) {
271 		if (flags & (F_SHOW_KEY | F_SHOW_VALUE | F_WRITE))
272 			usage();
273 		if (!infile && argc < 1)
274 			usage();
275 		if (0 != (visflags & ~(VIS_HTTPSTYLE)))
276 			errx(1, "Unsupported decoding option provided to -T");
277 		oi.flags = O_RDWR | O_CREAT | O_EXLOCK;
278 	} else {
279 		if (! (flags & (F_SHOW_KEY | F_SHOW_VALUE)))
280 			flags |= (F_SHOW_KEY | F_SHOW_VALUE);
281 		oi.flags = O_RDONLY | O_SHLOCK;
282 	}
283 
284 				/* validate oi.type */
285 	if (strcmp(oi.type, "btree") == 0) {
286 		memset(&btreeinfo, 0, sizeof(btreeinfo));
287 		if (flags & F_ENDIAN_BIG)
288 			btreeinfo.lorder = 4321;
289 		else if (flags & F_ENDIAN_LITTLE)
290 			btreeinfo.lorder = 1234;
291 		if (flags & F_DUPLICATES)
292 			btreeinfo.flags = R_DUP;
293 		btreeinfo.psize = oi.pagesize;
294 		btreeinfo.cachesize = 1024 * 1024;
295 		oi.info = &btreeinfo;
296 		oi.dbtype = DB_BTREE;
297 	} else if (strcmp(oi.type, "hash") == 0) {
298 		memset(&hashinfo, 0, sizeof(hashinfo));
299 		if (flags & F_ENDIAN_BIG)
300 			hashinfo.lorder = 4321;
301 		else if (flags & F_ENDIAN_LITTLE)
302 			hashinfo.lorder = 1234;
303 		hashinfo.bsize = oi.pagesize;
304 		hashinfo.cachesize = 1024 * 1024;
305 		oi.info = &hashinfo;
306 		oi.dbtype = DB_HASH;
307 	} else {
308 		warnx("Unknown database type `%s'", oi.type);
309 		usage();
310 	}
311 
312 	if (infile) {
313 		if (strcmp(infile, "-") == 0)
314 			infp = stdin;
315 		else if ((infp = fopen(infile, "r")) == NULL)
316 			err(1, "Opening input file `%s'", infile);
317 	}
318 
319 				/* open database */
320 	db = dbopen(oi.file, oi.flags, oi.mode, oi.dbtype, oi.info);
321 	if (db == NULL)
322 		err(1, "Opening database `%s'", oi.file);
323 
324 
325 				/* manipulate database */
326 	rv = 0;
327 	if (flags & F_WRITE) {			/* write entries */
328 		for (ch = 0; ch < argc; ch += 2)
329 			if ((rv = db_put(argv[ch], argv[ch+1])))
330 				goto cleanup;
331 		if (infp) {
332 			while (parseline(infp, fieldsep, &key, &val)) {
333 				if ((rv = db_put(key, val)))
334 					goto cleanup;
335 			}
336 			if (ferror(infp)) {
337 				warnx("Reading `%s'", infile);
338 				goto cleanup;
339 			}
340 		}
341 	} else if (!infp && argc == 0) {	/* read all */
342 		db_dump();
343 	} else {				/* read/delete specific */
344 		int	(*dbop)(char *);
345 
346 		if (flags & F_DELETE)
347 			dbop = db_del;
348 		else
349 			dbop = db_get;
350 		for (ch = 0; ch < argc; ch++) {
351 			if ((rv = dbop(argv[ch])))
352 				goto cleanup;
353 		}
354 		if (infp) {
355 			while (parseline(infp, fieldsep, &key, NULL)) {
356 				if ((rv = dbop(key)))
357 					goto cleanup;
358 			}
359 			if (ferror(infp)) {
360 				warnx("Reading `%s'", infile);
361 				goto cleanup;
362 			}
363 		}
364 	}
365 
366 				/* close database */
367  cleanup:
368 	if (db->close(db) == -1)
369 		err(1, "Closing database `%s'", oi.file);
370 	if (infp)
371 		fclose(infp);
372 	return (rv);
373 }
374 
375 void
376 db_print(DBT *key, DBT *val)
377 {
378 	int	len;
379 	char	*data;
380 
381 #define	MINUSNUL(x)	((x) > 0  ?  (x) - (flags & F_NO_NUL ? 0 : 1)  :  0)
382 
383 	if (flags & F_SHOW_KEY) {
384 		if (flags & F_ENCODE_KEY) {
385 			len = encode_data(MINUSNUL(key->size),
386 			    (char *)key->data, &data);
387 		} else {
388 			len = (int)MINUSNUL(key->size);
389 			data = (char *)key->data;
390 		}
391 		printf("%.*s", len, data);
392 	}
393 	if ((flags & F_SHOW_KEY) && (flags & F_SHOW_VALUE))
394 		printf("%s", outputsep);
395 	if (flags & F_SHOW_VALUE) {
396 		if (flags & F_ENCODE_VAL) {
397 			len = encode_data(MINUSNUL(val->size),
398 			    (char *)val->data, &data);
399 		} else {
400 			len = (int)MINUSNUL(val->size);
401 			data = (char *)val->data;
402 		}
403 		printf("%.*s", len, data);
404 	}
405 	printf("\n");
406 }
407 
408 int
409 db_dump(void)
410 {
411 	DBT	key, val;
412 	int	rv;
413 
414 	while ((rv = db->seq(db, &key, &val, R_NEXT)) == 0)
415 		db_print(&key, &val);
416 	if (rv == -1)
417 		warn("Error dumping database");
418 	return (rv == 1 ? 0 : 1);
419 }
420 
421 static void
422 db_makekey(DBT *key, char *keystr, int downcase, int decode)
423 {
424 	char	*p, *ks;
425 	int	klen;
426 
427 	memset(key, 0, sizeof(*key));
428 	if (decode) {
429 		if ((klen = decode_data(keystr, &ks)) == -1)
430 			errx(1, "Invalid escape sequence in `%s'", keystr);
431 	} else {
432 		klen = strlen(keystr);
433 		ks = keystr;
434 	}
435 	key->data = ks;
436 	key->size = klen + (flags & F_NO_NUL ? 0 : 1);
437 	if (downcase && (flags & F_IGNORECASE)) {
438 		for (p = ks; *p; p++)
439 			if (isupper((int)*p))
440 				*p = tolower((int)*p);
441 	}
442 }
443 
444 int
445 db_del(char *keystr)
446 {
447 	DBT	key;
448 	int	r;
449 
450 	db_makekey(&key, keystr, 1, (flags & F_DECODE_KEY ? 1 : 0));
451 	r = db->del(db, &key, 0);
452 	switch (r) {
453 	case -1:
454 		if (! (flags & F_QUIET))
455 			warn("Error deleting key `%s'", keystr);
456 		r = 1;
457 		break;
458 	case 0:
459 		if (! (flags & F_QUIET))
460 			printf("Deleted key `%s'\n", keystr);
461 		break;
462 	case 1:
463 		if (! (flags & F_QUIET))
464 			warnx("Unknown key `%s'", keystr);
465 		break;
466 	default:
467 		abort();
468 	}
469 	if (flags & F_DECODE_KEY)
470 		free(key.data);
471 	return (r);
472 }
473 
474 int
475 db_get(char *keystr)
476 {
477 	DBT	key, val;
478 	char	*wantkey;
479 	int	r, found;
480 	u_int	seqflags;
481 
482 	db_makekey(&key, keystr, 1, (flags & F_DECODE_KEY ? 1 : 0));
483 	wantkey = strdup(key.data);
484 	if (wantkey == NULL)
485 		err(1, "Cannot allocate key buffer");
486 
487 	found = 0;
488 	seqflags = R_CURSOR;
489 	while ((r = db->seq(db, &key, &val, seqflags)) == 0) {
490 		if (strcmp((char *)key.data, wantkey) != 0) {
491 			r = 1;
492 			break;
493 		}
494 		seqflags = R_NEXT;
495 		found++;
496 		db_print(&key, &val);
497 		if (! (flags & F_DUPLICATES))
498 			break;
499 	}
500 
501 	switch (r) {
502 	case -1:
503 		warn("Error reading key `%s'", keystr);
504 		r = 1;
505 		break;
506 	case 0:
507 		break;
508 	case 1:
509 		if (found) {
510 			r = 0;
511 			break;
512 		}
513 		if (! (flags & F_QUIET)) {
514 			warnx("Unknown key `%s'", keystr);
515 		}
516 		break;
517 	default:
518 		abort();
519 	}
520 	if (flags & F_DECODE_KEY)
521 		free(key.data);
522 	free(wantkey);
523 	return (r);
524 }
525 
526 int
527 db_put(char *keystr, char *valstr)
528 {
529 	DBT	key, val;
530 	int	r = 0;
531 
532 	db_makekey(&key, keystr, 1, (flags & F_DECODE_KEY ? 1 : 0));
533 	db_makekey(&val, valstr, 0, (flags & F_DECODE_VAL ? 1 : 0));
534 	r = db->put(db, &key, &val, (flags & F_REPLACE) ? 0 : R_NOOVERWRITE);
535 	switch (r) {
536 	case -1:
537 		warn("Error writing key `%s'", keystr);
538 		r = 1;
539 		break;
540 	case 0:
541 		if (! (flags & F_QUIET))
542 			printf("Added key `%s'\n", keystr);
543 		break;
544 	case 1:
545 		if (! (flags & F_QUIET))
546 			warnx("Key `%s' already exists", keystr);
547 		break;
548 	default:
549 		abort();
550 	}
551 	if (flags & F_DECODE_KEY)
552 		free(key.data);
553 	if (flags & F_DECODE_VAL)
554 		free(val.data);
555 	return (r);
556 }
557 
558 int
559 parseline(FILE *fp, const char *sep, char **kp, char **vp)
560 {
561 	size_t	len;
562 	char	*key, *val;
563 
564 	key = fgetln(fp, &len);
565 	if (key == NULL)		/* end of file, or error */
566 		return (0);
567 
568 	if (key[len-1] == '\n')		/* check for \n at EOL */
569 		key[--len] = '\0';
570 	else
571 		return (0);
572 
573 	*kp = key;
574 	if (vp == NULL)			/* don't split if don't want value */
575 		return (1);
576 	if ((val = strstr(key, sep)) == NULL)
577 		val = key + len;
578 	else {
579 		*val = '\0';
580 		val += strlen(sep);
581 	}
582 	*vp = val;
583 	return (1);
584 }
585 
586 int
587 encode_data(size_t len, char *data, char **edata)
588 {
589 	static char	*buf = NULL;
590 	char		*nbuf;
591 	static size_t	buflen = 0;
592 	size_t		elen;
593 
594 	elen = 1 + (len * 4);
595 	if (elen > buflen) {
596 		if ((nbuf = realloc(buf, elen)) == NULL)
597 			err(1, "Cannot allocate encoding buffer");
598 		buf = nbuf;
599 		buflen = elen;
600 	}
601 	*edata = buf;
602 	if (extra_echars) {
603 		return (strsvisx(buf, data, len, visflags, extra_echars));
604 	} else {
605 		return (strvisx(buf, data, len, visflags));
606 	}
607 }
608 
609 int
610 decode_data(char *data, char **ddata)
611 {
612 	char	*buf;
613 
614 	if ((buf = malloc(strlen(data) + 1)) == NULL)
615 		err(1, "Cannot allocate decoding buffer");
616 	*ddata = buf;
617 	return (strunvisx(buf, data, (visflags & VIS_HTTPSTYLE)));
618 }
619 
620 void
621 parse_encode_decode_arg(const char *arg, int encode)
622 {
623 	if (! arg[0] || arg[1])
624 		return;
625 	if (arg[0] == 'k' || arg[0] == 'b') {
626 		if (encode)
627 			flags |= F_ENCODE_KEY;
628 		else
629 			flags |= F_DECODE_KEY;
630 	}
631 	if (arg[0] == 'v' || arg[0] == 'b') {
632 		if (encode)
633 			flags |= F_ENCODE_VAL;
634 		else
635 			flags |= F_DECODE_VAL;
636 	}
637 	return;
638 }
639 
640 int
641 parse_encode_option(char **arg)
642 {
643 	int	r = 0;
644 	int	encmask = ~(VIS_CSTYLE | VIS_HTTPSTYLE | VIS_OCTAL);
645 
646 	for(; **arg; (*arg)++) {
647 		switch (**arg) {
648 			case 'b':
649 				r |= VIS_NOSLASH;
650 				break;
651 			case 'c':
652 				r &= encmask;
653 				r |= VIS_CSTYLE;
654 				break;
655 			case 'h':
656 				r &= encmask;
657 				r |= VIS_HTTPSTYLE;
658 				break;
659 			case 'o':
660 				r &= encmask;
661 				r |= VIS_OCTAL;
662 				break;
663 			case 's':
664 				r |= VIS_SAFE;
665 				break;
666 			case 't':
667 				r |= VIS_TAB;
668 				break;
669 			case 'w':
670 				r |= VIS_WHITE;
671 				break;
672 			default:
673 				return (0);
674 				break;
675 		}
676 	}
677 	return (r);
678 }
679 
680 void
681 usage(void)
682 {
683 	const char *p = getprogname();
684 
685 	fprintf(stderr,
686 "usage: %s    [-KiNqV] [-E endian] [-f infile] [-O outsep] [-S visitem]\n"
687 "             [-T visspec] [-X extravis] type dbfile [key [...]]\n"
688 "       %s -d [-iNq] [-E endian] [-f infile] [-T visspec] [-U unvisitem]\n"
689 "             type dbfile [key [...]]\n"
690 "       %s -w [-CDiNqR] [-E endian] [-F isep] [-f infile] [-m mode]\n"
691 "             [-P pagesize] [-T visspec] [-U unvisitem]\n"
692 "             type dbfile [key value [...]]\n"
693 	    ,p ,p ,p );
694 	fprintf(stderr,
695 "Supported modes:\n"
696 "                read keys  [default]\n"
697 "   -d           delete keys\n"
698 "   -w           write (add) keys/values\n"
699 "Supported options:\n"
700 "   -C           create empty (truncated) database\n"
701 "   -D           allow duplicates\n"
702 "   -E endian    database endian: `B'ig, `L'ittle, `H'ost  [default: H]\n"
703 "   -F isep      input field separator string  [default: a space]\n"
704 "   -f infile    file of keys (read|delete) or keys/vals (write)\n"
705 "   -i           ignore case of key by converting to lower case\n"
706 "   -K           print key\n"
707 "   -m mode      mode of created database  [default: 0644]\n"
708 "   -N           don't NUL terminate key\n"
709 "   -O outsep    output field separator string  [default: a tab]\n"
710 "   -P pagesize  database page size  [default: 4096]\n"
711 "   -q           quiet operation (missing keys aren't errors)\n"
712 "   -R           replace existing keys\n"
713 "   -S visitem   items to strvis(3) encode: 'k'ey, 'v'alue, 'b'oth\n"
714 "   -T visspec   options to control -S and -U; like vis(1) options\n"
715 "   -U unvisitem items to strunvis(3) decode: 'k'ey, 'v'alue, 'b'oth\n"
716 "   -V           print value\n"
717 "   -X extravis  extra characters to encode with -S\n"
718 	    );
719 	exit(1);
720 }
721