File: mt.c

package info (click to toggle)
mt-st 1.1-4
  • links: PTS
  • area: main
  • in suites: squeeze, wheezy
  • size: 228 kB
  • ctags: 350
  • sloc: ansic: 1,849; sh: 119; makefile: 88
file content (788 lines) | stat: -rw-r--r-- 22,966 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
/*	This file contains the source of the 'mt' program intended for
	Linux systems. The program supports the basic mt commands found
	in most Unix-like systems. In addition to this the program
	supports several commands designed for use with the Linux SCSI
	tape drive.

	Maintained by Kai M�kisara (email Kai.Makisara@kolumbus.fi)
	Copyright by Kai M�kisara, 1998 - 2008. The program may be distributed
	according to the GNU Public License

	Last Modified: Sun Apr 27 19:49:00 2008 by kai.makisara
*/

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/utsname.h>

#include "mtio.h"

#ifndef DEFTAPE
#define DEFTAPE "/dev/tape"     /* default tape device */
#endif /* DEFTAPE */

#define VERSION "1.1"

typedef int (* cmdfunc)(/* int, struct cmdef_tr *, int, char ** */);

typedef struct cmdef_tr {
    char *cmd_name;
    int cmd_code;
    cmdfunc cmd_function;
    int cmd_count_bits;
    unsigned char cmd_fdtype;
    unsigned char arg_cnt;
    int error_tests;
} cmdef_tr;

#define NO_FD      0
#define FD_RDONLY  1
#define FD_RDWR    2

#define NO_ARGS       0
#define ONE_ARG       1
#define TWO_ARGS      2
#define MULTIPLE_ARGS 255

#define DO_BOOLEANS    1002
#define SET_BOOLEANS   1003
#define CLEAR_BOOLEANS 1004

#define ET_ONLINE    1
#define ET_WPROT     2

static void usage(int);
static int do_standard(int, cmdef_tr *, int, char **);
static int do_drvbuffer(int, cmdef_tr *, int, char **);
static int do_options(int, cmdef_tr *, int, char **);
static int do_tell(int, cmdef_tr *, int, char **);
static int do_partseek(int, cmdef_tr *, int, char **);
static int do_status(int, cmdef_tr *, int, char **);
static int print_densities(int, cmdef_tr *, int, char **);
static int do_asf(int, cmdef_tr *, int, char **);
static int do_show_options(int, cmdef_tr *, int, char **);
static void test_error(int, cmdef_tr *);

static cmdef_tr cmds[] = {
    { "weof",		MTWEOF,	  do_standard, 0, FD_RDWR,   ONE_ARG,
    ET_ONLINE | ET_WPROT },
    { "wset",		MTWSM,	  do_standard, 0, FD_RDWR,   ONE_ARG,
    ET_ONLINE | ET_WPROT },
    { "eof",		MTWEOF,	  do_standard, 0, FD_RDWR, ONE_ARG,
    ET_ONLINE },
    { "fsf",		MTFSF,	  do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "fsfm",		MTFSFM,	  do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "bsf",		MTBSF,	  do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "bsfm",		MTBSFM,	  do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "fsr",		MTFSR,	  do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "bsr",		MTBSR,	  do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "fss",		MTFSS,	  do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "bss",		MTBSS,	  do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "rewind",		MTREW,	  do_standard, 0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "offline",	MTOFFL,	  do_standard, 0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "rewoffl",	MTOFFL,	  do_standard, 0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "eject",		MTOFFL,	  do_standard, 0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "retension",	MTRETEN,  do_standard, 0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "eod",		MTEOM,	  do_standard, 0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "seod",		MTEOM,	  do_standard, 0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "seek",		MTSEEK,   do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "tell",		MTTELL,	  do_tell,     0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "status",		MTNOP,	  do_status,   0, FD_RDONLY, NO_ARGS,
    0 },
    { "erase",		MTERASE,  do_standard, 0, FD_RDWR,   ONE_ARG,
    ET_ONLINE },
    { "setblk",		MTSETBLK, do_standard, 0, FD_RDONLY, ONE_ARG,
    0 },
    { "lock",		MTLOCK,   do_standard, 0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "unlock", 	MTUNLOCK, do_standard, 0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "load",		MTLOAD,	  do_standard, 0, FD_RDONLY, ONE_ARG,
    0 },
    { "compression",	MTCOMPRESSION,  do_standard,  0, FD_RDONLY, ONE_ARG,
    0 },
    { "setdensity",	MTSETDENSITY,   do_standard,  0, FD_RDONLY, ONE_ARG,
    0 },
    { "drvbuffer",	MTSETDRVBUFFER, do_drvbuffer, 0, FD_RDONLY, ONE_ARG,
    0 },
    { "stwrthreshold",	MTSETDRVBUFFER, do_drvbuffer, MT_ST_WRITE_THRESHOLD,
      FD_RDONLY, ONE_ARG, 0},
    { "stoptions",	DO_BOOLEANS,    do_options,   0, FD_RDONLY,
      MULTIPLE_ARGS, 0},
    { "stsetoptions",   SET_BOOLEANS,   do_options,   0, FD_RDONLY,
      MULTIPLE_ARGS, 0},
    { "stclearoptions", CLEAR_BOOLEANS, do_options,   0, FD_RDONLY,
      MULTIPLE_ARGS, 0},
    { "defblksize",	MTSETDRVBUFFER, do_drvbuffer, MT_ST_DEF_BLKSIZE,
      FD_RDONLY, ONE_ARG, 0},
    { "defdensity",	MTSETDRVBUFFER, do_drvbuffer, MT_ST_DEF_DENSITY,
      FD_RDONLY, ONE_ARG, 0},
    { "defdrvbuffer",	MTSETDRVBUFFER, do_drvbuffer, MT_ST_DEF_DRVBUFFER,
      FD_RDONLY, ONE_ARG, 0},
    { "defcompression", MTSETDRVBUFFER, do_drvbuffer, MT_ST_DEF_COMPRESSION,
      FD_RDONLY, ONE_ARG, 0},
    { "stsetcln",	MTSETDRVBUFFER, do_drvbuffer, MT_ST_SET_CLN,
      FD_RDONLY, ONE_ARG, 0},
    { "sttimeout",	MTSETDRVBUFFER, do_drvbuffer, MT_ST_SET_TIMEOUT,
      FD_RDONLY, ONE_ARG, 0},
    { "stlongtimeout",	MTSETDRVBUFFER, do_drvbuffer, MT_ST_SET_LONG_TIMEOUT,
      FD_RDONLY, ONE_ARG, 0},
    { "densities",	0, print_densities,     0, NO_FD,     NO_ARGS,
    0 },
    { "setpartition",	MTSETPART, do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "mkpartition",	MTMKPART,  do_standard, 0, FD_RDWR,   ONE_ARG,
    ET_ONLINE },
    { "partseek",	0,         do_partseek, 0, FD_RDONLY, TWO_ARGS,
    ET_ONLINE },
    { "asf",		0,         do_asf, MTREW,  FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "stshowopt",	0,         do_show_options, 0,  FD_RDONLY, ONE_ARG,
    0 },
    { NULL, 0, 0, 0 }
};


static struct densities {
    int code;
    char *name;
} density_tbl[] = {
    {0x00, "default"},
    {0x01, "NRZI (800 bpi)"},
    {0x02, "PE (1600 bpi)"},
    {0x03, "GCR (6250 bpi)"},
    {0x04, "QIC-11"},
    {0x05, "QIC-45/60 (GCR, 8000 bpi)"},
    {0x06, "PE (3200 bpi)"},
    {0x07, "IMFM (6400 bpi)"},
    {0x08, "GCR (8000 bpi)"},
    {0x09, "GCR (37871 bpi)"},
    {0x0a, "MFM (6667 bpi)"},
    {0x0b, "PE (1600 bpi)"},
    {0x0c, "GCR (12960 bpi)"},
    {0x0d, "GCR (25380 bpi)"},
    {0x0f, "QIC-120 (GCR 10000 bpi)"},
    {0x10, "QIC-150/250 (GCR 10000 bpi)"},
    {0x11, "QIC-320/525 (GCR 16000 bpi)"},
    {0x12, "QIC-1350 (RLL 51667 bpi)"},
    {0x13, "DDS (61000 bpi)"},
    {0x14, "EXB-8200 (RLL 43245 bpi)"},
    {0x15, "EXB-8500 or QIC-1000"},
    {0x16, "MFM 10000 bpi"},
    {0x17, "MFM 42500 bpi"},
    {0x18, "TZ86"},
    {0x19, "DLT 10GB"},
    {0x1a, "DLT 20GB"},
    {0x1b, "DLT 35GB"},
    {0x1c, "QIC-385M"},
    {0x1d, "QIC-410M"},
    {0x1e, "QIC-1000C"},
    {0x1f, "QIC-2100C"},
    {0x20, "QIC-6GB"},
    {0x21, "QIC-20GB"},
    {0x22, "QIC-2GB"},
    {0x23, "QIC-875"},
    {0x24, "DDS-2"},
    {0x25, "DDS-3"},
    {0x26, "DDS-4 or QIC-4GB"},
    {0x27, "Exabyte Mammoth"},
    {0x28, "Exabyte Mammoth-2"},
    {0x29, "QIC-3080MC"},
    {0x30, "AIT-1 or MLR3"},
    {0x31, "AIT-2"},
    {0x32, "AIT-3 or SLR7"},
    {0x33, "SLR6"},
    {0x34, "SLR100"},
    {0x40, "DLT1 40 GB, or Ultrium"},
    {0x41, "DLT 40GB, or Ultrium2"},
    {0x42, "LTO-2"},
    {0x44, "LTO-3"},
    {0x45, "QIC-3095-MC (TR-4)"},
    {0x46, "LTO-4"},
    {0x47, "DDS-5 or TR-5"},
    {0x51, "IBM 3592 J1A"},
    {0x52, "IBM 3592 E05"},
    {0x80, "DLT 15GB uncomp. or Ecrix"},
    {0x81, "DLT 15GB compressed"},
    {0x82, "DLT 20GB uncompressed"},
    {0x83, "DLT 20GB compressed"},
    {0x84, "DLT 35GB uncompressed"},
    {0x85, "DLT 35GB compressed"},
    {0x86, "DLT1 40 GB uncompressed"},
    {0x87, "DLT1 40 GB compressed"},
    {0x88, "DLT 40GB uncompressed"},
    {0x89, "DLT 40GB compressed"},
    {0x8c, "EXB-8505 compressed"},
    {0x90, "SDLT110 uncompr/EXB-8205 compr"},
    {0x91, "SDLT110 compressed"},
    {0x92, "SDLT160 uncompressed"},
    {0x93, "SDLT160 comprssed"}
};

#define NBR_DENSITIES (sizeof(density_tbl) / sizeof(struct densities))

static struct booleans {
    char *name;
    unsigned long bitmask;
    char *expl;
} boolean_tbl[] = {
    {"buffer-writes", MT_ST_BUFFER_WRITES, "buffered writes"},
    {"async-writes",  MT_ST_ASYNC_WRITES,  "asynchronous writes"},
    {"read-ahead",    MT_ST_READ_AHEAD,    "read-ahead for fixed block size"},
    {"debug",         MT_ST_DEBUGGING,     "debugging (if compiled into driver)"},
    {"two-fms",       MT_ST_TWO_FM,        "write two filemarks when file closed"},
    {"fast-eod",      MT_ST_FAST_MTEOM, "space directly to eod (and lose file number)"},
    {"auto-lock",     MT_ST_AUTO_LOCK,     "automatically lock/unlock drive door"},
    {"def-writes",    MT_ST_DEF_WRITES,    "the block size and density are for writes"},
    {"can-bsr",       MT_ST_CAN_BSR,       "drive can space backwards well"},
    {"no-blklimits",  MT_ST_NO_BLKLIMS,    "drive doesn't support read block limits"},
    {"can-partitions",MT_ST_CAN_PARTITIONS,"drive can handle partitioned tapes"},
    {"scsi2logical",  MT_ST_SCSI2LOGICAL,  "logical block addresses used with SCSI-2"},
    {"no-wait",       MT_ST_NOWAIT,        "immediate mode for rewind, etc."},
#ifdef MT_ST_SYSV
    {"sysv",	      MT_ST_SYSV,	   "enable the SystemV semantics"},
#endif
    {"sili",	      MT_ST_SILI,	   "enable SILI for variable block mode"},
    {"cleaning",      MT_ST_SET_CLN,	   "set the cleaning bit location and mask"},
    {NULL, 0}};

static char *tape_name;   /* The tape name for messages */


	int
main(int argc, char **argv)
{
    int mtfd, cmd_code, i, argn, len, oflags;
    char *cmdstr;
    cmdef_tr *comp, *comp2;

    for (argn=1; argn < argc; argn++)
	if (*argv[argn] == '-')
	    switch (*(argv[argn] + 1)) {
	    case 'f':
	    case 't':
		argn += 1;
		if (argn >= argc) {
		    usage(0);
		    exit(1);
		}
		tape_name = argv[argn];
		break;
	    case 'h':
		usage(1);
		exit(0);
		break;
	    case 'v':
		printf("mt-st v. %s\n", VERSION);
		exit(0);
		break;
	    case '-':
		if (*(argv[argn] + 1) == '-' &&
		    *(argv[argn] + 2) == 'v') {
		    printf("mt-st v. %s\n", VERSION);
		    exit(0);
		}
		/* Fall through */
	    default:
		usage(0);
		exit(1);
	}
	else
	    break;

    if (tape_name == NULL && (tape_name = getenv("TAPE")) == NULL)
	tape_name = DEFTAPE;
       
    if (argn >= argc ) {
	usage(0);
	exit(1);
    }
    cmdstr = argv[argn++];

    len = strlen(cmdstr);
    for (comp = cmds; comp->cmd_name != NULL; comp++)
	if (strncmp(cmdstr, comp->cmd_name, len) == 0)
	    break;
    if (comp->cmd_name == NULL) {
	fprintf(stderr, "mt: unknown command \"%s\"\n", cmdstr);
	usage(1);
	exit(1);
    }
    if (len != strlen(comp->cmd_name)) {
	for (comp2 = comp + 1; comp2->cmd_name != NULL; comp2++)
	    if (strncmp(cmdstr, comp2->cmd_name, len) == 0)
		break;
	if (comp2->cmd_name != NULL) {
	    fprintf(stderr, "mt: ambiguous command \"%s\"\n", cmdstr);
	    usage(1);
	    exit(1);
	}
    }
    if (comp->arg_cnt != MULTIPLE_ARGS && comp->arg_cnt < argc - argn) {
	fprintf(stderr, "mt: too many arguments for the command '%s'.\n",
		comp->cmd_name);
	exit(1);
    }
    cmd_code = comp->cmd_code;

    if (comp->cmd_fdtype != NO_FD) {
	oflags = comp->cmd_fdtype == FD_RDONLY ? O_RDONLY : O_RDWR;
	if ((comp->error_tests & ET_ONLINE) == 0)
	    oflags |= O_NONBLOCK;
	if ((mtfd = open(tape_name, oflags)) < 0) {
	    perror(tape_name);
	    exit(1);
	}
    }
    else
	mtfd = (-1);

    if (comp->cmd_function != NULL) {
	i = comp->cmd_function(mtfd, comp, argc - argn,
			       (argc - argn > 0 ? argv + argn : NULL));
	if (i) {
	    if (errno == ENOSYS)
		fprintf(stderr, "mt: Command not supported by this kernel.\n");
	    else if (comp->error_tests != 0)
		test_error(mtfd, comp);
	}
    }
    else {
	fprintf(stderr, "mt: Internal error: command without function.\n");
	i = 1;
    }

    if (mtfd >= 0)
	close(mtfd);
    return i;
}


	static void
usage(int explain)
{
    int ind;
    char line[100];

    fprintf(stderr, "usage: mt [-v] [--version] [-h] [ -f device ] command [ count ]\n");
    if (explain) {
	for (ind=0; cmds[ind].cmd_name != NULL; ) {
	    if (ind == 0)
		strcpy(line, "commands: ");
	    else
		strcpy(line, "          ");
	    for ( ; cmds[ind].cmd_name != NULL; ind++) {
		strcat(line, cmds[ind].cmd_name);
		if (cmds[ind+1].cmd_name != NULL)
		    strcat(line, ", ");
		else
		    strcat(line, ".");
		if (strlen(line) >= 70 || cmds[ind+1].cmd_name == NULL) {
		    fprintf(stderr, "%s\n", line);
		    ind++;
		    break;
		}
	    }
	}
    }
}



/* Do a command that simply feeds an argument to the MTIOCTOP ioctl */
	static int
do_standard(int mtfd, cmdef_tr *cmd, int argc, char **argv)
{
    struct mtop mt_com;
    char *endp;

    mt_com.mt_op = cmd->cmd_code;
    mt_com.mt_count = (argc > 0 ? strtol(*argv, &endp, 0) : 1);
    if (argc > 0 && endp != *argv) {
	if (*endp == 'k')
	    mt_com.mt_count *= 1024;
	else if (*endp == 'M')
	    mt_com.mt_count *= 1024 * 1024;
	else if (*endp == 'G')
	    mt_com.mt_count *= 1024 * 1024 * 1024;
    }
    mt_com.mt_count |= cmd->cmd_count_bits;
    if (mt_com.mt_count < 0) {
	fprintf(stderr, "mt: negative repeat count\n");
	return 1;
    }
    if (ioctl(mtfd, MTIOCTOP, (char *)&mt_com) < 0) {
	perror(tape_name);
	return 2;
    }
    return 0;
}


/* The the drive buffering and other things with this (highly overloaded)
   ioctl function. (See also do_options below.) */
	static int
do_drvbuffer(int mtfd, cmdef_tr *cmd, int argc, char **argv)
{
    struct mtop mt_com;

    mt_com.mt_op = MTSETDRVBUFFER;
    mt_com.mt_count = (argc > 0 ? strtol(*argv, NULL, 0) : 1);
    if ((cmd->cmd_count_bits & MT_ST_OPTIONS) == MT_ST_DEF_OPTIONS)
	mt_com.mt_count &= 0xfffff;
#ifdef MT_ST_TIMEOUTS
    else if ((cmd->cmd_count_bits & MT_ST_OPTIONS) == MT_ST_TIMEOUTS)
	mt_com.mt_count &= 0x7ffffff;
#endif
    else
	mt_com.mt_count &= 0xfffffff;
    mt_com.mt_count |= cmd->cmd_count_bits;
    if (ioctl(mtfd, MTIOCTOP, (char *)&mt_com) < 0) {
	perror(tape_name);
	return 2;
    }
    return 0;
}


/* Set the tape driver options */
	static int
do_options(int mtfd, cmdef_tr *cmd, int argc, char **argv)
{
    int i, an, len;
    struct mtop mt_com;

    mt_com.mt_op = MTSETDRVBUFFER;
    if (argc == 0)
	mt_com.mt_count = 0;
    else if (isdigit(**argv))
	mt_com.mt_count = strtol(*argv, NULL, 0) & ~MT_ST_OPTIONS;
    else
	for (an = 0, mt_com.mt_count = 0; an < argc; an++) {
	    len = strlen(argv[an]);
	    for (i=0; boolean_tbl[i].name != NULL; i++)
		if (!strncmp(boolean_tbl[i].name, argv[an], len)) {
		    mt_com.mt_count |= boolean_tbl[i].bitmask;
		    break;
		}
	    if (boolean_tbl[i].name == NULL) {
		fprintf(stderr, "Illegal property name '%s'.\n", argv[an]);
		fprintf(stderr, "The implemented property names are:\n");
		for (i=0; boolean_tbl[i].name != NULL; i++)
		    fprintf(stderr, "  %9s -> %s\n", boolean_tbl[i].name,
			    boolean_tbl[i].expl);
		return 1;
	    }
	    if (len != strlen(boolean_tbl[i].name))
		for (i++ ; boolean_tbl[i].name != NULL; i++)
		    if (!strncmp(boolean_tbl[i].name, argv[an], len)) {
			fprintf(stderr, "Property name '%s' ambiguous.\n",
				argv[an]);
			return 1;
		    }
	}

    switch (cmd->cmd_code) {
    case DO_BOOLEANS:
	mt_com.mt_count |= MT_ST_BOOLEANS;
	break;
    case SET_BOOLEANS:
	mt_com.mt_count |= MT_ST_SETBOOLEANS;
	break;
    case CLEAR_BOOLEANS:
	mt_com.mt_count |= MT_ST_CLEARBOOLEANS;
	break;
    }
    if (ioctl(mtfd, MTIOCTOP, (char *)&mt_com) < 0) {
	perror(tape_name);
	return 2;
    }
    return 0;
}


/* Tell where the tape is */
	static int
do_tell(int mtfd, cmdef_tr *cmd, int argc, char **argv)
{
    struct mtpos mt_pos;

    if (ioctl(mtfd, MTIOCPOS, (char *)&mt_pos) < 0) {
	perror(tape_name);
	return 2;
    }
    printf("At block %ld.\n", mt_pos.mt_blkno);
    return 0;
}


/* Position the tape to a specific location within a specified partition */
	static int
do_partseek(int mtfd, cmdef_tr *cmd, int argc, char **argv)
{
    struct mtop mt_com;

    mt_com.mt_op = MTSETPART;
    mt_com.mt_count = (argc > 0 ? strtol(*argv, NULL, 0) : 0);
    if (ioctl(mtfd, MTIOCTOP, (char *)&mt_com) < 0) {
	perror(tape_name);
	return 2;
    }
    mt_com.mt_op = MTSEEK;
    mt_com.mt_count = (argc > 1 ? strtol(argv[1], NULL, 0) : 0);
    if (ioctl(mtfd, MTIOCTOP, (char *)&mt_com) < 0) {
	perror(tape_name);
	return 2;
    }
    return 0;
}


/* Position to start of file n. This might be implemented more intelligently
   some day. */
	static int
do_asf(int mtfd, cmdef_tr *cmd, int argc, char **argv)
{
    struct mtop mt_com;

    mt_com.mt_op = MTREW;
    mt_com.mt_count = 1;
    if (ioctl(mtfd, MTIOCTOP, (char *)&mt_com) < 0) {
	perror(tape_name);
	return 2;
    }
    mt_com.mt_count = (argc > 0 ? strtol(*argv, NULL, 0) : 0);
    if (mt_com.mt_count > 0) {
	mt_com.mt_op = MTFSF;
	if (ioctl(mtfd, MTIOCTOP, (char *)&mt_com) < 0) {
	    perror(tape_name);
	    return 2;
	}
    }
    return 0;
}


/*** Decipher the status ***/

	static int
do_status(int mtfd, cmdef_tr *cmd, int argc, char **argv)
{
    struct mtget status;
    int dens, i;
    char *type, *density;

    if (ioctl(mtfd, MTIOCGET, (char *)&status) < 0) {
	perror(tape_name);
	return 2;
    }

    if (status.mt_type == MT_ISSCSI1)
	type = "SCSI 1";
    else if (status.mt_type == MT_ISSCSI2)
	type = "SCSI 2";
    else if (status.mt_type == MT_ISONSTREAM_SC)
	type = "OnStream SC-, DI-, DP-, or USB";
    else
	type = NULL;
    if (type == NULL) {
	if (status.mt_type & 0x800000)
	    printf ("qic-117 drive type = 0x%05lx\n", status.mt_type & 0x1ffff);
	else if (status.mt_type == 0)
	    printf("IDE-Tape (type code 0) ?\n");
	else
	    printf("Unknown tape drive type (type code %ld)\n", status.mt_type);
	printf("File number=%d, block number=%d.\n",
	       status.mt_fileno, status.mt_blkno);
	printf("mt_resid: %ld, mt_erreg: 0x%lx\n",
	       status.mt_resid, status.mt_erreg);
	printf("mt_dsreg: 0x%lx, mt_gstat: 0x%lx\n",
	       status.mt_dsreg, status.mt_gstat);
    }
    else {
	printf("%s tape drive:\n", type);
	if (status.mt_type == MT_ISSCSI2)
	    printf("File number=%d, block number=%d, partition=%ld.\n",
		   status.mt_fileno, status.mt_blkno, (status.mt_resid & 0xff));
	else
	    printf("File number=%d, block number=%d.\n",
		   status.mt_fileno, status.mt_blkno);
	if (status.mt_type == MT_ISSCSI1 ||
	    status.mt_type == MT_ISSCSI2 ||
	    status.mt_type == MT_ISONSTREAM_SC) {
	    dens = (status.mt_dsreg & MT_ST_DENSITY_MASK) >> MT_ST_DENSITY_SHIFT;
	    density = "no translation";
	    for (i=0; i < NBR_DENSITIES; i++)
		if (density_tbl[i].code == dens) {
		    density = density_tbl[i].name;
		    break;
		}
	    printf("Tape block size %ld bytes. Density code 0x%x (%s).\n",
		   ((status.mt_dsreg & MT_ST_BLKSIZE_MASK) >> MT_ST_BLKSIZE_SHIFT),
		   dens, density);

	    printf("Soft error count since last status=%ld\n",
		   (status.mt_erreg & MT_ST_SOFTERR_MASK) >> MT_ST_SOFTERR_SHIFT);
	}
    }

    printf("General status bits on (%lx):\n", status.mt_gstat);
    if (GMT_EOF(status.mt_gstat))
	printf(" EOF");
    if (GMT_BOT(status.mt_gstat))
	printf(" BOT");
    if (GMT_EOT(status.mt_gstat))
	printf(" EOT");
    if (GMT_SM(status.mt_gstat))
	printf(" SM");
    if (GMT_EOD(status.mt_gstat))
	printf(" EOD");
    if (GMT_WR_PROT(status.mt_gstat))
	printf(" WR_PROT");
    if (GMT_ONLINE(status.mt_gstat))
	printf(" ONLINE");
    if (GMT_D_6250(status.mt_gstat))
	printf(" D_6250");
    if (GMT_D_1600(status.mt_gstat))
	printf(" D_1600");
    if (GMT_D_800(status.mt_gstat))
	printf(" D_800");
    if (GMT_DR_OPEN(status.mt_gstat))
	printf(" DR_OPEN");	  
    if (GMT_IM_REP_EN(status.mt_gstat))
	printf(" IM_REP_EN");
    if (GMT_CLN(status.mt_gstat))
	printf(" CLN");
    printf("\n");
    return 0;
}


/* From linux/drivers/scsi/st.[ch] */
#define ST_NBR_MODE_BITS 2
#define ST_NBR_MODES (1 << ST_NBR_MODE_BITS)
#define ST_MODE_SHIFT (7 - ST_NBR_MODE_BITS)
#define ST_MODE_MASK ((ST_NBR_MODES - 1) << ST_MODE_SHIFT)
#define TAPE_NR(minor) ( (((minor) & ~255) >> (ST_NBR_MODE_BITS + 1)) | \
    ((minor) & ~(-1 << ST_MODE_SHIFT)) )
#define TAPE_MODE(minor) (((minor) & ST_MODE_MASK) >> ST_MODE_SHIFT)
static const char *st_formats[] = {
        "",  "r", "k", "s", "l", "t", "o", "u",
        "m", "v", "p", "x", "a", "y", "q", "z"}; 

/* Show the options if visible in sysfs */
static int do_show_options(int mtfd, cmdef_tr *cmd, int argc, char **argv)
{
    int i, fd, options, tapeminor, tapeno, tapemode;
    struct stat stat;
    struct utsname uts;
    char fname[100], buf[20];

    if (uname(&uts) < 0) {
	perror(tape_name);
	return 2;
    }
    sscanf(uts.release, "%d.%d.%d", &i, &tapeno, &tapemode);
    if (i < 2 || tapeno < 6 || tapemode < 26)
	printf("Your kernel (%d.%d.%d) may be too old for this command.\n",
	       i, tapeno, tapemode);

    if (fstat(mtfd, &stat) < 0) {
	perror(tape_name);
	return 1;
    }

    if (!(stat.st_mode & S_IFCHR)) {
	fprintf(stderr, "mt: not a character device.\n");
	return 1;
    }

    tapeminor = minor(stat.st_rdev);
    tapeno = TAPE_NR(tapeminor);
    tapemode = TAPE_MODE(tapeminor);
    tapemode <<= 4 - ST_NBR_MODE_BITS;  /* from st.c */
    sprintf(fname, "/sys/class/scsi_tape/st%d%s/options", tapeno,
	    st_formats[tapemode]);
    /* printf("Trying file '%s' (st_rdev 0x%lx).\n", fname, stat.st_rdev); */

    if ((fd = open(fname, O_RDONLY)) < 0 ||
	read(fd, buf, 20) < 0) {
	fprintf(stderr, "Can't read the sysfs file '%s'.\n", fname);
	return 2;
    }
    close(fd);

    options = strtol(buf, NULL, 0);

    printf("The options set:");
    for (i=0; boolean_tbl[i].name != NULL; i++)
	if (options & boolean_tbl[i].bitmask)
	    printf(" %s", boolean_tbl[i].name);
    printf("\n");

    return 0;
}


/* Print a list of possible density codes */
	static int
print_densities(int fd, cmdef_tr *cmd, int argc, char **argv)
{
    int i, offset;

    printf("Some SCSI tape density codes:\ncode   explanation                   code   explanation\n");
    offset = (NBR_DENSITIES + 1) / 2;
    for (i=0; i < offset; i++) {
	printf("0x%02x   %-28s", density_tbl[i].code, density_tbl[i].name);
	if (i + offset < NBR_DENSITIES)
	    printf("  0x%02x   %s\n", density_tbl[i + offset].code, density_tbl[i + offset].name);
	else
	    printf("\n");
    }
    return 0;
}


/* Try to find out why the command failed */
	static void
test_error(int mtfd, cmdef_tr *cmd)
{
    struct mtget status;

    if (ioctl(mtfd, MTIOCGET, (char *)&status) < 0)
	return;

    if (status.mt_type != MT_ISSCSI1 && status.mt_type != MT_ISSCSI2)
	return;

    if ((cmd->error_tests & ET_ONLINE) && !GMT_ONLINE(status.mt_gstat))
	fprintf(stderr, "mt: The device is offline (not powered on, no tape ?).\n");
    if ((cmd->error_tests & ET_WPROT) && !GMT_WR_PROT(status.mt_gstat))
	fprintf(stderr, "mt: The tape is write-protected.\n");
}