path: root/miscutils/mt.c (plain)
blob: 6b31696757d796780fb019cb79047affa329e1af

1	/* vi: set sw=4 ts=4: */
2	/*
3	* Licensed under GPLv2 or later, see file LICENSE in this source tree.
4	*/
5	//config:config MT
6	//config: bool "mt"
7	//config: default y
8	//config: help
9	//config: mt is used to control tape devices. You can use the mt utility
10	//config: to advance or rewind a tape past a specified number of archive
11	//config: files on the tape.
12
13	//applet:IF_MT(APPLET(mt, BB_DIR_BIN, BB_SUID_DROP))
14
15	//kbuild:lib-$(CONFIG_MT) += mt.o
16
17	//usage:#define mt_trivial_usage
18	//usage: "[-f device] opcode value"
19	//usage:#define mt_full_usage "\n\n"
20	//usage: "Control magnetic tape drive operation\n"
21	//usage: "\n"
22	//usage: "Available Opcodes:\n"
23	//usage: "\n"
24	//usage: "bsf bsfm bsr bss datacompression drvbuffer eof eom erase\n"
25	//usage: "fsf fsfm fsr fss load lock mkpart nop offline ras1 ras2\n"
26	//usage: "ras3 reset retension rewind rewoffline seek setblk setdensity\n"
27	//usage: "setpart tell unload unlock weof wset"
28
29	#include "libbb.h"
30	#include <sys/mtio.h>
31
32	/* missing: eod/seod, stoptions, stwrthreshold, densities */
33	static const short opcode_value[] = {
34	MTBSF,
35	MTBSFM,
36	MTBSR,
37	MTBSS,
38	MTCOMPRESSION,
39	MTEOM,
40	MTERASE,
41	MTFSF,
42	MTFSFM,
43	MTFSR,
44	MTFSS,
45	MTLOAD,
46	MTLOCK,
47	MTMKPART,
48	MTNOP,
49	MTOFFL,
50	MTOFFL,
51	MTRAS1,
52	MTRAS2,
53	MTRAS3,
54	MTRESET,
55	MTRETEN,
56	MTREW,
57	MTSEEK,
58	MTSETBLK,
59	MTSETDENSITY,
60	MTSETDRVBUFFER,
61	MTSETPART,
62	MTTELL,
63	MTWSM,
64	MTUNLOAD,
65	MTUNLOCK,
66	MTWEOF,
67	MTWEOF
68	};
69
70	static const char opcode_name[] ALIGN1 =
71	"bsf" "\0"
72	"bsfm" "\0"
73	"bsr" "\0"
74	"bss" "\0"
75	"datacompression" "\0"
76	"eom" "\0"
77	"erase" "\0"
78	"fsf" "\0"
79	"fsfm" "\0"
80	"fsr" "\0"
81	"fss" "\0"
82	"load" "\0"
83	"lock" "\0"
84	"mkpart" "\0"
85	"nop" "\0"
86	"offline" "\0"
87	"rewoffline" "\0"
88	"ras1" "\0"
89	"ras2" "\0"
90	"ras3" "\0"
91	"reset" "\0"
92	"retension" "\0"
93	"rewind" "\0"
94	"seek" "\0"
95	"setblk" "\0"
96	"setdensity" "\0"
97	"drvbuffer" "\0"
98	"setpart" "\0"
99	"tell" "\0"
100	"wset" "\0"
101	"unload" "\0"
102	"unlock" "\0"
103	"eof" "\0"
104	"weof" "\0";
105
106	int mt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
107	int mt_main(int argc UNUSED_PARAM, char **argv)
108	{
109	const char *file = "/dev/tape";
110	struct mtop op;
111	struct mtpos position;
112	int fd, mode, idx;
113
114	if (!argv[1]) {
115	bb_show_usage();
116	}
117
118	if (strcmp(argv[1], "-f") == 0) {
119	if (!argv[2] || !argv[3])
120	bb_show_usage();
121	file = argv[2];
122	argv += 2;
123	}
124
125	idx = index_in_strings(opcode_name, argv[1]);
126
127	if (idx < 0)
128	bb_error_msg_and_die("unrecognized opcode %s", argv[1]);
129
130	op.mt_op = opcode_value[idx];
131	if (argv[2])
132	op.mt_count = xatoi_positive(argv[2]);
133	else
134	op.mt_count = 1; /* One, not zero, right? */
135
136	switch (opcode_value[idx]) {
137	case MTWEOF:
138	case MTERASE:
139	case MTWSM:
140	case MTSETDRVBUFFER:
141	mode = O_WRONLY;
142	break;
143
144	default:
145	mode = O_RDONLY;
146	break;
147	}
148
149	fd = xopen(file, mode);
150
151	switch (opcode_value[idx]) {
152	case MTTELL:
153	ioctl_or_perror_and_die(fd, MTIOCPOS, &position, "%s", file);
154	printf("At block %d\n", (int) position.mt_blkno);
155	break;
156
157	default:
158	ioctl_or_perror_and_die(fd, MTIOCTOP, &op, "%s", file);
159	break;
160	}
161
162	return EXIT_SUCCESS;
163	}
164