miscutils/mt.c

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