busybox/miscutils/mt.c
Denis Vlasenko 8add068573 mt: eliminate vector of structures with pointers (bad for libbusybox).
It's a win for static build too:

function                                             old     new   delta
opcode_name                                            -     213    +213
opcode_value                                           -      68     +68
mt_main                                              281     256     -25
opcodes                                              280       -    -280
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 0/1 up/down: 281/-305)          Total: -24 bytes
   text    data     bss     dec     hex filename
 767403     974    9420  777797   bde45 busybox_old
 767224     974    9420  777618   bdd92 busybox_unstripped
2007-10-11 19:38:59 +00:00

143 lines
2.5 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
#include <sys/mtio.h>
/* missing: eod/seod, stoptions, stwrthreshold, densities */
static const short opcode_value[] = {
MTBSF,
MTBSFM,
MTBSR,
MTBSS,
MTCOMPRESSION,
MTEOM,
MTERASE,
MTFSF,
MTFSFM,
MTFSR,
MTFSS,
MTLOAD,
MTLOCK,
MTMKPART,
MTNOP,
MTOFFL,
MTOFFL,
MTRAS1,
MTRAS2,
MTRAS3,
MTRESET,
MTRETEN,
MTREW,
MTSEEK,
MTSETBLK,
MTSETDENSITY,
MTSETDRVBUFFER,
MTSETPART,
MTTELL,
MTWSM,
MTUNLOAD,
MTUNLOCK,
MTWEOF,
MTWEOF
};
static const char opcode_name[] ALIGN1 =
"bsf" "\0"
"bsfm" "\0"
"bsr" "\0"
"bss" "\0"
"datacompression" "\0"
"eom" "\0"
"erase" "\0"
"fsf" "\0"
"fsfm" "\0"
"fsr" "\0"
"fss" "\0"
"load" "\0"
"lock" "\0"
"mkpart" "\0"
"nop" "\0"
"offline" "\0"
"rewoffline" "\0"
"ras1" "\0"
"ras2" "\0"
"ras3" "\0"
"reset" "\0"
"retension" "\0"
"rewind" "\0"
"seek" "\0"
"setblk" "\0"
"setdensity" "\0"
"drvbuffer" "\0"
"setpart" "\0"
"tell" "\0"
"wset" "\0"
"unload" "\0"
"unlock" "\0"
"eof" "\0"
"weof" "\0";
int mt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int mt_main(int argc, char **argv)
{
const char *file = "/dev/tape";
struct mtop op;
struct mtpos position;
int fd, mode, idx;
if (argc < 2) {
bb_show_usage();
}
if (strcmp(argv[1], "-f") == 0) {
if (argc < 4) {
bb_show_usage();
}
file = argv[2];
argv += 2;
argc -= 2;
}
idx = index_in_strings(opcode_name, argv[1]);
if (idx < 0)
bb_error_msg_and_die("unrecognized opcode %s", argv[1]);
op.mt_op = opcode_value[idx];
if (argc >= 3)
op.mt_count = xatoi_u(argv[2]);
else
op.mt_count = 1; /* One, not zero, right? */
switch (opcode_value[idx]) {
case MTWEOF:
case MTERASE:
case MTWSM:
case MTSETDRVBUFFER:
mode = O_WRONLY;
break;
default:
mode = O_RDONLY;
break;
}
fd = xopen(file, mode);
switch (opcode_value[idx]) {
case MTTELL:
ioctl_or_perror_and_die(fd, MTIOCPOS, &position, "%s", file);
printf("At block %d\n", (int) position.mt_blkno);
break;
default:
ioctl_or_perror_and_die(fd, MTIOCTOP, &op, "%s", file);
break;
}
return EXIT_SUCCESS;
}