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#include <u.h>
#include <libc.h>
void
usage(void)
{
fprint(2, "usage: fossil/last disk\n");
exits("usage");
}
void
main(int argc, char **argv)
{
int fd, bs, addr;
char buf[20];
ARGBEGIN{
default:
usage();
}ARGEND
if(argc != 1)
usage();
if((fd = open(argv[0], OREAD)) < 0)
sysfatal("open %s: %r", argv[0]);
werrstr("end of file");
if(seek(fd, 131072, 0) < 0 || readn(fd, buf, 20) != 20)
sysfatal("error reading %s: %r", argv[0]);
fmtinstall('H', encodefmt);
if(memcmp(buf, "\x37\x76\xAE\x89", 4) != 0)
sysfatal("bad magic %.4H != 3776AE89", buf);
bs = buf[7]|(buf[6]<<8);
addr = (buf[8]<<24)|(buf[9]<<16)|(buf[10]<<8)|buf[11];
if(seek(fd, (vlong)bs*addr+34, 0) < 0 || readn(fd, buf, 20) != 20)
sysfatal("error reading %s: %r", argv[0]);
print("vac:%.20lH\n", buf);
exits(0);
}
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