Subversion Repositories planix.SVN

#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);
}