1 6f4d00ee 2013-09-23 0intro #include <u.h>
 2 6f4d00ee 2013-09-23 0intro #include <libc.h>
 3 6f4d00ee 2013-09-23 0intro 
 4 6f4d00ee 2013-09-23 0intro void
 5 6f4d00ee 2013-09-23 0intro usage(void)
 6 6f4d00ee 2013-09-23 0intro {
 7 6f4d00ee 2013-09-23 0intro 	fprint(2, "usage: fossil/last disk\n");
 8 6f4d00ee 2013-09-23 0intro 	exits("usage");
 9 6f4d00ee 2013-09-23 0intro }
10 6f4d00ee 2013-09-23 0intro 
11 6f4d00ee 2013-09-23 0intro void
12 6f4d00ee 2013-09-23 0intro main(int argc, char **argv)
13 6f4d00ee 2013-09-23 0intro {
14 6f4d00ee 2013-09-23 0intro 	int fd, bs, addr;
15 6f4d00ee 2013-09-23 0intro 	char buf[20];
16 6f4d00ee 2013-09-23 0intro 
17 6f4d00ee 2013-09-23 0intro 	ARGBEGIN{
18 6f4d00ee 2013-09-23 0intro 	default:
19 6f4d00ee 2013-09-23 0intro 		usage();
20 6f4d00ee 2013-09-23 0intro 	}ARGEND
21 6f4d00ee 2013-09-23 0intro 
22 6f4d00ee 2013-09-23 0intro 	if(argc != 1)
23 6f4d00ee 2013-09-23 0intro 		usage();
24 6f4d00ee 2013-09-23 0intro 
25 6f4d00ee 2013-09-23 0intro 	if((fd = open(argv[0], OREAD)) < 0)
26 6f4d00ee 2013-09-23 0intro 		sysfatal("open %s: %r", argv[0]);
27 6f4d00ee 2013-09-23 0intro 
28 6f4d00ee 2013-09-23 0intro 	werrstr("end of file");
29 6f4d00ee 2013-09-23 0intro 	if(seek(fd, 131072, 0) < 0 || readn(fd, buf, 20) != 20)
30 6f4d00ee 2013-09-23 0intro 		sysfatal("error reading %s: %r", argv[0]);
31 6f4d00ee 2013-09-23 0intro 	fmtinstall('H', encodefmt);
32 6f4d00ee 2013-09-23 0intro 	if(memcmp(buf, "\x37\x76\xAE\x89", 4) != 0)
33 6f4d00ee 2013-09-23 0intro 		sysfatal("bad magic %.4H != 3776AE89", buf);
34 6f4d00ee 2013-09-23 0intro 	bs = buf[7]|(buf[6]<<8);
35 6f4d00ee 2013-09-23 0intro 	addr = (buf[8]<<24)|(buf[9]<<16)|(buf[10]<<8)|buf[11];
36 6f4d00ee 2013-09-23 0intro 	if(seek(fd, (vlong)bs*addr+34, 0) < 0 || readn(fd, buf, 20) != 20)
37 6f4d00ee 2013-09-23 0intro 		sysfatal("error reading %s: %r", argv[0]);
38 6f4d00ee 2013-09-23 0intro 	print("vac:%.20lH\n", buf);
39 6f4d00ee 2013-09-23 0intro 	exits(0);
40 6f4d00ee 2013-09-23 0intro }