10 fprint(2, "usage: fossil/epoch fs [new-low-epoch]\n");
11 threadexitsall("usage");
15 threadmain(int argc, char **argv)
26 if(argc == 0 || argc > 2)
29 if((fd = open(argv[0], argc==2 ? ORDWR : OREAD)) < 0)
30 sysfatal("open %s: %r", argv[0]);
32 if(pread(fd, buf, HeaderSize, HeaderOffset) != HeaderSize)
33 sysfatal("reading header: %r");
34 if(!headerUnpack(&h, buf))
35 sysfatal("unpacking header: %r");
37 if(pread(fd, buf, h.blockSize, (vlong)h.super*h.blockSize) != h.blockSize)
38 sysfatal("reading super block: %r");
40 if(!superUnpack(&s, buf))
41 sysfatal("unpacking super block: %r");
43 print("epoch %d\n", s.epochLow);
45 s.epochLow = strtoul(argv[1], 0, 0);
47 if(pwrite(fd, buf, h.blockSize, (vlong)h.super*h.blockSize) != h.blockSize)
48 sysfatal("writing super block: %r");