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