my @SB;
    my $Temp;
    sysopen(DEV, $Device, O_RDWR | O_SYNC) || die("Error: $!\n");
    
    sysseek(DEV,0,0) || die("$!\n");
    sysread(DEV,$SB[0],512) || die("1 $!\n");
    sysseek(DEV,0,0) || die("$!\n");
    sysread(DEV,$SB[1],512) || die("2 $!\n");
    sysseek(DEV,-1024,2) || die("$!\n");
    sysread(DEV,$SB[2],512) || die("3 $!\n");
    sysseek(DEV,-512,2) || die("$!\n");
    sysread(DEV,$SB[3],512) || die("4 $!\n");
    
    if (!($SB[0] eq $SB[1]))
    {
        my @Pair;
        warn("Error, First 2 superblocks do not match! Checking third.
+..");
        foreach my $I (0 .. 1)
        {
            @Pair = ($I,2) if ($SB[$I] eq $SB[2]);
        }
        if (!((@Pair[0]) && (@Pair[1])))
        {
            warn("Error, First 3 superblocks do not match! Checking fo
+urth and final...");
            foreach my $I (0 .. 2)
            {
                @Pair = ($I,3) if ($SB[$I] eq $SB[3]);
            }
            if (!((@Pair[0]) && (@Pair[1])))
            {
                die("All 4 superblock copies are different! This is ma
+jior corruption.\n");
            }
        }
        $SB[0] = $Pair[1];
    }

[download]
I know that they are not equal though, here are the first 1024 bytes: 
Abydos OEFS # hexdump -C -n 1024 /dev/sdf1
00000000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |.........
+.......|
*
00000200  4f 45 46 53 2d 30 30 30  30 2e 30 30 30 30 30 30  |OEFS-0000
+.000000|
00000210  f0 26 3f f0 9d 1f dc 11  93 c2 d9 64 65 f2 e8 c0  |.&?......
+..de...|
00000220  53 74 72 75 01 00 00 00  00 00 00 00 00 00 00 00  |Stru.....
+.......|
00000230  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |.........
+.......|
*
00000400

[download]

In reply to Re^2: Test binary equality? by exodist
in thread Test binary equality? by exodist

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