in reply to Re: dynamic extractor based off static references in file (perl)
in thread dynamic extractor based off static references in file (perl)

I have this code so far: 
open(my $infile, '<', "./file") or die "Cannot open file: $!";
binmode($infile);

open(my $outfile, '>', "./reference1") or die "Cannot create file: $!"
+;
binmode($outfile);

my $file = $infile;

my $buffer = '';
sysseek $file, 0x15, 0;
sysread $file, $buffer, 0x03;
syswrite $outfile, $buffer;
close $outfile;

system ( 'pause' );

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I can get the first reference and I should be able to get the second reference without trouble. I am having problems figuring out how to put the $buffer into $reference.
i tried this but it didnt work to well ofcourse: 
my $reference = $buffer;
print $reference;

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it prints the data from $infile, but not in binary form. i guess my question really is, how can i put $buffer (binary data) into $location? any clarifications on what to do would be very much appreciated.

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Re^3: dynamic extractor based off static references in file (perl)
by Anonymous Monk on Dec 06, 2013 at 08:19 UTC

    it prints the data from $infile, but not in binary form

    Sure it does, you used binmode on both filehandles, you read the data, its binary form, there is no doubt; if you need a different format you'll need to do something about it

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      Yes sir, and that happens to be where im stuck at. when i try to put the $buffer (location) into the variable $reference, it works. but when i try to use $location in sysseek i gives me the error: 
      Argument "\0^D&" isn't numeric in sysseek

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        Argument "\0^D&" isn't numeric in sysseek

        Based on those bytes/octets, to turn them a "number", it all depends on what kind ... see pack, unpack, perlpacktut

        Just guessing at the right one (guessing is bad, knowing is better) 

        use Data::Dump qw/ dd pp /;
dd( unpack q{c*}, "\0^D&"  );# (0, 94, 68, 38)
dd( unpack q{C*}, "\0^D&"  );# (0, 94, 68, 38)
dd( unpack q{W*}, "\0^D&"  );# (0, 94, 68, 38)
dd( unpack q{s*}, "\0^D&"  );# (24064, 9796)
dd( unpack q{S*}, "\0^D&"  );# (24064, 9796)
dd( unpack q{l*}, "\0^D&"  );# 642014720
dd( unpack q{L*}, "\0^D&"  );# 642014720
dd( unpack q{i*}, "\0^D&"  );# 642014720
dd( unpack q{I*}, "\0^D&"  );# 642014720
dd( unpack q{n*}, "\0^D&"  );# (94, 17446)
dd( unpack q{N*}, "\0^D&"  );# 6177830
dd( unpack q{v*}, "\0^D&"  );# (24064, 9796)
dd( unpack q{V*}, "\0^D&"  );# 642014720
dd( unpack q{q*}, "\0^D&"  );# ()
dd( unpack q{Q*}, "\0^D&"  );# ()

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