in reply to Re^7: dynamic extractor based off static references in file (perl)
in thread dynamic extractor based off static references in file (perl)

pack n An unsigned short (16-bit) in "network" (big-endian) order. 
my $bytes = qq[\4\xC0];
my $ushortbe = unpack q[n], $bytes;
printf qq[0x%04X  0b%b  %d\n], ($ushortbe ) x 3;
__END__
0x04C0  0b10011000000  1216

[download]

but in all the code you've pasting you've been reading 3 bytes, a 16 bit integer takes 2 bytes ( 2x8) not 3 , so .... :)

  • Comment on Re^8: dynamic extractor based off static references in file (perl)
  • Download Code

Replies are listed 'Best First'.
Re^9: dynamic extractor based off static references in file (perl)
by james289o9 (Acolyte) on Dec 09, 2013 at 19:49 UTC
    the three bytes i am reading are just references. i am not worried about anything except putting that reference into a variable, then calling that variable to seek to the actual data. this script is just to extract data in a file. say for instance if at 0x15 there is "00 04 C0". this script will read those bytes, then put the reference "00 04 C0" into variable $buffer1 (which is the data location further into the file). then it will get filesize at address 0x1D and put that into $buffer2. then it uses those two references to seek to the actual data further into the file.
    does that help you understand what i am trying to do any better? i am able to extract 25 files (the actual data the references point to) and am able to get the file names and everything with this little script. works a treat for me tbh. if i only read two bytes, then i wouldnt get part of alot of references. the references are never longer than 3 bytes. thats why i used read 0x03.
    this data changes constantly from file to file. the references never changes spots but the actual files swap spots and there is no way to statically seek to and get this info. this is sort of a dynamic extractor. it will extract the data and name the file all in a easy to run script.
    hope you understand. if you want i can send you the file and the script for you to see what im talking about. message me your email or something so you can see what i mean. it really works a treat man, and saves me alot of work from having to manually extracting this data with a hex editor.
    i am about to update the original post with the finished script. take a look at it and see if you can gimme a better way of doing it. like i say i am open to any ideas, and if you want i can send you the file itself and you can use the script to see what i am accomplishing.
[reply]

In Section Seekers of Perl Wisdom