I have a 3 gig binary file that I need to edit. I'm running into memory problems since I have to pack and unpack the file. I've tried running on a unix, linux and windows machine with no luck. Any ideas on what I can do? I basically need to open the file and edit it at a bit level. I need to find certain bit patterns and remove them. I've tried to edit using hex characters but have found when I remove the character instead of only 8 bits being removed 16 get removed. Have no idea why that happens.

Per requests below is the code:

#!/usr/local/bin/perl -w

undef $/; #Clear the record seperator.
$| = 1;  #Don't Buffer data.  Write out when available.

open IN, "$ARGV[0]";

binmode IN;  #Use binary mode so windows/DOS won't complain

#Convert original file into binary and write to $final

while (<IN>) { #Loop thru file and convert file to 1's/0's
     $array = unpack("B*", $_);
     open OUT, ">>tmp";
     print OUT "$array";
     close OUT;
     undef $array;
}

close IN;

print "Finished unpacking data.\n\n";

undef $/;

open IN, "tmp";

#Extract the necessary data bits

while (<IN>) {

     $_ =~ s/11110100.{8}(.{1520})11110100.{8}(.{464}).{1056}/$1$2/g;

     $final - pack("B*", $_); #Conver data back to original binary for
+mat

     open OUT, ">>$ARGV[1]";

     print OUT "$final";

     close OUT;

     undef $final;
}

close IN;

unlink "tmp";

print "Finished converting to binary.\n\n";

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20041021 Janitored by Corion: Added formatting

In reply to Out of memory problems by tperdue

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