comment on

Given a binary file, I want to search for a section of content, and return the next few bytes in the file. Currently, I am using something like this code:

   my $file = '/path/to/binaryfile';

   # string to match, in hex
   my $matchstr = '53005f00560045005200530049004f004e005f0049004e00460
+04f0000000000bd04effe00000100';

   # read in file and convert to a textual (hex) representation
   open(FILE,"$file") or die "Unable to open file: $!\n";
   binmode(FILE);
   my $binhex = '';
   while (eof(FILE) != 1) {
      my $buf;
      my $num_byte_read = read(FILE,$buf,16);
      foreach ($buf =~ m/./gs) {
         $binhex .= sprintf("%02x",ord($_));
      }
   }
   close(FILE);
   
   # search it
   if ($binhex =~ /$matchstr(\S\S\S\S)(\S\S\S\S)(\S\S\S\S)(\S\S\S\S)/)
+ {
      print "Found: " . join(',',($1,$2,$3,$4));
   }
[download]

This is unbearably slow for large files. I'd like to search without having to convert to/from hex. Any ideas on how to accomplish this, or another way to speed up the parsing?

BTW, the searching section of the code works very well. It's the conversion to hex that takes all the time.

Cheers,
Shendal

Edit by tye

In reply to Searching binary data by Shendal

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