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Here is a snippet from some code that I wrote "many moons ago". This code will run not just a "little bit" faster than a Win command line...the performance difference is HUGE, even with just 8K buffer. If the search in the buffer can be run with say just two of these 8K buffers, it will be very, very fast. This is a copy routine, but same principle works for reading large files. showfailed() is a tricky thing that is sort of like die() and warn() and has a GUI display context. For the purpose here, it doesn't even matter.

##################
# Binary File Copy and Append
#
# bcopy($output, @input_files);
#              # first element is the output file path, 
#              # then input files: file1, file2...file n.
sub bcopy()
{
   (my $out, my @in_list)=@_;
   open (OUTBIN, ">", "$out") || showfailed
                                ("unable to open $out");
   binmode(OUTBIN)        || showfailed
                              ("unable to set binmode $out");
   
   foreach my $infile (@in_list)
   {
       open(INBIN, "<", "$infile")|| showfailed 
                                      ("unable to open $infile");  
       binmode(INBIN)           || showfailed
                                    ("unable to set binmode $infile");
       while (read(INBIN, my $buff, 8 * 2**10))
       {
          print OUTBIN $buff;
       }
       close(INBIN) || showfailed("unable to close $infile");  
       print "$infile appended to $out\n";
   }
   close(OUTBIN)  || showfailed("unable to close $out");
} #end of bcopy
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In reply to Re^2: Reading a VERY LARGE file with SINGLE line as content! by Marshall
in thread Reading a VERY LARGE file with SINGLE line as content! by biswanath_c

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