There are a number of ways of measuring speed. At the end of the day "time to correct solution" is much more important than "time to execute the program". In this case the (cleaned up) code that you supplied ran in 10 seconds on my system. However the Perl code is about 5 times shorter than the C code so the time to write the Perl code will have been less and the time to debug it will have been much less!

What do you like better:

• coding five minutes + 10 seconds run time
• coding fifteen minutes + 1 second run time

# Test data generator
use strict;
use warnings;

open outFile, "> data.txt";
print outFile ("0," x 99) . "$_," . ("0," x 10) . "0\n" for (1..100000
+0);
close outFile;


# Sum test
use strict;
use warnings;
use Time::HiRes;

my $val = 0;
my @arr;
my $start = time ();
open inFile, "< data.txt";
while (<inFile>)
    {
    /(?:\d+,){99}(\d+),/;
    $val += $1;
    }
close inFile;
print "Final: [$val] (elapsed time " . (time () - $start) . " seconds\
+n";
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