C:\test>perl -le"printf qq[key%07d*value\n], $_ for 1 .. 20e6" >bigfile

C:\test>dir bigfile
11/04/2012  04:34       370,000,001 bigfile


##</code><code>##

C:\test>perl -F\* -anle"$h{$F[0]}=$F[1] }{ print `tasklist /nh /fi \"pid eq $$\"`" bigfile

perl.exe                      3140 Console                    1  4,509,624 K

##</code><code>##

open my $out, '>', 'bigfile' or die $!;
my $l = 0;
while( $l < 350*1024*1024 ){
    my $part1 = join '', map { ('A'..'Z','a'..'z',0..9)[rand(62)] } (0..(rand(30)+10));
    my $part2 = join '', map { ('A'..'Z','a'..'z',0..9)[rand(62)] } (0..(rand(30)+10));
    my $output = "$part1*$part2\n";
    $l += length $output;
    print $out $output;
}

my $filesize = -s 'bigfile';
say 'File size: ', $filesize;