my $count = 20;
print 'a' x $count;

my $size = 300;
my $counter = $size * 1024;
open(file, ">".$size."kb.txt");
        
for(my $i=0; $i < $counter; $i++)
{
        print file "*"; 
}       
close(file);

use strict;
use warnings;

my $size = 300;
open my $file, ">", $size . "kb.txt" or die $!;

print $file "*" x 1024 for 1 .. $size;

close $file;

#!/usr/bin/perl
use strict;
use warnings;

my $size = 1_000_000;

open my $bigfile, '>', 'bigfile' or die $!;
seek $bigfile, $size-1, 0;
print $bigfile "\0";
close $bigfile;