I have written a small and simple primes generator that just prints out a file that contains a calculated prime number on a new line. But the saving behaviour of this script is rather weird. When I let it run for just some seconds the file is empty. When I wait some more everything is fine and the file seems in order (although it seems to always stop with just 2 digits in the last line). Can anyone explain me why this is happening?

As a side question I would like to ask if there's a better way to check if a number is an int or float than the regexp I used in my script. 

open ( SAVE, '>primes.dat' ) or die "Couldn't open primes.dat";

@primes = ( 2 );
$testnumber = 3;

while ( 1 )
{
    foreach $placeholder ( @primes )
    {
        if ( ( $testnumber / $placeholder ) =~ /^[+-]?\d+$/ ) 
        {
            $testnumber = $testnumber + 2;
            next;
        }
        
        if ( $placeholder == $primes[-1] ) 
        {
            push ( @primes, $testnumber );
            print SAVE "$testnumber\n";
        }
        
        next;
    }
}

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Thanks

In reply to Strange saving behaviour by Mandor

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