$min = some number if defined
$max = some number if defined
$Files = some number 
$IdleTime = some number 

$if = 0;

$if = ($Files >= $max)
   if defined $max;

$if ||= ($IdleTime >= $min)
   if defined $min;

if ($if) {
    print "hi";
} else {
    print "hello";
}