if ($name =~ s/^r.wpi//i) { print ("$name fits\n"); }
else                      { print ("$name does not fit\n"); }

##</code><code>##

my $name = "ipw.raxwgorga";

if ((substr($name, 0,5) eq "ipw.r") && ( (sort (split(undef, substr($name, 5, length($name) - 5))))[0] eq substr($name, 5,1)))
{
	$name = "r.wpi".$name;
};