open SEARCH, $file_to_search or die $!;
my $text = do { local $/; <SEARCH> };
close SEARCH;

my $count = 1;

while ( $text =~ /($regex_to_search_for)/sg ) {
  open FOUND, '>', "found$count.txt" or die $!;
  print FOUND $1;
  ++$count;
}