#!perl -w

my $test = (
  "olive&(popeye|bluto)",
  "(tom&jerry)|(sylvester&tweety)",
  "moe&(shemp|curly|joe)&larry",
  "tom&jerry|sylvester&tweety", # valid
  "moe ( shemp | curly | joe ) larry", # also valid
  "moe(&shemp|curly|joe)&larry", # invalid: "(&" instead of "&("
  "moe ( shemp | curly | joe", # invalid: missing ")" raises an error
)[(shift) - 1];

my $expr = $test;

$expr =~ s/(\w+)/"(?=.*\\b($1)\\b)"/ge;
$expr =~ s/[\&\s]//g;
$expr = "^($expr)";

print "$test\n$expr\n----\n";

while (<DATA>) {
  print $_ if /$expr/;
}

__DATA__
tom,jerry
jerry,tom
jerry,tomas
sylvester,tweety
tweeter,sylvester
tom,sylvester
popeye,olive
olive,brutus
moe,larry
shemp,curly,joe
larry,moe
larry,curly,moe