$ perl -MData::Dumper -le '%h = map { $_ => /^FOO((?!BA[RZ]$).*)/ ? $1 : q(does NOT match) } qw/FOO FOOZIM FOOBAR FOOA FOOBAZ FOOBARX/; $Data::Dumper::Terse = $Data::Dumper::Indent = 1; print Dumper \%h'
{
  'FOOBAR' => 'does NOT match',
  'FOOZIM' => 'ZIM',
  'FOOA' => 'A',
  'FOOBARX' => 'BARX',
  'FOOBAZ' => 'does NOT match',
  'FOO' => ''
}