$PRE    = '\[\s*(';
$VALID1 = '[-a-zA-Z0-9_.* \t\n]';
$VALID2 = '[-a-z0-9_.*\n]';
$VALID3 = '[a-zA-Z]';
$VALID4 = '[-a-zA-Z0-9]';
$PST    = ')\s*\]';
while (<DATA>)
{
    s/\\n/\n/g; #Are these harmless if
    s/\\t/\t/g; #not needed???
    print "yep\n"  if m/$PRE($VALID1+)$PST\s*
                        $PRE($VALID2+)$PST\s*
                        $PRE($VALID3+)$PST\s*
                        $PRE($VALID4+)$PST\s*
                      /x;
}


__DATA__
[TEST \n DATA] [ TEST DATA ]  [ 2345423 ] [ TEST\tDATA ]\n
[TEST \n DATA] [ TEST DATA ]  [ 2345423 ] [ TEST DATA ]\n
[TEST \n DATA] [ TEST DATA ]  [ 2345423 ] [ TEST\tDATA ]\n