use strict; 
 
my %allowed = ( 
    "" => "[\w\.\-]", 
    "\"" => "[^\"]", 
    "\'" => "[^\']" 
); 
my @lines = ( 
    "id=\"abc\"", # expected: abc 
    "id=\'abc\'", # expected: abc 
    "id=\"abc def\"", # expected: abc def 
    "id=abc", # expected: abc 
    "id=abc def", # expected: abc 
); 
 
foreach my $line ( @lines ) { 
    print $line; 
    if( $line =~ /\w=([\'\"]?)($allowed{\1}*)\1(.*)$/ ) { 
        print " => $2/$3\n"; 
    } 
    else { 
        print " didn't match\n"; 
    } 
}