#! perl -slw
use strict;

sub switch{
	die "Bad switch expression at @{[ caller() ]}\n"  
          unless $_[0] =~ /^\w+$/;
	eval{ goto "case_$_[0]" } or goto default;
}

for my $expr ( 1 .. 10, 'fred', "1;system('rm -rf /')"  ) {
	switch( $expr ); {
		case_1:		print '1'; last;
		case_2: 	   print '2'; last;
		case_3:		print '3'; last;
		case_4:		print '4'; last;
		case_5:		;
		case_6:		print '5 or 6'; last;
		case_fred:	 print 'fred'; last;
		default: 	  print "default";
	}
}

__END__
P:\test>test
1
2
3
4
5 or 6
5 or 6
default
default
default
default
fred
Bad switch expression at main P:\test\test.pl8 10