use strict;
use warnings;
use Data::Dumper;

my %results = do
{
		local $/ = ''; # paragraph mode
		map { /TYPE (\S+)/ => 
					{ 
							'cause'  => (/CAUSE (\S+)/ ?$1:'UNDEF'), 
							'effect' => (/AFFECT (\S+)/?$1:'UNDEF'),
					}
		} <DATA>;
};
print Dumper \%results;

__DATA__
TYPE VALUE1 EQUALS MAIN
CAUSE FAIL
AFFECT ERROR
ENDTYPE