######################################################## # Return true if all parameters are either defined or # undefined. Return false if there is a mix. ######################################################## sub defined_all_or_none { #my $self=shift; # This is a module, remember? shift; @_||(return 1); if(defined($_[0])) { for(@_) { unless(defined) { return 0; } } } else { for(@_) { if(defined) { return 0; } } } 1; }