# X is the "default action"

# do X with an exception that when A,B and C are all false
# then don't do X

unless (!A and !B and !C) {X}

# if anybody is true then they all can't be false
# so we do X unless anybody is true (meaning they
# can't all be false)

unless (A or B or C) {X}
-------

unless ( (!($args =~ /\-rs(\s+)(\S+)/)) && 
         (!($args =~ /\-p(\s+)(\S+)/))  && 
         (!($args =~ /\-P(\s+)(\S+)/))     ) 
   {.....

# I figure this is easier to understand:

unless ( $args =~ /\-rs(\s+)(\S+)/ or 
         $args =~ /\-p(\s+)(\S+)/  or 
         $args =~ /\-P(\s+)(\S+)/     ) 
   {....