my $PREFIX = '/home/xpost-scripts';

my %xscripts = ( site_a => 'a_funct', site_b => 'b_funct' );
foreach (keys(%xscripts)) {
  eval { require ("$PREFIX/$_") };
  print STDERR "Warning: File $_ had errors: '$@'\n" if($@);
}

# ... Here, we grabbed the Function name from a DB query. It's a hash for this example.
foreach (keys(%xscripts)) {
  if (defined($xscripts{$_}) && ref($xscripts{$_}) && UNIVERSIAL::isa($xscripts{$_}, 'CODE')) {
     &$xscripts{$_}("A parameter");
  } else {
    print STDERR "Error. Could not call function $xscripts{$_}\n";
  }
}