die $help unless $ARGV[1];
map { /^-?\d+$/ or die "Invalid input $_\n" } @ARGV;

# . . . and later . . .
sub HELP_MESSAGE {
  print $help;
}

##</code><code>##

/home/ren/bin/ies version 1.0 calling Getopt::Std::getopts (version 1.05),
running under Perl version 5.8.8.


Usage: series [-OPTIONS [-MORE_OPTIONS]] [--] [PROGRAM_ARG1 ...]


The following single-character options are accepted:
        Boolean (without arguments): -s

Options may be merged together.  -- stops processing of options.