Main( @ARGV );
exit( 0 );
sub Main {
    my( $command, @args ) = @_;
    my %commands = ( example => \&Example, help => \&Help );
    my $action = $commands{lc $command} || \&Help;
    $action->( @args );
}
sub Example {
    my( $infile, $outfile ) = @_;
    use autodie;
    open my $out, '>', $outfile ;
    ...
}