sub process_command_line_args {
    #set default values for dynamic config settings
    my ($layout,$wait_for_child,$wait_for_exec,$prompt,$configf,$quiet,$outf,$debug,$batchsize,$proto,$tacacs,$verbose,$header,@maildst) = (0,120,3,1,"$name.cfg",1,"$name.csv",0,0,"none",0,0);

    GetOptions ( ...)
    ...

    my @args = ($layout,$wait_for_child,$wait_for_exec,$name,$prompt,$configf,$quiet,$outf,$debug,$batchsize,$proto,$tacacs,$verbose,$header,$mailref,$path);
    return \@args;
}

##</code><code>##

sub Main {
    my %CONFIG;
    initialize_config_hash(\%CONFIG);
    get_command_line_args(\%CONFIG);
    validate_command_line_args(\%CONFIG);
    get_username_and_password_from_stdin(\%CONFIG) if $CONFIG{prompt};
    
    ...
}

sub initialize_config_hash {
    my $CONFIG = shift;
    %$CONFIG = (
        quiet          => 0      , cfg       => "$name.cfg"         ,
        verbose        => 0      , outcsv    => "$name.csv"         ,
        debug          => 0      , proto     => "none"              ,
        prompt         => 1      , header    => undef               ,
        layout         => 0      , maildst   => []                  ,
        wait_for_child => 120    , mail_to   => ""                  ,
        wait_for_exec  => 0      , mail_from => "NMS-script@me.net" ,
        batchsize      => 0      , mail_sub  => ""                  ,
        tacacs         => 0      , mail_cc   => ""                  ,
        tacuser        => "user" , mail_data => ""                  ,
        tacpass        => "pass" ,
    );
}

sub get_command_line_args {
    my $CONFIG = shift;
    GetOptions (
        'layout|l'            => \$CONFIG->{layout},
        'file-based-auth|f'   => sub { \$CONFIG->{prompt} = 0; },
        'prompt-based-auth|p' => sub { \$CONFIG->{prompt} = 1; },
        ...
    )
    ...
}

##</code><code>##

$WARN = 0; #supress flow control warning in following block due to exiting anon sub
LOOPCTRL: while ($lb < 10){
    $exp->expect(...
        [ ..., sub {...
            $lb++;
            next LOOPCTRL; }],
        ...
    );
    $exp->expect(...
        [ ..., sub {...
            last LOOPCTRL; }]
    );
}
$WARN = 1; # reset to default

##</code><code>##

while (...) {
    next if $exp->expect(...
        ...
    );
    last if $exp->expect(...
        ...
    );
}

##</code><code>##

use strict;
use warnings;

# warnings coming from here will be printed

{
  no warnings;
  
  # warnings coming from here will NOT be printed
}

# warnings coming from here will be printed

##</code><code>##

  # Don't warn about exiting subs via loop control:
  no warnings 'exiting';
  
  # Don't warn about using undef in numeric or string operations:
  no warnings 'uninitialized';

##</code><code>##

{
  local $SIG{__WARN__} = sub {};
  
  # call the noisy module function here
}

# warnings coming from here will not be affected

##</code><code>##

\%{ $CONFIG }
\%$CONFIG

##</code><code>##

my $range = '1000000';
my $rand = int(rand($range)); ##generate random temp-db filename to allow for simultanous script execution

...
  tempdb => "$path/$rand.db",

##</code><code>##

my $foo = $_[0];

##</code><code>##

my $foo = shift;

##</code><code>##

my ($foo) = @_;