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Getopt::Long - Handle command line options

You can use Getopt::Long to handle options for command line arguments.

# Loading modules and importing functions
use Getopt::Long 'GetOptions';

Consider specifying the following options with command line arguments:

# Specify the option with the command line argument.
perl script.pl - enable_cache - max_clients = 5 - type = single config.init

You can easily handle such command line options using the GetOptions function .

# Handling command line argument options with GetOptions

# Set default value
my $enable_cache;
my $max_clients = 5;
my $type = 'prefork';

# Optional processing
GetOptions(
  'enable_cache' => \$enable_cache,
  'max_clients = i'=> \$max_clients,
  'type = s'=> \$type
);

Receives non-option arguments
my $conf_file = shift;

How to use the GetOptions function.

# Arguments of GetOptions
GetOptions(
  'Option name = Value type' =>'Variable to save',
  'Option name = Value type' =>'Variable to save',
  ...
);

For "Option name = Type", specify the option name and value type. If the option name is a boolean value, the value type is omitted. If the option name is an integer, specify i as the value type. If the option name is a string, specify s as the value type.

# Authenticity value
'enable_cache' => \$enable_cache

# Integer
'max_clients = i'=> \$max_clients

# String
'type = s'=> \$type

For "Variable to save", specify a reference for a scalar variable. Set the default value first and pass it as a reference to the GetOptions argument.

# Set default value
my $max_clients = 5;

# Specify a scalar variable reference in the argument
GetOptions(
  'max_clients = i'=> \$max_clients,
);

Command line options can also be specified by abbreviated names. The initial letter of the option name is the abbreviated name.

# Specify command line argument options with abbreviated name
perl script.pl -e -m = 5 -t = single config.init

= Can be omitted.

# Omit equal
perl script.pl - enable_cache - max_clients 5 - type single config.init