Subroutines in the Opts Package

The Opts package includes the following subroutines:

■	add_options

■	get_option

■	option_is_set

■

parse

■

validate

■

usage

add_options

Adds custom options so that they can be submitted to parsing and validation. After the script has validated the options, the script can use them at run time.

Parameters

Parameter	Description
%opts	Name of the hash variable that consists of the option name and its attributes.

Returns

Returns nothing.

get_option

Retrieves the value of the specified built-in or custom option.

Parameters

Parameter	Description
option_name	String value of the built-in or custom option.

Returns

Returns one of the following, depending upon the attributes defined for the option:

■	Return value of func (after execution) if a function is associated with the option

■	Default value, if one is specified for the option

■	Value of the option, as passed to the script

■	Undef if none of the above are specified

option_is_set

Checks whether an option has been explicitly set by a script or from the command line or whether the option has a default value or computed value (return value of a func).

Parameters

Parameter	Description
option_name	String value of the built-in or custom option.

Returns

Boolean. Returns 1 (true) if the option value has been explicitly set. Returns 0 (false) if the option value is a default value, is null, or has not been explicitly set. For a discussion of Boolean, see vSphere SDK for Perl Programming Conventions.

parse

Reads options from the command line, an environment variable, or a configuration file and transforms the option into appropriate data structures for validation.

Parameters

No parameters.

Returns

Returns nothing. Displays an error message and quits if the parse operation is not successful. If you want to use a configuration file, call Opts::get_config() to make sure the file can be opened. See Opts::get_config().

validate

Ensures that input values (from the command line, an environment variable, or a configuration file) are complete, consistent, and valid.

Parameters

No parameters.

Returns

Returns nothing. It displays an error message and quits if the parse operation is not successful.

usage

Displays the help text message.

Parameters

No parameters.

Returns

Returns nothing.