The class provides parser of commandline options with built-in help created from a description of the options. It also provides default values for options not set on commandline.

class CmdLineOption

initialize(short_name,long_name,argument,description,default = :nil,type = :string)

short_name: short form of the option, for example "-o"

long_name: long form of the option, for example "--option"

argument

:none (option never followed by a value)
:optional
:required (option must followed by a value

description: brief description of the option that appears in the help

default: value provided to the program when the option is not set from commandline. If the option must be set by the user, use CommandLine.check_compulsory to raise error when the option is not found.

type:

:string (default)
:float
:integer

set? # => boolean

Query whether the option was set from commandline

class CommandLine

Public methods

initialize(help_on_files, *option_list)

Creates the CommandLine object from array of CmdLineOptions. The commandline is parsed, default values are used where not provided. If -h option is found, help is displayed and the program is terminated.

require_files(min, max = min)

Check commandline for required number of files.

check_compulsory(list)

Goes through array of strings (option's long_name) and terminates with error if they are not present in the commandline

file_count

Return number of files (non-option items on commandline)

set?(index) # => boolean

Query whether the option was set from commandline

Private methods

from_list(require_order, *option_list)

Fills the object with options from the list, parsing the commandline.