6argopt Module

6.1Overview

The argopt module provides measure to parse option strings in an argument list given through the command line.

Below is an example: 

import(argopt)

argopt.Parser {|p|
    p.addParam('text', 't')
    p.addFlag('test')
    p.addFlag('bold', 'b')
    try {
        [cfg, argv] = p.parse(sys.argv)
    } catch {|e|
        println(e.text)
        sys.exit(1)
    }
}
// The value of cfg['text'] is 'foo' when '--text=foo' is specified.
// The value of cfg['test'] is true when '--test' is specified.

6.2argopt.Parser Class

6.2.1Constructor

argopt.Parser() {block?}
Create an argopt.Parser instance.

6.2.2Method

argopt.Parser#parse(argv[]:string)

Parses an argument list which is usually the value of sys.argv given by sys module.

It returns the result in a format [cfg, argv] where cfg is a dict instance containing parameter values and argv a list of arguments that have not been parsed as options.

argopt.Parser#addParam(longName:string, shortName?:string, help?:string, helpValue?:string, defValue?:string)

Adds an option that comes with a value like --foo=value where foo is a long name for the option.

The argument longName specifies a long option name that follows after two hyphens in the command line. This name is also used as a key when you look for a value in the dictionary cfg returned by argopt.Parser#parse().

The argument shortName specifies a short option name that usually consists of a single character. If it exists, you can specify the option by a character followed by one hyphen like -f value where f is the short name.

The argument help and helpValue are used in a option parameter help created by argopt.Parse#formatHelp(). The string for help specifies a help text for the option while helpValue is a string printed after the equal character in the option presentation. If the argument helpValue is not specified, a string X is printed instead.

The argument defValue specifies a default value that would be used when the option is not specified in the command line.

argopt.Parser#addFlag(longName:string, shortName?:string, help?:string)

Adds an option that represents a boolean state. It comes like --foo where foo is a long name for the option.

The argument longName specifies a long option name that follows after two hyphens in the command line. This name is also used as a key when you look for a value in the dictionary cfg returned by argopt.Parser#parse().

The argument shortName specifies a short option name that usually consists of a single character. If it exists, you can specify the option by a character followed by one hyphen like -f where f is the short name.

The argument help is used in a option parameter help created by argopt.Parse#formatHelp(). The string for help specifies a help text for the option.

argopt.Parser#formatHelp(longNameFlag:boolean => true, shortNameFlag:boolean => true):[linefeed]

Creates an iterator of strings that contain help text for each option.

If the argument longNameFlag is true, the help text would contain long names.

If the argument shortNameFlag is true, the help text would contain short names.

In default, each string doesn't contain a line feed at the end. To add a line feed, specify an attribute :linefeed.

Below is an example of showing help: 

argopt.Parser {|p|
    p.addParam('text', 't', 'text value', 'txt')
    p.addFlag('flag1', 'f', 'flag option #1')
    p.addFlag('flag2', 'g', 'flag option #2')
    println(p.formatHelp())
}

The result comes as below: 

-t, --text=txt  text value
-f, --flag1     flag option #1
-g, --flag2     flag option #2