Interacting with the Environment - Java - page 75

Options: Numeric: false Output: null; Inputs: -M
> java environ.GetOptDemoNew -n a b c
Options: Numeric: true Output: null; Inputs: a b c
> java environ.GetOptDemoNew -numeric a b c
Options: Numeric: true Output: null; Inputs: a b c
> java environ.GetOptDemoNew -numeric -output-file /tmp/foo a b c
Options: Numeric: true Output: /tmp/foo; Inputs: a b c

You can find a longer example exercising all the ins and outs of this version of GetOpt in the
online darwinsys-api repo under src/main/test/lang/ . The source code for GetOpt itself lives
in darwinsys-api under src/main/java/com/darwinsys/lang/GetOpt.java , and is shown in
Example 2-2 .

Example 2-2. Source code for GetOpt
// package com.darwinsys.lang;
public public class GetOpt {

/** The List of File Names found after args */
protected

class GetOpt

protected List < String > fileNameArguments ;
/** The set of characters to look for */
protected protected final final GetOptDesc [] options ;

/** Where we are in the options */
protected protected int int optind = 0 ;

/** Public constant for "no more options" */
public

public static int DONE = 0 ;

/** Internal flag - whether we are done all the options */
protected

static final final int

protected boolean false ;

/** The current option argument. */
protected

boolean done = false

protected String optarg ;

/** Retrieve the current option argument; UNIX variant spelling. */
public public String optarg () {

return return optarg ;

}
/** Retrieve the current option argument; Java variant spelling. */
public public String optArg () {

return return optarg ;

}

/** Construct a GetOpt parser, given the option specifications
* in an array of GetOptDesc objects. This is the preferred constructor.
*/
public public GetOpt ( final final GetOptDesc [] opt ) {

this this . options = opt . clone ();

}