✂️Command Argument Parser

Define and parse command line arguments

KCmdArgParser Class Overview

• Define allowed options and arguments

• Parsing of the command line arguments

• Methods to query and retrieve options and arguments

Syntax of Parser Definition

- Multiple patterns are separated by colons  (e.g. ?-l:?-a)  
- 1st character must be be ? for an optional or ! for a required argument
- The following string is either a short or long option (e.g. -x or --xxx) or a specifies a single or multiple argument (. or ..)
- The last character can be set for an optional ? or required option value !

Examples:
- ?-l:?-a:!.  Allows optional arguments -l and -a, but requires one single argument
- ?-n?:!..    Allows the optional argument -n (with an optional value, e.g. -n or -n=10) and at least one argument
- ?--header=! Allows an optional long option. If specified, it requires an option value, e.g. --header=yes
- (empty)     Empty pattern prohibits any arguments

Example

import ch.k43.util.KCmdArgParser;

public class CmdParser {
	
   public static void main(String[] args) {

      // Parser syntax: -a and -l optional, one parameter required
      final String ARG_SYNTAX = "?-l:?-a:!.";			
		
      // Initialize command line parser with argument syntax
      KCmdArgParser argParser = new KCmdArgParser(ARG_SYNTAX);
		
      // Parse command line arguments
      if (!argParser.parse(args)) {
         System.out.println("Syntax error: " + argParser.getLastError());
         System.exit(1);
      }
		
      System.out.println("Option -l: " + argParser.hasOption("-l"));
      System.out.println("Option -a: " + argParser.hasOption("-a"));
      System.out.println("Parameter: " + argParser.getArgument());
   }
}

Output

% CmdParser -l file.txt
Option -l: true
Option -a: false
Parameter: file.txt

% CmdParser -x file.txt
Syntax error: Command line option not supported: -x