Class KCmdArgParser

java.lang.Object
ch.k43.util.KCmdArgParser
public class KCmdArgParser extends Object
Yet another simple command line argument parser.

The pattern to initialize the parser must be in the following format: "xyyyyz:xyyyyz": 

 Command line pattern syntax:
 
 - 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 ?
 
 Example:
 
 - ?-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
 
 Command line parsing rules:
 
 - All arguments are case sensitive
 - Short options may be combined, e.g. -la instead of -l -a
 - Short option characters are a-z, A-Z and 0-9
 - Long option names may include - (e.g. --top-header)
 - Short or long option may have a value (e.g. -n=10 or --header=none)
 - All tokens after '--' are treated as arguments to allow arguments with a starting dash, e.g. cmd -l -- -filename.txt
 
 Code example:
 
 KCmdArgParser argParser = new KCmdArgParser("?-l:?-a:!.");
 
 if (!argParser(args)) {
    System.err.println("Syntax error: " + argParser.getLastError());
    System.err.println("Usage: cmd -l -a filename");
    System.exit(1);
 }
 
 if (argParser.hasOption("-l")) {
    ...
 }
Since:
2025.09.02

  • Constructor Details

    • KCmdArgParser

      public KCmdArgParser(String argPattern)
      Initialize the parser with the syntax pattern for each valid command line argument.
      Parameters:
      argPattern - Command line pattern rule or null to prevent any argument

  • Method Details

    • getArgumentCount

      public int getArgumentCount()
      Return number of command line arguments.
      Returns:
      Number of command line arguments

    • getArguments

      public String[] getArguments()
      Return all command line arguments.
      Returns:
      Array with all command line arguments.

    • getCommandLine

      public String getCommandLine()
      Return all arguments as given in the command line (e.g. "-l -a arg1 arg2 arg3").
      Returns:
      Command line arguments separated by a blank character or null if no argument were given

    • getLastError

      public String getLastError()
      Return the last error message or null for no errors.
      Returns:
      Last error message

    • getOptionValue

      public String getOptionValue(String argOption)
      Get the passed option value.
      Parameters:
      argOption - Option name (e.g. -a or --headers)
      Returns:
      Option value or null if no value

    • getArgument

      public String getArgument()
      Return the first command line argument.
      Returns:
      First command line argument or null.

    • hasArgument

      public boolean hasArgument()
      Check if any command line argument given.
      Returns:
      True if any argument given or false

    • hasOption

      public boolean hasOption(String argOption)
      Check if the passed option is present.
      Parameters:
      argOption - Option name (e.g. -l or --headers)
      Returns:
      True if found, else otherwise

    • hasOptionValue

      public boolean hasOptionValue(String argOption)
      Check if the passed option value is present.
      Parameters:
      argOption - Option name (e.g. -l or --headers)
      Returns:
      True if found, else otherwise

    • parse

      public boolean parse(String[] argArgs)
      Parse the passed command line arguments.
      Parameters:
      argArgs - Array of Strings as passed to any main() method.
      Returns:
      True if parsing successful, false otherwise
      See Also:

    • toString

      public String toString()
      String representation of object.
      Overrides:
      toString in class Object