Start splitting into maven modules

13 files changed, 1612 insertions, 0 deletions

diff --git a/base/src/main/java/bjc/utils/cli/CLICommander.java b/base/src/main/java/bjc/utils/cli/CLICommander.java
new file mode 100644
index 0000000..cccb255
--- /dev/null
+++ b/base/src/main/java/bjc/utils/cli/CLICommander.java
@@ -0,0 +1,134 @@
+package bjc.utils.cli;
+
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.PrintStream;
+import java.util.Arrays;
+import java.util.Scanner;
+
+/**
+ * Runs a CLI interface from the provided set of streams.
+ *
+ * @author ben
+ *
+ */
+public class CLICommander {
+	/*
+	 * The streams used for input and normal/error output.
+	 */
+	private final InputStream	input;
+	private final OutputStream	output;
+	private final OutputStream	error;
+
+	/*
+	 * The command mode to start execution in.
+	 */
+	private CommandMode initialMode;
+
+	/**
+	 * Create a new CLI interface powered by streams.
+	 *
+	 * @param input
+	 *                The stream to get user input from.
+	 * @param output
+	 *                The stream to send normal output to.
+	 * @param error
+	 *                The stream to send error output to.
+	 */
+	public CLICommander(final InputStream input, final OutputStream output, final OutputStream error) {
+		if (input == null)
+			throw new NullPointerException("Input stream must not be null");
+		else if (output == null)
+			throw new NullPointerException("Output stream must not be null");
+		else if (error == null) throw new NullPointerException("Error stream must not be null");
+
+		this.input = input;
+		this.output = output;
+		this.error = error;
+	}
+
+	/**
+	 * Start handling commands from the given input stream.
+	 */
+	public void runCommands() {
+		/*
+		 * Setup output streams.
+		 */
+		final PrintStream normalOutput = new PrintStream(output);
+		final PrintStream errorOutput = new PrintStream(error);
+
+		/*
+		 * Set up input streams.
+		 *
+		 * We're suppressing the warning because we might use the input
+		 * stream multiple times.
+		 */
+		@SuppressWarnings("resource")
+		final Scanner inputSource = new Scanner(input);
+
+		/*
+		 * The mode currently being used to handle commands.
+		 *
+		 * Used to preserve the initial mode.
+		 */
+		CommandMode currentMode = initialMode;
+
+		/*
+		 * Process commands until we're told to stop.
+		 */
+		while (currentMode != null) {
+			/*
+			 * Print out the command prompt, using a custom prompt
+			 * if one is specified.
+			 */
+			if (currentMode.isCustomPromptEnabled()) {
+				normalOutput.print(currentMode.getCustomPrompt());
+			} else {
+				normalOutput.print(currentMode.getName() + ">> ");
+			}
+
+			/*
+			 * Read in a command.
+			 */
+			final String currentLine = inputSource.nextLine();
+
+			/*
+			 * Handle commands we can handle.
+			 */
+			if (currentMode.canHandle(currentLine)) {
+				final String[] commandTokens = currentLine.split(" ");
+				String[] commandArgs = null;
+
+				final int argCount = commandTokens.length;
+
+				/*
+				 * Parse args if they are present.
+				 */
+				if (argCount > 1) {
+					commandArgs = Arrays.copyOfRange(commandTokens, 1, argCount);
+				}
+
+				/*
+				 * Process command.
+				 */
+				currentMode = currentMode.process(commandTokens[0], commandArgs);
+			} else {
+				errorOutput.print("Error: Unrecognized command " + currentLine);
+			}
+		}
+
+		normalOutput.print("Exiting now.");
+	}
+
+	/**
+	 * Set the initial command mode to use.
+	 *
+	 * @param initialMode
+	 *                The initial command mode to use.
+	 */
+	public void setInitialCommandMode(final CommandMode initialMode) {
+		if (initialMode == null) throw new NullPointerException("Initial mode must be non-zero");
+
+		this.initialMode = initialMode;
+	}
+}
diff --git a/base/src/main/java/bjc/utils/cli/Command.java b/base/src/main/java/bjc/utils/cli/Command.java
new file mode 100644
index 0000000..02bc061
--- /dev/null
+++ b/base/src/main/java/bjc/utils/cli/Command.java
@@ -0,0 +1,39 @@
+package bjc.utils.cli;
+
+/**
+ * Represents a command that can be invoked from a {@link CommandMode}
+ *
+ * @author ben
+ *
+ */
+public interface Command {
+	/**
+	 * Create a command that serves as an alias to this one
+	 *
+	 * @return A command that serves as an alias to this one
+	 */
+	Command aliased();
+
+	/**
+	 * Get the handler that executes this command
+	 *
+	 * @return The handler that executes this command
+	 */
+	CommandHandler getHandler();
+
+	/**
+	 * Get the help entry for this command
+	 *
+	 * @return The help entry for this command
+	 */
+	CommandHelp getHelp();
+
+	/**
+	 * Check if this command is an alias of another command
+	 *
+	 * @return Whether or not this command is an alias of another
+	 */
+	default boolean isAlias() {
+		return false;
+	}
+}
diff --git a/base/src/main/java/bjc/utils/cli/CommandHandler.java b/base/src/main/java/bjc/utils/cli/CommandHandler.java
new file mode 100644
index 0000000..2548248
--- /dev/null
+++ b/base/src/main/java/bjc/utils/cli/CommandHandler.java
@@ -0,0 +1,24 @@
+package bjc.utils.cli;
+
+import java.util.function.Function;
+
+/**
+ * A handler for a command
+ *
+ * @author ben
+ *
+ */
+@FunctionalInterface
+public interface CommandHandler extends Function<String[], CommandMode> {
+	/**
+	 * Execute this command
+	 *
+	 * @param args
+	 *                The arguments for this command
+	 * @return The command mode to switch to after this command, or null to
+	 *         stop executing commands
+	 */
+	default CommandMode handle(final String[] args) {
+		return this.apply(args);
+	}
+}
diff --git a/base/src/main/java/bjc/utils/cli/CommandHelp.java b/base/src/main/java/bjc/utils/cli/CommandHelp.java
new file mode 100644
index 0000000..86567a0
--- /dev/null
+++ b/base/src/main/java/bjc/utils/cli/CommandHelp.java
@@ -0,0 +1,31 @@
+package bjc.utils.cli;
+
+/**
+ * Interface for the help entry for a command
+ *
+ * @author ben
+ *
+ */
+public interface CommandHelp {
+	/**
+	 * Get the description of a command.
+	 *
+	 * @return The description of a command
+	 */
+	String getDescription();
+
+	/**
+	 * Get the summary line for a command.
+	 *
+	 * A summary line should consist of a string of the following format
+	 * 
+	 * <pre>
+	 * "&lt;command-name>\t&lt;command-summary>"
+	 * </pre>
+	 * 
+	 * where anything in angle brackets should be filled in.
+	 *
+	 * @return The summary line line for a command
+	 */
+	String getSummary();
+}
diff --git a/base/src/main/java/bjc/utils/cli/CommandMode.java b/base/src/main/java/bjc/utils/cli/CommandMode.java
new file mode 100644
index 0000000..39c72fc
--- /dev/null
+++ b/base/src/main/java/bjc/utils/cli/CommandMode.java
@@ -0,0 +1,72 @@
+package bjc.utils.cli;
+
+/**
+ * A mode for determining the commands that are valid to enter, and then
+ * handling those commands
+ *
+ * @author ben
+ *
+ */
+public interface CommandMode extends Comparable<CommandMode> {
+	/**
+	 * Check to see if this mode can handle the specified command
+	 *
+	 * @param command
+	 *                The command to check
+	 * @return Whether or not this mode can handle the command. It is
+	 *         assumed not by default
+	 */
+	default boolean canHandle(final String command) {
+		return false;
+	};
+
+	/**
+	 * Get the custom prompt for this mode
+	 *
+	 * @return the custom prompt for this mode
+	 *
+	 * @throws UnsupportedOperationException
+	 *                 if this mode doesn't support a custom prompt
+	 */
+	default String getCustomPrompt() {
+		throw new UnsupportedOperationException("This mode doesn't support a custom prompt");
+	}
+
+	/**
+	 * Get the name of this command mode
+	 *
+	 * @return The name of this command mode, which is the empty string by
+	 *         default
+	 */
+	public default String getName() {
+		return "";
+	}
+
+	/**
+	 * Check if this mode uses a custom prompt
+	 *
+	 * @return Whether or not this mode uses a custom prompt
+	 */
+	default boolean isCustomPromptEnabled() {
+		return false;
+	}
+
+	/**
+	 * Process a command in this mode
+	 *
+	 * @param command
+	 *                The command to process
+	 * @param args
+	 *                A list of arguments to the command
+	 * @return The command mode to use for the next command. Defaults to
+	 *         returning this, and doing nothing else
+	 */
+	default CommandMode process(final String command, final String[] args) {
+		return this;
+	}
+
+	@Override
+	default int compareTo(final CommandMode o) {
+		return getName().compareTo(o.getName());
+	}
+}
diff --git a/base/src/main/java/bjc/utils/cli/DelegatingCommand.java b/base/src/main/java/bjc/utils/cli/DelegatingCommand.java
new file mode 100644
index 0000000..acaa3a6
--- /dev/null
+++ b/base/src/main/java/bjc/utils/cli/DelegatingCommand.java
@@ -0,0 +1,64 @@
+package bjc.utils.cli;
+
+/**
+ * A class for a command that delegates to another command.
+ *
+ * @author ben
+ *
+ */
+class DelegatingCommand implements Command {
+	/*
+	 * The command to delegate to.
+	 */
+	private final Command delegate;
+
+	/**
+	 * Create a new command that delegates to another command.
+	 *
+	 * @param delegate
+	 *                The command to delegate to.
+	 */
+	public DelegatingCommand(final Command delegate) {
+		this.delegate = delegate;
+	}
+
+	@Override
+	public Command aliased() {
+		return new DelegatingCommand(delegate);
+	}
+
+	@Override
+	public CommandHandler getHandler() {
+		return delegate.getHandler();
+	}
+
+	@Override
+	public CommandHelp getHelp() {
+		return delegate.getHelp();
+	}
+
+	@Override
+	public boolean isAlias() {
+		return true;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 *
+	 * @see java.lang.Object#toString()
+	 */
+	@Override
+	public String toString() {
+		final StringBuilder builder = new StringBuilder();
+		builder.append("DelegatingCommand [");
+
+		if (delegate != null) {
+			builder.append("delegate=");
+			builder.append(delegate);
+		}
+
+		builder.append("]");
+
+		return builder.toString();
+	}
+}
diff --git a/base/src/main/java/bjc/utils/cli/GenericCommand.java b/base/src/main/java/bjc/utils/cli/GenericCommand.java
new file mode 100644
index 0000000..4ae4dea
--- /dev/null
+++ b/base/src/main/java/bjc/utils/cli/GenericCommand.java
@@ -0,0 +1,84 @@
+package bjc.utils.cli;
+
+/**
+ * Generic command implementation.
+ *
+ * @author ben
+ *
+ */
+public class GenericCommand implements Command {
+	/*
+	 * The behavior for invoking the command.
+	 */
+	private final CommandHandler handler;
+
+	/*
+	 * The help for the command.
+	 */
+	private CommandHelp help;
+
+	/**
+	 * Create a new generic command.
+	 *
+	 * @param handler
+	 *                The handler to use for the command.
+	 * @param description
+	 *                The description of the command. May be null, in which
+	 *                case a default is provided.
+	 * @param help
+	 *                The detailed help message for the command. May be
+	 *                null, in which case the description is repeated for
+	 *                the detailed help.
+	 */
+	public GenericCommand(final CommandHandler handler, final String description, final String help) {
+		if (handler == null) throw new NullPointerException("Command handler must not be null");
+
+		this.handler = handler;
+
+		if (description == null) {
+			this.help = new NullHelp();
+		} else {
+			this.help = new GenericHelp(description, help);
+		}
+	}
+
+	@Override
+	public Command aliased() {
+		return new DelegatingCommand(this);
+	}
+
+	@Override
+	public CommandHandler getHandler() {
+		return handler;
+	}
+
+	@Override
+	public CommandHelp getHelp() {
+		return help;
+	}
+
+	@Override
+	public boolean isAlias() {
+		return false;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 *
+	 * @see java.lang.Object#toString()
+	 */
+	@Override
+	public String toString() {
+		final StringBuilder builder = new StringBuilder();
+		builder.append("GenericCommand [");
+
+		if (help != null) {
+			builder.append("help=");
+			builder.append(help);
+		}
+
+		builder.append("]");
+
+		return builder.toString();
+	}
+}
diff --git a/base/src/main/java/bjc/utils/cli/GenericCommandMode.java b/base/src/main/java/bjc/utils/cli/GenericCommandMode.java
new file mode 100644
index 0000000..8764537
--- /dev/null
+++ b/base/src/main/java/bjc/utils/cli/GenericCommandMode.java
@@ -0,0 +1,469 @@
+package bjc.utils.cli;
+
+import java.util.TreeMap;
+import java.util.function.BiConsumer;
+import java.util.function.Consumer;
+
+import bjc.utils.funcdata.FunctionalMap;
+import bjc.utils.funcdata.IMap;
+
+/**
+ * A general command mode, with a customizable set of commands
+ *
+ * There is a small set of commands which is handled by default. The first is
+ * 'list', which lists all the commands the user can input. The second is
+ * 'alias', which allows the user to bind a new name to a command
+ *
+ * @author ben
+ *
+ */
+public class GenericCommandMode implements CommandMode {
+	/*
+	 * Contains the commands this mode handles
+	 */
+	private final IMap<String, Command>	commandHandlers;
+	private final IMap<String, Command>	defaultHandlers;
+
+	/*
+	 * Contains help topics without an associated command
+	 */
+	private final IMap<String, CommandHelp> helpTopics;
+
+	/*
+	 * The action to execute upon encountering an unknown command
+	 */
+	private BiConsumer<String, String[]> unknownCommandHandler;
+
+	/*
+	 * The functions to use for input/output
+	 */
+	private final Consumer<String>	errorOutput;
+	private final Consumer<String>	normalOutput;
+
+	/*
+	 * The name of this command mode, or null if it is unnamed
+	 */
+	private String modeName;
+
+	/*
+	 * The custom prompt to use, or null if none is specified
+	 */
+	private String customPrompt;
+
+	/**
+	 * Create a new generic command mode
+	 *
+	 * @param normalOutput
+	 *                The function to use for normal output
+	 * @param errorOutput
+	 *                The function to use for error output
+	 */
+	public GenericCommandMode(final Consumer<String> normalOutput, final Consumer<String> errorOutput) {
+		if (normalOutput == null)
+			throw new NullPointerException("Normal output source must be non-null");
+		else if (errorOutput == null) throw new NullPointerException("Error output source must be non-null");
+
+		this.normalOutput = normalOutput;
+		this.errorOutput = errorOutput;
+
+		/*
+		 * Initialize handler maps so that they sort in alphabetical
+		 */
+		/*
+		 * order
+		 */
+		commandHandlers = new FunctionalMap<>(new TreeMap<>());
+		defaultHandlers = new FunctionalMap<>(new TreeMap<>());
+		helpTopics = new FunctionalMap<>(new TreeMap<>());
+
+		setupDefaultCommands();
+	}
+
+	/**
+	 * Add an alias to an existing command
+	 *
+	 * @param commandName
+	 *                The name of the command to add an alias for
+	 * @param aliasName
+	 *                The new alias for the command
+	 *
+	 * @throws IllegalArgumentException
+	 *                 if the specified command doesn't have a bound
+	 *                 handler, or if the alias name already has a bound
+	 *                 value
+	 */
+	public void addCommandAlias(final String commandName, final String aliasName) {
+		if (commandName == null)
+			throw new NullPointerException("Command name must not be null");
+		else if (aliasName == null)
+			throw new NullPointerException("Alias name must not be null");
+		else if (!commandHandlers.containsKey(commandName) && !defaultHandlers.containsKey(commandName))
+			throw new IllegalArgumentException("Cannot alias non-existant command '" + commandName + "'");
+		else if (commandHandlers.containsKey(aliasName) || defaultHandlers.containsKey(aliasName))
+			throw new IllegalArgumentException(
+					"Cannot bind alias '" + aliasName + "' to a command with a bound handler");
+		else {
+			Command aliasedCommand;
+
+			if (defaultHandlers.containsKey(commandName)) {
+				aliasedCommand = defaultHandlers.get(commandName).aliased();
+			} else {
+				aliasedCommand = commandHandlers.get(commandName).aliased();
+			}
+
+			commandHandlers.put(aliasName, aliasedCommand);
+		}
+	}
+
+	/**
+	 * Add a command to this command mode
+	 *
+	 * @param command
+	 *                The name of the command to add
+	 * @param handler
+	 *                The handler to use for the specified command
+	 *
+	 * @throws IllegalArgumentException
+	 *                 if the specified command already has a handler
+	 *                 registered
+	 */
+	public void addCommandHandler(final String command, final Command handler) {
+		if (command == null)
+			throw new NullPointerException("Command must not be null");
+		else if (handler == null)
+			throw new NullPointerException("Handler must not be null");
+		else if (canHandle(command))
+			throw new IllegalArgumentException("Command " + command + " already has a handler registered");
+		else {
+			commandHandlers.put(command, handler);
+		}
+	}
+
+	/**
+	 * Add a help topic to this command mode that isn't tied to a command
+	 *
+	 * @param topicName
+	 *                The name of the topic
+	 * @param topic
+	 *                The contents of the topic
+	 */
+	public void addHelpTopic(final String topicName, final CommandHelp topic) {
+		helpTopics.put(topicName, topic);
+	}
+
+	/*
+	 * Default command builders
+	 */
+
+	private GenericCommand buildAliasCommand() {
+		final String aliasShortHelp = "alias\tAlias one command to another";
+		final String aliasLongHelp = "Gives a command another name it can be invoked by."
+				+ " Invoke with two arguments: the name of the command to alias"
+				+ "followed by the name of the alias to give that command.";
+
+		return new GenericCommand((args) -> {
+			doAliasCommands(args);
+
+			return this;
+		}, aliasShortHelp, aliasLongHelp);
+	}
+
+	private GenericCommand buildClearCommands() {
+		final String clearShortHelp = "clear\tClear the screen";
+		final String clearLongHelp = "Clears the screen of all the text on it," + " and prints a new prompt.";
+
+		return new GenericCommand((args) -> {
+			errorOutput.accept("ERROR: This console doesn't support screen clearing");
+
+			return this;
+		}, clearShortHelp, clearLongHelp);
+	}
+
+	private GenericCommand buildExitCommand() {
+		final String exitShortHelp = "exit\tExit the console";
+		final String exitLongHelp = "First prompts the user to make sure they want to"
+				+ " exit, then quits if they say they do";
+
+		return new GenericCommand((args) -> {
+			errorOutput.accept("ERROR: This console doesn't support auto-exiting");
+
+			return this;
+		}, exitShortHelp, exitLongHelp);
+	}
+
+	private GenericCommand buildHelpCommand() {
+		final String helpShortHelp = "help\tConsult the help system";
+		final String helpLongHelp = "Consults the internal help system."
+				+ " Invoked in two different ways. Invoking with no arguments"
+				+ " causes all the topics you can ask for details on to be list,"
+				+ " while invoking with the name of a topic will print the entry" + " for that topic";
+
+		return new GenericCommand((args) -> {
+			if (args == null || args.length == 0) {
+				/*
+				 * Invoke general help
+				 */
+				doHelpSummary();
+			} else {
+				/*
+				 * Invoke help for a command
+				 */
+				doHelpCommand(args[0]);
+			}
+
+			return this;
+		}, helpShortHelp, helpLongHelp);
+	}
+
+	private GenericCommand buildListCommand() {
+		final String listShortHelp = "list\tList available commands";
+		final String listLongHelp = "Lists all of the commands available in this mode,"
+				+ " as well as commands available in any mode";
+
+		return new GenericCommand((args) -> {
+			doListCommands();
+
+			return this;
+		}, listShortHelp, listLongHelp);
+	}
+
+	@Override
+	public boolean canHandle(final String command) {
+		return commandHandlers.containsKey(command) || defaultHandlers.containsKey(command);
+	}
+
+	/*
+	 * Implement default commands
+	 */
+
+	private void doAliasCommands(final String[] args) {
+		if (args.length != 2) {
+			errorOutput.accept("ERROR: Alias requires two arguments."
+					+ " The command name, and the alias for that command");
+		} else {
+			final String commandName = args[0];
+			final String aliasName = args[1];
+
+			if (!canHandle(commandName)) {
+				errorOutput.accept("ERROR: '" + commandName + "' is not a valid command.");
+			} else if (canHandle(aliasName)) {
+				errorOutput.accept("ERROR: Cannot overwrite command '" + aliasName + "'");
+			} else {
+				addCommandAlias(commandName, aliasName);
+			}
+		}
+	}
+
+	private void doHelpCommand(final String commandName) {
+		if (commandHandlers.containsKey(commandName)) {
+			final String desc = commandHandlers.get(commandName).getHelp().getDescription();
+
+			normalOutput.accept("\n" + desc);
+		} else if (defaultHandlers.containsKey(commandName)) {
+			final String desc = defaultHandlers.get(commandName).getHelp().getDescription();
+
+			normalOutput.accept("\n" + desc);
+		} else if (helpTopics.containsKey(commandName)) {
+			normalOutput.accept("\n" + helpTopics.get(commandName).getDescription());
+		} else {
+			errorOutput.accept(
+					"ERROR: I'm sorry, but there is no help available for '" + commandName + "'");
+		}
+	}
+
+	private void doHelpSummary() {
+		normalOutput.accept("Help topics for this command mode are as follows:\n");
+
+		if (commandHandlers.size() > 0) {
+			commandHandlers.forEachValue(command -> {
+				if (!command.isAlias()) {
+					normalOutput.accept("\t" + command.getHelp().getSummary() + "\n");
+				}
+			});
+		} else {
+			normalOutput.accept("\tNone available\n");
+		}
+
+		normalOutput.accept("\nHelp topics available in all command modes are as follows\n");
+		if (defaultHandlers.size() > 0) {
+			defaultHandlers.forEachValue(command -> {
+				if (!command.isAlias()) {
+					normalOutput.accept("\t" + command.getHelp().getSummary() + "\n");
+				}
+			});
+		} else {
+			normalOutput.accept("\tNone available\n");
+		}
+
+		normalOutput.accept("\nHelp topics not associated with a command are as follows\n");
+		if (helpTopics.size() > 0) {
+			helpTopics.forEachValue(topic -> {
+				normalOutput.accept("\t" + topic.getSummary() + "\n");
+			});
+		} else {
+			normalOutput.accept("\tNone available\n");
+		}
+	}
+
+	private void doListCommands() {
+		normalOutput.accept("The available commands for this mode are as follows:\n");
+
+		commandHandlers.keyList().forEach(commandName -> {
+			normalOutput.accept("\t" + commandName);
+		});
+
+		normalOutput.accept("\nThe following commands are available in all modes:\n");
+		defaultHandlers.keyList().forEach(commandName -> {
+			normalOutput.accept("\t" + commandName);
+		});
+
+		normalOutput.accept("\n");
+	}
+
+	@Override
+	public String getCustomPrompt() {
+		if (customPrompt != null) return customPrompt;
+
+		return CommandMode.super.getCustomPrompt();
+	}
+
+	@Override
+	public String getName() {
+		if (modeName != null) return modeName;
+
+		return CommandMode.super.getName();
+	}
+
+	@Override
+	public boolean isCustomPromptEnabled() {
+		return customPrompt != null;
+	}
+
+	@Override
+	public CommandMode process(final String command, final String[] args) {
+		normalOutput.accept("\n");
+
+		if (defaultHandlers.containsKey(command))
+			return defaultHandlers.get(command).getHandler().handle(args);
+		else if (commandHandlers.containsKey(command))
+			return commandHandlers.get(command).getHandler().handle(args);
+		else {
+			if (args != null) {
+				errorOutput.accept("ERROR: Unrecognized command " + command + String.join(" ", args));
+			} else {
+				errorOutput.accept("ERROR: Unrecognized command " + command);
+			}
+
+			if (unknownCommandHandler == null)
+				throw new UnsupportedOperationException("Command " + command + " is invalid.");
+
+			unknownCommandHandler.accept(command, args);
+		}
+
+		return this;
+	}
+
+	/**
+	 * Set the custom prompt for this mode
+	 *
+	 * @param prompt
+	 *                The custom prompt for this mode, or null to disable
+	 *                the custom prompt
+	 */
+	public void setCustomPrompt(final String prompt) {
+		customPrompt = prompt;
+	}
+
+	/**
+	 * Set the name of this mode
+	 *
+	 * @param name
+	 *                The desired name of this mode, or null to use the
+	 *                default name
+	 */
+	public void setModeName(final String name) {
+		modeName = name;
+	}
+
+	/**
+	 * Set the handler to use for unknown commands
+	 *
+	 * @param handler
+	 *                The handler to use for unknown commands, or null to
+	 *                throw on unknown commands
+	 */
+	public void setUnknownCommandHandler(final BiConsumer<String, String[]> handler) {
+		if (handler == null) throw new NullPointerException("Handler must not be null");
+
+		unknownCommandHandler = handler;
+	}
+
+	private void setupDefaultCommands() {
+		defaultHandlers.put("list", buildListCommand());
+		defaultHandlers.put("alias", buildAliasCommand());
+		defaultHandlers.put("help", buildHelpCommand());
+
+		addCommandAlias("help", "man");
+
+		/*
+		 * Add commands handled in a upper layer.
+		 */
+
+		/*
+		 * @TODO figure out a place to put commands that apply across
+		 */
+		/*
+		 * all
+		 */
+		/*
+		 * modes, but only apply to a specific application
+		 */
+		defaultHandlers.put("clear", buildClearCommands());
+		defaultHandlers.put("exit", buildExitCommand());
+	}
+
+	/*
+	 * (non-Javadoc)
+	 *
+	 * @see java.lang.Object#toString()
+	 */
+	@Override
+	public String toString() {
+		final StringBuilder builder = new StringBuilder();
+		builder.append("GenericCommandMode [");
+
+		if (commandHandlers != null) {
+			builder.append("commandHandlers=");
+			builder.append(commandHandlers);
+		}
+
+		if (defaultHandlers != null) {
+			builder.append(", ");
+			builder.append("defaultHandlers=");
+			builder.append(defaultHandlers);
+		}
+
+		if (helpTopics != null) {
+			builder.append(", ");
+			builder.append("helpTopics=");
+			builder.append(helpTopics);
+		}
+
+		if (modeName != null) {
+			builder.append(", ");
+			builder.append("modeName=");
+			builder.append(modeName);
+		}
+
+		if (customPrompt != null) {
+			builder.append(", ");
+			builder.append("customPrompt=");
+			builder.append(customPrompt);
+		}
+
+		builder.append("]");
+
+		return builder.toString();
+	}
+
+}
diff --git a/base/src/main/java/bjc/utils/cli/GenericHelp.java b/base/src/main/java/bjc/utils/cli/GenericHelp.java
new file mode 100644
index 0000000..38adf57
--- /dev/null
+++ b/base/src/main/java/bjc/utils/cli/GenericHelp.java
@@ -0,0 +1,63 @@
+package bjc.utils.cli;
+
+/**
+ * Generic implementation of a help topic
+ *
+ * @author ben
+ *
+ */
+public class GenericHelp implements CommandHelp {
+	// The strings for this help topic
+	private final String	summary;
+	private final String	description;
+
+	/**
+	 * Create a new help topic
+	 *
+	 * @param summary
+	 *                The summary of this help topic
+	 * @param description
+	 *                The description of this help topic, or null if this
+	 *                help topic doesn't have a more detailed description
+	 */
+	public GenericHelp(final String summary, final String description) {
+		if (summary == null) throw new NullPointerException("Help summary must be non-null");
+
+		this.summary = summary;
+		this.description = description;
+	}
+
+	@Override
+	public String getDescription() {
+		if (description == null) return summary;
+
+		return description;
+	}
+
+	@Override
+	public String getSummary() {
+		return summary;
+	}
+
+	@Override
+	public String toString() {
+		final StringBuilder builder = new StringBuilder();
+
+		builder.append("GenericHelp [");
+
+		if (summary != null) {
+			builder.append("summary=");
+			builder.append(summary);
+		}
+
+		if (description != null) {
+			builder.append(", ");
+			builder.append("description=");
+			builder.append(description);
+		}
+
+		builder.append("]");
+
+		return builder.toString();
+	}
+}
diff --git a/base/src/main/java/bjc/utils/cli/NullHelp.java b/base/src/main/java/bjc/utils/cli/NullHelp.java
new file mode 100644
index 0000000..6c49ae6
--- /dev/null
+++ b/base/src/main/java/bjc/utils/cli/NullHelp.java
@@ -0,0 +1,20 @@
+package bjc.utils.cli;
+
+/**
+ * Implementation of a help topic that doesn't exist
+ *
+ * @author ben
+ *
+ */
+public class NullHelp implements CommandHelp {
+	@Override
+	public String getDescription() {
+		return "No description provided";
+	}
+
+	@Override
+	public String getSummary() {
+		return "No summary provided";
+	}
+
+}
diff --git a/base/src/main/java/bjc/utils/cli/objects/BlockReaderCLI.java b/base/src/main/java/bjc/utils/cli/objects/BlockReaderCLI.java
new file mode 100644
index 0000000..ec66fe2
--- /dev/null
+++ b/base/src/main/java/bjc/utils/cli/objects/BlockReaderCLI.java
@@ -0,0 +1,392 @@
+package bjc.utils.cli.objects;
+
+import java.io.InputStreamReader;
+import java.io.Reader;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Scanner;
+import java.util.function.Predicate;
+import java.util.logging.Logger;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.regex.PatternSyntaxException;
+
+import bjc.utils.ioutils.Prompter;
+import bjc.utils.ioutils.blocks.*;
+
+import static bjc.utils.cli.objects.Command.CommandStatus;
+import static bjc.utils.cli.objects.Command.CommandStatus.*;
+
+public class BlockReaderCLI {
+	private final Logger LOGGER = Logger.getLogger(BlockReaderCLI.class.getName());
+
+	public static class BlockReaderState {
+		public final Map<String, BlockReader> readers;
+		public final Map<String, Reader>      sources;
+
+		public BlockReaderState(Map<String, BlockReader> readers, Map<String, Reader> sources) {
+			this.readers = readers;
+			this.sources = sources;
+		}
+	}
+
+	private BlockReaderState stat;
+
+	/**
+	 * Create a new CLI for configuring BlockReaders.
+	 *
+	 * @param srcs
+	 * 	The container of initial I/O sources.
+	 */
+	public BlockReaderCLI(Map<String, Reader> srcs) {
+		stat = new BlockReaderState(new HashMap<>(), srcs);
+	}
+
+	public static void main(String[] args) {
+		/*
+		 * Create/configure I/O sources.
+		 */
+		Map<String, Reader> sources = new HashMap<>();
+		sources.put("stdio", new InputStreamReader(System.in));
+
+		BlockReaderCLI reader = new BlockReaderCLI(sources);
+
+		reader.run(new Scanner(System.in), "console", true);
+	}
+
+	/**
+	 * Run the CLI on an input source.
+	 *
+	 * @param input
+	 * 	The place to read input from.
+	 * @param ioSource
+	 * 	The name of the place to read input from.
+	 * @param interactive
+	 *	Whether or not the source is interactive
+	 */
+	public void run(Scanner input, String ioSource, boolean interactive) {
+		int lno = 0;
+		while(input.hasNextLine()) {
+			if(interactive)
+				System.out.printf("reader-conf(%d)>", lno);
+
+			String ln = input.nextLine();
+
+			lno += 1;
+
+			Command com = Command.fromString(ln, lno, ioSource);
+			if(com == null) continue;
+
+			CommandStatus stat = handleCommand(com, interactive);
+			if(stat == FINISH || stat == ERROR) {
+				return;
+			}
+		}
+
+		input.close();
+	}
+
+	/*
+	 * Handle a command.
+	 */
+	public CommandStatus handleCommand(Command com, boolean interactive) {
+		switch(com.nameCommand) {
+		case "def-filtered":
+			return defFiltered(com);
+		case "def-layered":
+			return defLayered(com);
+		case "def-pushback":
+			return defPushback(com);
+		case "def-simple":
+			return defSimple(com);
+		case "def-serial":
+			return defSerial(com);
+		case "def-toggled":
+			return defToggled(com);
+		case "}":
+		case "end":
+		case "exit":
+		case "quit":
+			if(interactive)
+				System.out.printf("Exiting reader-conf, %d readers configured in %d commands\n",
+						stat.readers.size(), com.lineNo);
+			return FINISH;
+		default:
+			LOGGER.severe(com.error("Unknown command '%s'\n", com.nameCommand));
+			return FAIL;
+		}
+	}
+
+	private CommandStatus defFiltered(Command com) {
+		String remn = com.remnCommand;
+
+		/*
+		 * Get the block name.
+		 */
+		int idx = remn.indexOf(' ');
+		if(idx == -1) {
+			LOGGER.severe(com.error("No name argument for def-filtered.\n"));
+			return FAIL;
+		}
+		String blockName = remn.substring(0, idx).trim();
+		remn             = remn.substring(idx).trim();
+
+		/*
+		 * Check there isn't a reader already bound to this name.
+		 */
+		if(stat.readers.containsKey(blockName)) {
+			LOGGER.warning(com.warn("Shadowing existing reader named %s\n", blockName));
+		}
+
+		/*
+		 * Get the reader name.
+		 */
+		idx = remn.indexOf(' ');
+		if(idx == -1) {
+			LOGGER.severe(com.error("No reader-name argument for def-filtered.\n"));	
+			return FAIL;
+		}
+		String readerName = remn.substring(0, idx).trim();
+		remn              = remn.substring(idx).trim();
+
+		/*
+		 * Check there is a reader bound to that name.
+		 */
+		if(!stat.readers.containsKey(readerName)) {
+			LOGGER.severe(com.error("No source named %s\n", readerName));
+			return FAIL;
+		}
+
+		/*
+		 * Get the pattern.
+		 */
+		if(remn.equals("")) {
+			LOGGER.severe(com.error("No filter argument for def-filtered\n"));
+			return FAIL;
+		}
+
+		String filter = remn;
+
+		try {
+			Pattern pat = Pattern.compile(filter);
+
+			Predicate<Block> pred = (block) -> {
+				Matcher mat = pat.matcher(block.contents);
+
+				return mat.matches();
+			};
+
+			BlockReader reader = new FilteredBlockReader(stat.readers.get(readerName), pred);
+
+			stat.readers.put(blockName, reader);
+		} catch (PatternSyntaxException psex) {
+			LOGGER.severe(com.error("Invalid regular expression '%s' for filter. (%s)\n", filter, psex.getMessage()));
+			return FAIL;
+		}
+
+		return SUCCESS;
+	}
+
+	private CommandStatus defPushback(Command com) {
+		String[] parts = com.remnCommand.split(" ");
+
+		if(parts.length != 2) {
+			LOGGER.severe(com.error("Incorrect number of arguments to def-pushback. Requires a block name and a reader name\n"));
+			return FAIL;
+		}
+
+		String blockName = parts[0];
+		if(stat.readers.containsKey(blockName)) {
+			LOGGER.warning(com.warn("Shadowing existing reader %s\n", blockName));
+			return FAIL;
+		}
+
+		String readerName = parts[1];
+		if(!stat.readers.containsKey(readerName)) {
+			LOGGER.severe(com.error("No reader named %s\n", readerName));
+			return FAIL;
+		}
+
+		BlockReader reader = new PushbackBlockReader(stat.readers.get(readerName));
+		stat.readers.put(blockName, reader);
+
+		return SUCCESS;
+	}
+
+	private CommandStatus defToggled(Command com) {
+		String[] parts = com.remnCommand.split(" ");
+
+		if(parts.length != 3) {
+			LOGGER.severe(com.error("Incorrect number of arguments to def-toggled. Requires a block name and two reader names\n"));
+			return FAIL;
+		}
+
+		/*
+		 * Get the block name.
+		 */
+		String blockName = parts[0];
+		if(stat.readers.containsKey(blockName)) {
+			LOGGER.warning(com.warn("Shadowing existing reader named %s\n", blockName));
+		}
+
+		/*
+		 * Make sure the component readers exist.
+		 */
+		if(!stat.readers.containsKey(parts[1])) {
+			LOGGER.severe(com.error("No reader named %s\n", parts[1]));
+			return FAIL;
+		}
+
+		if(!stat.readers.containsKey(parts[2])) {
+			LOGGER.severe(com.error("No reader named %s\n", parts[2]));
+			return FAIL;
+		}
+
+		BlockReader reader = new ToggledBlockReader(stat.readers.get(parts[1]), stat.readers.get(parts[2]));
+		stat.readers.put(blockName, reader);
+
+		return SUCCESS;
+	}
+
+	private CommandStatus defLayered(Command com) {
+		String[] parts = com.remnCommand.split(" ");
+
+		if(parts.length != 3) {
+			LOGGER.severe(com.error("Incorrect number of arguments to def-layered. Requires a block name and two reader names\n"));
+			return FAIL;
+		}
+
+		/*
+		 * Get the block name.
+		 */
+		String blockName = parts[0];
+		if(stat.readers.containsKey(blockName)) {
+			LOGGER.warning(com.warn("Shadowing existing reader named %s\n", blockName));
+		}
+
+		/*
+		 * Make sure the component readers exist.
+		 */
+		if(!stat.readers.containsKey(parts[1])) {
+			LOGGER.severe(com.error("No reader named %s\n", parts[1]));
+			return FAIL;
+		}
+
+		if(!stat.readers.containsKey(parts[2])) {
+			LOGGER.severe(com.error("No reader named %s\n", parts[2]));
+			return FAIL;
+		}
+
+		BlockReader reader = new LayeredBlockReader(stat.readers.get(parts[1]), stat.readers.get(parts[2]));
+		stat.readers.put(blockName, reader);
+
+		return SUCCESS;
+	}
+
+	private CommandStatus defSerial(Command com) {
+		String[] parts = com.remnCommand.split(" ");
+
+		if(parts.length < 2) {
+			LOGGER.severe(com.error("Not enough arguments to def-serial. Requires at least a block name and at least one reader name\n"));
+			return FAIL;
+		}
+
+		/*
+		 * Get the name for this BlockReader.
+		 */
+		String blockName = parts[0];
+		/*
+		 * Check there isn't a reader already bound to this name.
+		 */
+		if(stat.readers.containsKey(blockName)) {
+			LOGGER.warning(com.warn("Shadowing existing reader named %s\n", blockName));
+		}
+
+		/*
+		 * Get all of the component readers.
+		 */
+		BlockReader[] readerArr = new BlockReader[parts.length - 1];
+		for(int i = 1; i < parts.length; i++) {
+			String readerName = parts[i];
+
+			/*
+			 * Check there is a reader bound to that name.
+			 */
+			if(!stat.readers.containsKey(readerName)) {
+				LOGGER.severe(com.error("No reader named %s\n", readerName));
+				return FAIL;
+			}
+
+			readerArr[i] = stat.readers.get(readerName);
+		}
+
+		BlockReader reader = new SerialBlockReader(readerArr);
+
+		stat.readers.put(blockName, reader);
+
+		return SUCCESS;
+	}
+
+	private CommandStatus defSimple(Command com) {
+		String remn = com.remnCommand;
+
+		/*
+		 * Get the block name.
+		 */
+		int idx = remn.indexOf(' ');
+		if(idx == -1) {
+			LOGGER.severe(com.error("No name argument for def-simple.\n"));
+			return FAIL;
+		}
+		String blockName = remn.substring(0, idx).trim();
+		remn             = remn.substring(idx).trim();
+
+		/*
+		 * Check there isn't a reader already bound to this name.
+		 */
+		if(stat.readers.containsKey(blockName)) {
+			LOGGER.warning(com.warn("Shadowing existing reader named %s\n", blockName));
+		}
+
+		/*
+		 * Get the source name.
+		 */
+		idx = remn.indexOf(' ');
+		if(idx == -1) {
+			LOGGER.severe(com.error("No source-name argument for def-simple.\n"));	
+			return FAIL;
+		}
+		String sourceName = remn.substring(0, idx).trim();
+		remn              = remn.substring(idx).trim();
+
+		/*
+		 * Check there is a source bound to that name.
+		 */
+		if(!stat.sources.containsKey(sourceName)) {
+			LOGGER.severe(com.error("No source named %s\n", sourceName));
+			return FAIL;
+		}
+
+		/*
+		 * Get the pattern.
+		 */
+		if(remn.equals("")) {
+			LOGGER.severe(com.error("No delimiter argument for def-simple\n"));
+			return FAIL;
+		}
+
+		String delim = remn;
+
+		try {
+			BlockReader reader = new SimpleBlockReader(delim, stat.sources.get(sourceName));
+
+			stat.readers.put(blockName, reader);
+		} catch (PatternSyntaxException psex) {
+			LOGGER.severe(com.error("Invalid regular expression '%s' for delimiter. (%s)\n", delim, psex.getMessage()));
+			return FAIL;
+		}
+
+		return SUCCESS;
+	}
+}
diff --git a/base/src/main/java/bjc/utils/cli/objects/Command.java b/base/src/main/java/bjc/utils/cli/objects/Command.java
new file mode 100644
index 0000000..e605a2b
--- /dev/null
+++ b/base/src/main/java/bjc/utils/cli/objects/Command.java
@@ -0,0 +1,87 @@
+package bjc.utils.cli.objects;
+
+public class Command {
+	/**
+	 * Command status values.
+	 */
+	public static enum CommandStatus {
+		/**
+		 * The command succeded.
+		 */
+		SUCCESS,
+		/**
+		 * The command failed non-fatally.
+		 */
+		FAIL,
+		/**
+		 * The command failed fatally.
+		 */
+		ERROR,
+		/**
+		 * The command was the last one.
+		 */
+		FINISH,
+	}
+
+	public final int lineNo;
+
+	public final String fullCommand;
+	public final String remnCommand;
+	public final String nameCommand;
+
+	public final String ioSource;
+
+	/**
+	 * Create a new command.
+	 *
+	 * @param ln
+	 * 	The line to get the command from.
+	 * @param lno
+	 * 	The number of the line the command came from.
+	 * @param ioSrc
+	 * 	The name of where the I/O came from.
+	 */
+	public Command(String ln, int lno, String ioSrc) {
+		int idx = ln.indexOf(' ');
+
+		if(idx == -1) idx = ln.length();
+
+		fullCommand = ln;
+		nameCommand = ln.substring(0, idx).trim();
+		remnCommand = ln.substring(idx).trim();
+
+		lineNo = lno;
+
+		ioSource = ioSrc;
+	}
+
+	public static Command fromString(String ln, int lno, String ioSource) {
+		/*
+		 * Ignore blank lines and comments.
+		 */
+		if(ln.equals(""))      return null;
+		if(ln.startsWith("#")) return null;
+
+		/*
+		 * Trim off comments part-way through the line.
+		 */
+		int idxHash = ln.indexOf('#');
+		if(idxHash != -1) {
+			ln = ln.substring(0, idxHash).trim();
+		}
+
+		return new Command(ln, lno, ioSource);
+	}
+
+	public String warn(String warning, Object... parms) {
+		String msg = String.format(warning, parms);
+
+		return String.format("WARNING (%s:%d): %s", ioSource, lineNo, msg);
+	}
+
+	public String error(String err, Object... parms) {
+		String msg = String.format(err, parms);
+
+		return String.format("ERROR (%s:%d): %s", ioSource, lineNo, msg);
+	}
+}
diff --git a/base/src/main/java/bjc/utils/cli/objects/DefineCLI.java b/base/src/main/java/bjc/utils/cli/objects/DefineCLI.java
new file mode 100644
index 0000000..bb2733f
--- /dev/null
+++ b/base/src/main/java/bjc/utils/cli/objects/DefineCLI.java
@@ -0,0 +1,133 @@
+package bjc.utils.cli.objects;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Scanner;
+import java.util.function.UnaryOperator;
+import java.util.logging.Logger;
+import java.util.regex.Pattern;
+
+import static bjc.utils.cli.objects.Command.CommandStatus;
+import static bjc.utils.cli.objects.Command.CommandStatus.*;
+
+public class DefineCLI {
+	private final Logger LOGGER = Logger.getLogger(DefineCLI.class.getName());
+
+	public static class DefineState {
+		public final Map<String, UnaryOperator<String>> defines;
+
+		public final Map<String, String> strings;
+		public final Map<String, String> formats;
+
+		public final Map<String, Pattern> patterns;
+
+		public DefineState() {
+			this(new HashMap<>(), new HashMap<>(), new HashMap<>(), new HashMap<>());
+		}
+
+		public DefineState(Map<String, UnaryOperator<String>> defines,
+				Map<String, String> strings, Map<String, String> formats,
+				Map<String, Pattern> patterns) {
+			this.defines = defines;
+
+			this.strings = strings;
+			this.formats = formats;
+
+			this.patterns = patterns;
+		}
+	}
+
+	private DefineState stat;
+
+	public DefineCLI() {
+		stat = new DefineState();
+	}
+
+	public static void main(String[] args) {
+		DefineCLI defin = new DefineCLI();
+	}
+
+	/**
+	 * Run the CLI on an input source.
+	 *
+	 * @param input
+	 * 	The place to read input from.
+	 * @param ioSource
+	 * 	The name of the place to read input from.
+	 * @param interactive
+	 *	Whether or not the source is interactive
+	 */
+	public void run(Scanner input, String ioSource, boolean interactive) {
+		int lno = 0;
+		while(input.hasNextLine()) {
+			if(interactive)
+				System.out.printf("define-conf(%d)>", lno);
+
+			String ln = input.nextLine();
+
+			lno += 1;
+
+			Command com = Command.fromString(ln, lno, ioSource);
+			if(com == null) continue;
+
+			handleCommand(com, interactive);
+		}
+
+		input.close();
+	}
+
+	public void handleCommand(Command com, boolean interactive) {
+		switch(com.nameCommand) {
+		case "def-string":
+		default:
+			LOGGER.severe(com.error("Unknown command %s\n", com.nameCommand));
+			break;
+		}
+	}
+
+	private CommandStatus defString(Command com) {
+		String remn = com.remnCommand;
+
+		int idx = remn.indexOf(' ');
+		if(idx == -1) {
+			LOGGER.warning(com.warn("Binding empty string to name '%s'\n", remn));
+			idx = remn.length();
+		}
+		String name = remn.substring(0, idx);
+		String strang = remn.substring(idx);
+
+		if(stat.strings.containsKey(name)) {
+			LOGGER.warning(com.warn("Shadowing string '%s'\n", name));
+		}
+
+		stat.strings.put(name, strang);
+
+		return SUCCESS;
+	}
+
+	private CommandStatus defFormat(Command com) {
+		String remn = com.remnCommand;
+
+		int idx = remn.indexOf(' ');
+		if(idx == -1) {
+			LOGGER.warning(com.warn("Binding empty format to name '%s'\n", remn));
+			idx = remn.length();
+		}
+		String name = remn.substring(0, idx);
+		String fmt = remn.substring(idx);
+
+		if(stat.formats.containsKey(name)) {
+			LOGGER.warning(com.warn("Shadowing format '%s'\n", name));
+		}
+
+		stat.formats.put(name, fmt);
+
+		return SUCCESS;
+	}
+
+	private CommandStatus bindFormat(Command com) {
+		String[] parts = com.remnCommand.split(" ");
+
+		return SUCCESS;
+	}
+}