@CliCommand(value = PREFIX + "du", help = "Displays sizes of files and directories contained in the given directory or the length of a file in case its just a file")
	public void du(
			@CliOption(key = { "", "dir" }, mandatory = false, unspecifiedDefaultValue = ".", help = "directory to be listed") final String path,
			@CliOption(key = { "summary" }, mandatory = false, specifiedDefaultValue = TRUE, unspecifiedDefaultValue = FALSE, help = "whether with summary") final boolean summary) {
		List<String> argv = new ArrayList<String>();
		if (summary) {
			argv.add("-dus");
		}
		else {
			argv.add("-du");
		}
		argv.add(path);
		run(argv.toArray(new String[0]));
	}
HDFS shell commands

@author Jarred Li
@author Glenn Renfro
spring-xd-shell/src/main/java/org/springframework/xd/shell/hadoop/FsShellCommands.java