Package org.apache.hadoop.tools

Class CommandShell

java.lang.Object

org.apache.hadoop.conf.Configured

org.apache.hadoop.tools.CommandShell

All Implemented Interfaces:

Configurable, Tool

Direct Known Subclasses:

CredentialShell, DtUtilShell, KeyShell

public abstract class CommandShell
extends Configured
implements Tool

This program is a CLI utility base class utilizing hadoop Tool class.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected class	CommandShell.SubCommand	Base class for any subcommands of this shell command.

Constructor Summary

Constructors

Constructor	Description
CommandShell()

Method Summary

Modifier and Type	Method	Description
abstract String	getCommandUsage()	Return usage string for the command including any summary of subcommands.
PrintStream	getErr()
PrintStream	getOut()
protected abstract int	init(String[] args)	Parse the command line arguments and initialize subcommand instance.
protected void	printException(Exception ex)
protected final void	printShellUsage()
int	run(String[] args)	Execute the command with the given arguments.
void	setErr(PrintStream p)
void	setOut(PrintStream p)
void	setSubCommand(CommandShell.SubCommand cmd)

Methods inherited from class org.apache.hadoop.conf.Configured

getConf, setConf

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.hadoop.conf.Configurable

getConf, setConf

Constructor Details

CommandShell

public CommandShell()

Method Details

getCommandUsage

public abstract String getCommandUsage()

Return usage string for the command including any summary of subcommands.

Returns:

command usage.

setSubCommand

public void setSubCommand(CommandShell.SubCommand cmd)

setOut

public void setOut(PrintStream p)

getOut

public PrintStream getOut()

setErr

public void setErr(PrintStream p)

getErr

public PrintStream getErr()

run

public int run(String[] args)
        throws Exception

Description copied from interface: Tool

Execute the command with the given arguments.

Specified by:

run in interface Tool

Parameters:

args - command specific arguments.

Returns:

exit code.

Throws:

Exception - command exception.

init

protected abstract int init(String[] args)
                     throws Exception

Parse the command line arguments and initialize subcommand instance.

Parameters:

args - arguments.

Returns:

0 if the argument(s) were recognized, 1 otherwise

Throws:

Exception - init exception.

printShellUsage

protected final void printShellUsage()

printException

protected void printException(Exception ex)