org.apache.hadoop.fs
Class ShellCommand

java.lang.Object
  org.apache.hadoop.fs.ShellCommand

Direct Known Subclasses:

DF, DU

public abstract class ShellCommand
extends Object

A base class for running a unix command like du or df

Method Summary

static String	execCommand(String[] cmd) Static method to execute a command.
protected abstract String[]	getExecString() return an array comtaining the command name & its parameters
protected abstract void	parseExecResult(BufferedReader lines) Parse the execution result
protected void	run() check to see if a command needs to be execuated

Methods inherited from class java.lang.Object

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

Method Detail

run

protected void run()
            throws IOException

check to see if a command needs to be execuated

Throws:

IOException

getExecString

protected abstract String[] getExecString()

return an array comtaining the command name & its parameters

parseExecResult

protected abstract void parseExecResult(BufferedReader lines)
                                 throws IOException

Parse the execution result

Throws:

IOException

execCommand

public static String execCommand(String[] cmd)
                          throws IOException

Static method to execute a command. Covers most of the simple cases without requiring the user to implement Command interface.

Throws:

IOException