## org.apache.hadoop.util
Class Shell.ShellCommandExecutor

    java.lang.Object
      org.apache.hadoop.util.Shell
          org.apache.hadoop.util.Shell.ShellCommandExecutor

Enclosing class:
  Shell

    public static class Shell.ShellCommandExecutor

extends Shell

A simple shell command executor. `ShellCommandExecutor`should be used in cases where the output of the command needs no explicit parsing and where the command, working directory and the environment remains unchanged. The output of the command is stored as-is and is expected to be small.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.util.Shell
`Shell.ExitCodeException, Shell.ShellCommandExecutor`

Field Summary

Fields inherited from class org.apache.hadoop.util.Shell
`LOG, SET_GROUP_COMMAND, SET_OWNER_COMMAND, SET_PERMISSION_COMMAND, timeOutInterval, ULIMIT_COMMAND, USER_NAME_COMMAND, WINDOWS`

Constructor Summary
`Shell.ShellCommandExecutor(String[] execString)`
`Shell.ShellCommandExecutor(String[] execString, File dir)`
`Shell.ShellCommandExecutor(String[] execString, File dir, Map<String,String> env)`
`Shell.ShellCommandExecutor(String[] execString, File dir, Map<String,String> env, long timeout)` Create a new instance of the ShellCommandExecutor to execute a command.

Method Summary
`void` `execute()` Execute the shell command.
`protected String[]` `getExecString()` return an array containing the command name & its parameters
`String` `getOutput()` Get the output of the shell command.
`protected void` `parseExecResult(BufferedReader lines)` Parse the execution result
`String` `toString()` Returns the commands of this instance.

Methods inherited from class org.apache.hadoop.util.Shell
`execCommand, execCommand, execCommand, getExitCode, getGET_PERMISSION_COMMAND, getGroupsCommand, getGroupsForUserCommand, getProcess, getUlimitMemoryCommand, getUlimitMemoryCommand, getUsersForNetgroupCommand, isTimedOut, run, setEnvironment, setWorkingDirectory`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

Constructor Detail

### Shell.ShellCommandExecutor

    public Shell.ShellCommandExecutor(String[] execString)

### Shell.ShellCommandExecutor

    public Shell.ShellCommandExecutor(String[] execString,
                                      File dir)

### Shell.ShellCommandExecutor

    public Shell.ShellCommandExecutor(String[] execString,
                                      File dir,
                                      Map<String,String> env)

### Shell.ShellCommandExecutor

    public Shell.ShellCommandExecutor(String[] execString,
                                      File dir,
                                      Map<String,String> env,
                                      long timeout)

  Create a new instance of the ShellCommandExecutor to execute a command.

  Parameters:
    `execString` - The command to execute with arguments
    `dir` - If not-null, specifies the directory which should be set as the current working directory for the command. If null, the current working directory is not modified.
    `env` - If not-null, environment of the command will include the key-value pairs specified in the map. If null, the current environment is not modified.
    `timeout` - Specifies the time in milliseconds, after which the command will be killed and the status marked as timedout. If 0, the command will not be timed out.

Method Detail

### execute

    public void execute()
                 throws IOException

  Execute the shell command.

  Throws:
    `IOException`

### getExecString

    protected String[] getExecString()

  Description copied from class: `Shell`
  return an array containing the command name & its parameters

  Specified by:
    `getExecString` in class `Shell`

### parseExecResult

    protected void parseExecResult(BufferedReader lines)
                            throws IOException

  Description copied from class: `Shell`
  Parse the execution result

  Specified by:
    `parseExecResult` in class `Shell`
  Throws:
    `IOException`

### getOutput

    public String getOutput()

  Get the output of the shell command.

### toString

    public String toString()

  Returns the commands of this instance. Arguments with spaces in are presented with quotes round; other arguments are presented raw

  Overrides:
    `toString` in class `Object`
  Returns:
    a string representation of the object.

Copyright © 2009 The Apache Software Foundation