edu.nmu.os.shell
Class ShellImpl

java.lang.Object
  |
  +--edu.nmu.os.shell.Shell
        |
        +--edu.nmu.os.shell.ShellImpl

All Implemented Interfaces:

java.lang.Runnable

public class ShellImpl

extends Shell

A command shell for the Java Virtual Machine

TODO: man page

Since:

jdk1.4

Version:

0.1, Jan 24, 2003 7:16:18 PM

Author:

Matt Murphy

Field Summary

static java.lang.String	CLASSPATH_PATH_PROPERTY
static java.lang.String	CLASSPATH_PWD_PROPERTY
static java.lang.String	DEFAULT_CLASSPATH_PATH
static java.lang.String	PATH_PROPERTY
static java.lang.String	PWD_PROPERTY
static java.lang.String	SHELL_LEVEL_PROPERTY
static java.lang.String	USER_PROPERTY

Fields inherited from class edu.nmu.os.shell.Shell

DEFAULT_PROMPT, GET_ERR_PERMISSION, GET_IN_PERMISSION, GET_OUT_PERMISSION, GET_PARENT_SHELL_PERMISSION, SET_SECURITY_MANAGER_PERMISSION

Constructor Summary

protected

ShellImpl(Shell s)

Method Summary

protected void	doHelp() Used as an alternate run mode for the Shell
protected void	exitMessage(java.lang.String s) Handles an exit message to be given just before the Shell exits
protected CommandLine	getCommandLine() Gets the next CommandLine to be executed
protected java.io.PrintStream	getErr0() Returns the error PrintStream of this Shell
protected java.io.InputStream	getIn0() Returns the InputStream of this Shell
protected java.util.Properties	getInitialEnv() Returns the initial values of environment variable as they should be set if this Shell has no parent
protected java.io.PrintStream	getOut0() Returns the output PrintStream of this Shell
java.lang.String	getPrompt() The user prompt
void	handleThrowable(java.lang.Throwable t) Handles the given Throwable
protected void	handleUnresolved(java.lang.String[] unresolved) Handles a list of unresolved programs
boolean	isUser() Returns whether or not the user is typing commands into this Shell
protected boolean	shouldDoHelp() Returns true if the Shell should run the doHelp() instead of running normally

Methods inherited from class edu.nmu.os.shell.Shell

executeCommand, executeCommandLine, getEnv, getEnv, getEnv, getEnv0, getEnv0, getEnv0, getErr, getIn, getOut, getParentShell, getSecurityManager, getShell, getShellLevel, isRunning, main, run, setEnv, setEnv, setEnv0, setEnv0, setSecurityManager, setSecurityManager0

Methods inherited from class java.lang.Object

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

Field Detail

SHELL_LEVEL_PROPERTY

public static final java.lang.String SHELL_LEVEL_PROPERTY

See Also:

Constant Field Values

USER_PROPERTY

public static final java.lang.String USER_PROPERTY

See Also:

Constant Field Values

PWD_PROPERTY

public static final java.lang.String PWD_PROPERTY

See Also:

Constant Field Values

PATH_PROPERTY

public static final java.lang.String PATH_PROPERTY

See Also:

Constant Field Values

CLASSPATH_PWD_PROPERTY

public static final java.lang.String CLASSPATH_PWD_PROPERTY

See Also:

Constant Field Values

CLASSPATH_PATH_PROPERTY

public static final java.lang.String CLASSPATH_PATH_PROPERTY

See Also:

Constant Field Values

DEFAULT_CLASSPATH_PATH

public static final java.lang.String DEFAULT_CLASSPATH_PATH

See Also:

Constant Field Values

Constructor Detail

ShellImpl

protected ShellImpl(Shell s)

Method Detail

shouldDoHelp

protected boolean shouldDoHelp()

Description copied from class: Shell

Returns true if the Shell should run the Shell.doHelp() instead of running normally

This method is used by Shell.main(String[])

Specified by:

shouldDoHelp in class Shell

Returns:

true if the Shell should run the Shell.doHelp(), false if it should run normally

doHelp

protected void doHelp()

Description copied from class: Shell

Used as an alternate run mode for the Shell

It is expected that this method would print some sort of help screen to the user, though that is not the required behavior.

Specified by:

doHelp in class Shell

See Also:

Shell.shouldDoHelp()

handleThrowable

public void handleThrowable(java.lang.Throwable t)

Description copied from class: Shell

Handles the given Throwable

This method handles the given Throwable in an implementation specific manner.

Specified by:

handleThrowable in class Shell

Parameters:

t - the Throwable

handleUnresolved

protected void handleUnresolved(java.lang.String[] unresolved)

Description copied from class: Shell

Handles a list of unresolved programs

This method is called when the Shell is running and the CommandLine produces unresolved programs

Specified by:

handleUnresolved in class Shell

Parameters:

unresolved - the unresolved program names

exitMessage

protected void exitMessage(java.lang.String s)

Description copied from class: Shell

Handles an exit message to be given just before the Shell exits

This method is only called during abnormal exit.

Specified by:

exitMessage in class Shell

Parameters:

s - the exit message to be handled

getInitialEnv

protected java.util.Properties getInitialEnv()

Description copied from class: Shell

Returns the initial values of environment variable as they should be set if this Shell has no parent

This method is called by the Shell.Shell(Shell) constructor to set the default environment variables of the Shell if its parent is null

Specified by:

getInitialEnv in class Shell

Returns:

the environment variables

getCommandLine

protected CommandLine getCommandLine()
                              throws ShellException

Description copied from class: Shell

Gets the next CommandLine to be executed

This method should never return null. If there are no CommandLines available, this method should either hang while it waits or throw a ShellException.

Specified by:

getCommandLine in class Shell

Returns:

the next CommandLine

Throws:

ShellException - if an error occurs

getOut0

protected java.io.PrintStream getOut0()

Description copied from class: Shell

Returns the output PrintStream of this Shell

Specified by:

getOut0 in class Shell

Returns:

the output PrintStream

getErr0

protected java.io.PrintStream getErr0()

Description copied from class: Shell

Returns the error PrintStream of this Shell

Specified by:

getErr0 in class Shell

Returns:

the error PrintStream

getIn0

protected java.io.InputStream getIn0()

Description copied from class: Shell

Returns the InputStream of this Shell

Specified by:

getIn0 in class Shell

Returns:

the InputStream

getPrompt

public java.lang.String getPrompt()

Description copied from class: Shell

The user prompt

The default implemention returns Shell.DEFAULT_PROMPT.

Overrides:

getPrompt in class Shell

Returns:

the user prompt that should be displayed while waiting for a CommandLine to be entered

isUser

public boolean isUser()

Description copied from class: Shell

Returns whether or not the user is typing commands into this Shell

Specified by:

isUser in class Shell

Returns:

true if this Shell's actor is the user, false otherwise