/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Rhino code, released
* May 6, 1998.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1997-1999
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* the GNU General Public License Version 2 or later (the "GPL"), in which
* case the provisions of the GPL are applicable instead of those above. If
* you wish to allow use of your version of this file only under the terms of
* the GPL and not to allow others to use your version of this file under the
* MPL, indicate your decision by deleting the provisions above and replacing
* them with the notice and other provisions required by the GPL. If you do
* not delete the provisions above, a recipient may use your version of this
* file under either the MPL or the GPL.
*
* ***** END LICENSE BLOCK ***** */
import org.mozilla.javascript.*;
import java.io.*;
/**
* The shell program.
*
* Can execute scripts interactively or in batch mode at the command line.
* An example of controlling the JavaScript engine.
*
* @author Norris Boyd
*/
public class Shell extends ScriptableObject
{
public String getClassName()
{
return "global";
}
/**
* Main entry point.
*
* Process arguments as would a normal Java program. Also
* create a new Context and associate it with the current thread.
* Then set up the execution environment and begin to
* execute scripts.
*/
public static void main(String args[]) {
// Associate a new Context with this thread
Context cx = Context.enter();
try {
// Initialize the standard objects (Object, Function, etc.)
// This must be done before scripts can be executed.
Shell shell = new Shell();
cx.initStandardObjects(shell);
// Define some global functions particular to the shell. Note
// that these functions are not part of ECMA.
String[] names = { "print", "quit", "version", "load", "help" };
shell.defineFunctionProperties(names, Shell.class,
ScriptableObject.DONTENUM);
args = processOptions(cx, args);
// Set up "arguments" in the global scope to contain the command
// line arguments after the name of the script to execute
Object[] array;
if (args.length == 0) {
array = new Object[0];
} else {
int length = args.length - 1;
array = new Object[length];
System.arraycopy(args, 1, array, 0, length);
}
Scriptable argsObj = cx.newArray(shell, array);
shell.defineProperty("arguments", argsObj,
ScriptableObject.DONTENUM);
shell.processSource(cx, args.length == 0 ? null : args[0]);
} finally {
Context.exit();
}
}
/**
* Parse arguments.
*/
public static String[] processOptions(Context cx, String args[]) {
for (int i=0; i < args.length; i++) {
String arg = args[i];
if (!arg.startsWith("-")) {
String[] result = new String[args.length - i];
for (int j=i; j < args.length; j++)
result[j-i] = args[j];
return result;
}
if (arg.equals("-version")) {
if (++i == args.length)
usage(arg);
double d = Context.toNumber(args[i]);
if (d != d)
usage(arg);
cx.setLanguageVersion((int) d);
continue;
}
usage(arg);
}
return new String[0];
}
/**
* Print a usage message.
*/
private static void usage(String s) {
p("Didn't understand \"" + s + "\".");
p("Valid arguments are:");
p("-version 100|110|120|130|140|150|160|170");
System.exit(1);
}
/**
* Print a help message.
*
* This method is defined as a JavaScript function.
*/
public void help() {
p("");
p("Command Description");
p("======= ===========");
p("help() Display usage and help messages. ");
p("defineClass(className) Define an extension using the Java class");
p(" named with the string argument. ");
p(" Uses ScriptableObject.defineClass(). ");
p("load(['foo.js', ...]) Load JavaScript source files named by ");
p(" string arguments. ");
p("loadClass(className) Load a class named by a string argument.");
p(" The class must be a script compiled to a");
p(" class file. ");
p("print([expr ...]) Evaluate and print expressions. ");
p("quit() Quit the shell. ");
p("version([number]) Get or set the JavaScript version number.");
p("");
}
/**
* Print the string values of its arguments.
*
* This method is defined as a JavaScript function.
* Note that its arguments are of the "varargs" form, which
* allows it to handle an arbitrary number of arguments
* supplied to the JavaScript function.
*
*/
public static void print(Context cx, Scriptable thisObj,
Object[] args, Function funObj)
{
for (int i=0; i < args.length; i++) {
if (i > 0)
System.out.print(" ");
// Convert the arbitrary JavaScript value into a string form.
String s = Context.toString(args[i]);
System.out.print(s);
}
System.out.println();
}
/**
* Quit the shell.
*
* This only affects the interactive mode.
*
* This method is defined as a JavaScript function.
*/
public void quit()
{
quitting = true;
}
/**
* Get and set the language version.
*
* This method is defined as a JavaScript function.
*/
public static double version(Context cx, Scriptable thisObj,
Object[] args, Function funObj)
{
double result = cx.getLanguageVersion();
if (args.length > 0) {
double d = Context.toNumber(args[0]);
cx.setLanguageVersion((int) d);
}
return result;
}
/**
* Load and execute a set of JavaScript source files.
*
* This method is defined as a JavaScript function.
*
*/
public static void load(Context cx, Scriptable thisObj,
Object[] args, Function funObj)
{
Shell shell = (Shell)getTopLevelScope(thisObj);
for (int i = 0; i < args.length; i++) {
shell.processSource(cx, Context.toString(args[i]));
}
}
/**
* Evaluate JavaScript source.
*
* @param cx the current context
* @param filename the name of the file to compile, or null
* for interactive mode.
*/
private void processSource(Context cx, String filename)
{
if (filename == null) {
BufferedReader in = new BufferedReader
(new InputStreamReader(System.in));
String sourceName = "<stdin>";
int lineno = 1;
boolean hitEOF = false;
do {
int startline = lineno;
System.err.print("js> ");
System.err.flush();
try {
String source = "";
// Collect lines of source to compile.
while(true) {
String newline;
newline = in.readLine();
if (newline == null) {
hitEOF = true;
break;
}
source = source + newline + "\n";
lineno++;
// Continue collecting as long as more lines
// are needed to complete the current
// statement. stringIsCompilableUnit is also
// true if the source statement will result in
// any error other than one that might be
// resolved by appending more source.
if (cx.stringIsCompilableUnit(source))
break;
}
Object result = cx.evaluateString(this, source,
sourceName, startline,
null);
if (result != Context.getUndefinedValue()) {
System.err.println(Context.toString(result));
}
}
catch (WrappedException we) {
// Some form of exception was caught by JavaScript and
// propagated up.
System.err.println(we.getWrappedException().toString());
we.printStackTrace();
}
catch (EvaluatorException ee) {
// Some form of JavaScript error.
System.err.println("js: " + ee.getMessage());
}
catch (JavaScriptException jse) {
// Some form of JavaScript error.
System.err.println("js: " + jse.getMessage());
}
catch (IOException ioe) {
System.err.println(ioe.toString());
}
if (quitting) {
// The user executed the quit() function.
break;
}
} while (!hitEOF);
System.err.println();
} else {
FileReader in = null;
try {
in = new FileReader(filename);
}
catch (FileNotFoundException ex) {
Context.reportError("Couldn't open file \"" + filename + "\".");
return;
}
try {
// Here we evalute the entire contents of the file as
// a script. Text is printed only if the print() function
// is called.
cx.evaluateReader(this, in, filename, 1, null);
}
catch (WrappedException we) {
System.err.println(we.getWrappedException().toString());
we.printStackTrace();
}
catch (EvaluatorException ee) {
System.err.println("js: " + ee.getMessage());
}
catch (JavaScriptException jse) {
System.err.println("js: " + jse.getMessage());
}
catch (IOException ioe) {
System.err.println(ioe.toString());
}
finally {
try {
in.close();
}
catch (IOException ioe) {
System.err.println(ioe.toString());
}
}
}
}
private static void p(String s) {
System.out.println(s);
}
private boolean quitting;
}
