Improve compatibility with lua 5.2.

src/jse/org/luaj/vm2/lib/jse/JseOsLib.java

@@ -24,6 +24,7 @@ import java.io.File;
 import java.io.IOException;
 
 import org.luaj.vm2.LuaValue;
+import org.luaj.vm2.Varargs;
 import org.luaj.vm2.lib.LibFunction;
 
 /**
@@ -79,23 +80,20 @@ public class JseOsLib extends org.luaj.vm2.lib.OsLib {
 	public JseOsLib() {
 	}
 
-	protected int execute(String command) {
-		Runtime r = Runtime.getRuntime();
+	protected Varargs execute(String command) {
+		int exitValue;
 		try {
-			final Process p = r.exec(command);
-			try {
-				p.waitFor();
-				return p.exitValue();
-			} finally {
-				p.destroy();
-			}
+			exitValue = new JseProcess(command, null, globals.STDOUT, globals.STDERR).waitFor();
 		} catch (IOException ioe) {
-			return EXEC_IOEXCEPTION;
+			exitValue = EXEC_IOEXCEPTION;
 		} catch (InterruptedException e) {
-			return EXEC_INTERRUPTED;
+			exitValue = EXEC_INTERRUPTED;
 		} catch (Throwable t) {
-			return EXEC_ERROR;
-		}		
+			exitValue = EXEC_ERROR;
+		}
+		if (exitValue == 0)
+			return varargsOf(TRUE, valueOf("exit"), ZERO);
+		return varargsOf(NIL, valueOf("signal"), valueOf(exitValue));
 	}
 
 	protected void remove(String filename) throws IOException {

src/jse/org/luaj/vm2/lib/jse/JseProcess.java

@@ -0,0 +1,116 @@
+/*******************************************************************************
+* Copyright (c) 2012 Luaj.org. All rights reserved.
+*
+* Permission is hereby granted, free of charge, to any person obtaining a copy
+* of this software and associated documentation files (the "Software"), to deal
+* in the Software without restriction, including without limitation the rights
+* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+* copies of the Software, and to permit persons to whom the Software is
+* furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included in
+* all copies or substantial portions of the Software.
+* 
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+* THE SOFTWARE.
+******************************************************************************/
+package org.luaj.vm2.lib.jse;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+/** Analog of Process that pipes input and output to client-specified streams.
+ */
+public class JseProcess {
+
+	final Process process;
+	final Thread input,output,error;
+
+	/** Construct a process around a command, with specified streams to redirect input and output to.
+	 * 
+	 * @param cmd The command to execute, including arguments, if any
+	 * @param stdin Optional InputStream to read from as process input, or null if input is not needed.
+	 * @param stdout Optional OutputStream to copy process output to, or null if output is ignored.
+	 * @param stderr Optinoal OutputStream to copy process stderr output to, or null if output is ignored.
+	 * @throws IOException If the system process could not be created.
+	 * @see Process
+	 */
+	public JseProcess(String[] cmd, InputStream stdin, OutputStream stdout, OutputStream stderr) throws IOException {
+		this(Runtime.getRuntime().exec(cmd), stdin, stdout, stderr);	
+	}
+
+	/** Construct a process around a command, with specified streams to redirect input and output to.
+	 * 
+	 * @param cmd The command to execute, including arguments, if any
+	 * @param stdin Optional InputStream to read from as process input, or null if input is not needed.
+	 * @param stdout Optional OutputStream to copy process output to, or null if output is ignored.
+	 * @param stderr Optinoal OutputStream to copy process stderr output to, or null if output is ignored.
+	 * @throws IOException If the system process could not be created.
+	 * @see Process
+	 */
+	public JseProcess(String cmd, InputStream stdin, OutputStream stdout, OutputStream stderr) throws IOException {
+		this(Runtime.getRuntime().exec(cmd), stdin, stdout, stderr);	
+	}
+
+	private JseProcess(Process process, InputStream stdin, OutputStream stdout, OutputStream stderr) {
+		this.process = process;
+		input = stdin == null? null: copyBytes(stdin, process.getOutputStream(), null, process.getOutputStream());
+		output = stdout == null? null: copyBytes(process.getInputStream(), stdout, process.getInputStream(), null);
+		error = stderr == null? null: copyBytes(process.getErrorStream(), stderr, process.getErrorStream(), null);
+	}
+
+	/** Get the exit value of the process. */
+	public int exitValue() {
+		return process.exitValue();
+	}
+
+	/** Wait for the process to complete, and all pending output to finish.
+	 * @return The exit status.
+	 * @throws InterruptedException
+	 */
+	public int waitFor() throws InterruptedException {
+		int r = process.waitFor();
+		if (input != null)
+			input.join();
+		if (output != null)
+			output.join();
+		if (error != null)
+			error.join();
+		process.destroy();
+		return r;
+	}
+
+	/** Create a thread to copy bytes from input to output. */
+	private Thread copyBytes(final InputStream input,
+			final OutputStream output, final InputStream ownedInput,
+			final OutputStream ownedOutput) {
+		Thread t = (new Thread() {
+			public void run() {
+				try {
+					byte[] buf = new byte[1024];
+					int r;
+					try {
+						while ((r = input.read(buf)) >= 0) {
+							output.write(buf, 0, r);
+						}
+					} finally {
+						if (ownedInput != null)
+							ownedInput.close();
+						if (ownedOutput != null)
+							ownedOutput.close();
+					}
+				} catch (IOException e) {
+					e.printStackTrace();
+				}
+			}
+		});
+		t.start();
+		return t;
+	}
+}