/*
 * Copyright 1999,2004 The Apache Software Foundation. Licensed under the
 * Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0 Unless required by applicable
 * law or agreed to in writing, software distributed under the License is
 * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.apache.catalina.ssi;


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import org.apache.catalina.util.IOTools;
/**
 * Implements the Server-side #exec command
 * 
 * @author Bip Thelin
 * @author Amy Roh
 * @author Paul Speed
 * @author Dan Sandberg
 * @version $Revision$, $Date$
 */
public class SSIExec implements SSICommand {
    protected SSIInclude ssiInclude = new SSIInclude();
    protected final static int BUFFER_SIZE = 1024;


    /**
     * @see SSICommand
     */
    public void process(SSIMediator ssiMediator, String commandName,
            String[] paramNames, String[] paramValues, PrintWriter writer) {
        String configErrMsg = ssiMediator.getConfigErrMsg();
        String paramName = paramNames[0];
        String paramValue = paramValues[0];
        String substitutedValue = ssiMediator.substituteVariables(paramValue);
        if (paramName.equalsIgnoreCase("cgi")) {
            ssiInclude.process(ssiMediator, "include",
                    new String[]{"virtual"}, new String[]{substitutedValue},
                    writer);
        } else if (paramName.equalsIgnoreCase("cmd")) {
            boolean foundProgram = false;
            try {
                Runtime rt = Runtime.getRuntime();
                Process proc = rt.exec(substitutedValue);
                foundProgram = true;
                BufferedReader stdOutReader = new BufferedReader(
                        new InputStreamReader(proc.getInputStream()));
                BufferedReader stdErrReader = new BufferedReader(
                        new InputStreamReader(proc.getErrorStream()));
                char[] buf = new char[BUFFER_SIZE];
                IOTools.flow(stdErrReader, writer, buf);
                IOTools.flow(stdOutReader, writer, buf);
                proc.waitFor();
            } catch (InterruptedException e) {
                ssiMediator.log("Couldn't exec file: " + substitutedValue, e);
                writer.write(configErrMsg);
            } catch (IOException e) {
                if (!foundProgram) {
                    //apache doesn't output an error message if it can't find
                    // a program
                }
                ssiMediator.log("Couldn't exec file: " + substitutedValue, e);
            }
        }
    }
}