| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 freemarker.template.utility; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.InputStreamReader; |
| import java.io.Reader; |
| import java.util.List; |
| |
| import freemarker.template.TemplateModelException; |
| |
| /** |
| * <p>Gives FreeMarker the the ability to execute external commands. Will fork |
| * a process, and inline anything that process sends to stdout in the template. |
| * Based on a patch submitted by Peter Molettiere.</p> |
| * |
| * <p>BE CAREFUL! this tag, depending on use, may allow you |
| * to set something up so that users of your web |
| * application could run arbitrary code on your server. |
| * This can only happen if you allow unchecked GET/POST |
| * submissions to be used as the command string in the |
| * exec tag.</p> |
| * |
| * <p>Usage:<br> |
| * From java:</p> |
| * <pre> |
| * SimpleHash root = new SimpleHash(); |
| * |
| * root.put( "exec", new freemarker.template.utility.Execute() ); |
| * |
| * ... |
| * </pre> |
| * |
| * <p>From your FreeMarker template:</p> |
| * <pre> |
| * |
| * The following is executed: |
| * ${exec( "/usr/bin/ls" )} |
| * |
| * ... |
| * </pre> |
| */ |
| public class Execute implements freemarker.template.TemplateMethodModel { |
| |
| private final static int OUTPUT_BUFFER_SIZE = 1024; |
| |
| /** |
| * Executes a method call. |
| * |
| * @param arguments a {@code List} of {@code String} objects containing the values |
| * of the arguments passed to the method. |
| * @return the {@code TemplateModel} produced by the method, or null. |
| */ |
| @Override |
| public Object exec (List arguments) throws TemplateModelException { |
| String aExecute; |
| StringBuilder aOutputBuffer = new StringBuilder(); |
| |
| if ( arguments.size() < 1 ) { |
| throw new TemplateModelException( "Need an argument to execute" ); |
| } |
| |
| aExecute = (String) (arguments.get(0)); |
| |
| try { |
| Process exec = Runtime.getRuntime().exec( aExecute ); |
| |
| // stdout from the process comes in here |
| try (InputStream execOut = exec.getInputStream()) { |
| Reader execReader = new InputStreamReader(execOut); |
| |
| char[] buffer = new char[OUTPUT_BUFFER_SIZE]; |
| int bytes_read = execReader.read(buffer); |
| while (bytes_read > 0) { |
| aOutputBuffer.append(buffer, 0, bytes_read); |
| bytes_read = execReader.read(buffer); |
| } |
| } |
| } catch ( IOException ioe ) { |
| throw new TemplateModelException( ioe.getMessage() ); |
| } |
| return aOutputBuffer.toString(); |
| } |
| } |