001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.reef.util;
020
021import java.io.BufferedReader;
022import java.io.IOException;
023import java.io.InputStreamReader;
024import java.nio.charset.StandardCharsets;
025import java.util.logging.Level;
026import java.util.logging.Logger;
027
028/**
029 * run given command and return the result as string.
030 */
031public final class CommandUtils {
032  /**
033   * Standard java logger.
034   */
035  private static final Logger LOG = Logger.getLogger(CommandUtils.class.getName());
036
037  public static String runCommand(final String command) {
038    final StringBuilder sb = new StringBuilder();
039    try {
040      final String cmd = OSUtils.isWindows() ? "cmd.exe /c " + command : command;
041      final Process proc = Runtime.getRuntime().exec(cmd);
042
043      try (final BufferedReader input =
044               new BufferedReader(new InputStreamReader(proc.getInputStream(), StandardCharsets.UTF_8))) {
045        String line;
046        while ((line = input.readLine()) != null) {
047          sb.append(line).append('\n');
048        }
049      }
050    } catch (final IOException ex) {
051      LOG.log(Level.SEVERE, "Error in call: " + command, ex);
052      sb.append(ex);
053    }
054    return sb.toString();
055  }
056
057  /**
058   * Empty private constructor to prohibit instantiation of utility class.
059   */
060  private CommandUtils() {
061  }
062}