Source code

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.IOException;
022import java.nio.charset.StandardCharsets;
023import java.util.logging.Level;
024import java.util.logging.Logger;
025
026/**
027 * OS utils.
028 */
029public final class OSUtils {
030  private static final Logger LOG = Logger.getLogger(OSUtils.class.getName());
031
032  private OSUtils() {
033  }
034
035  /**
036   * Determines whether the current JVM is running on the Windows OS.
037   *
038   * @return true, if the JVM is running on Windows. false, otherwise
039   */
040  public static boolean isWindows() {
041    return System.getProperty("os.name").toLowerCase().contains("windows");
042  }
043
044  /**
045   * Determines whether the current JVM is running on the Unix-based OS.
046   *
047   * @return true, if the JVM is running on Linux/Mac. false, otherwise
048   */
049  public static boolean isUnix() {
050    return isLinux() || isMac();
051  }
052
053  /**
054   * Determines whether the current JVM is running on the Linux OS.
055   *
056   * @return true, if the JVM is running on Linux. false, otherwise
057   */
058  public static boolean isLinux() {
059    return System.getProperty("os.name").toLowerCase().contains("linux");
060  }
061
062  /**
063   * Determines whether the current JVM is running on the Mac OS.
064   *
065   * @return true, if the JVM is running on Mac. false, otherwise
066   */
067  public static boolean isMac() {
068    return System.getProperty("os.name").toLowerCase().contains("mac");
069  }
070
071  /**
072   * @return the process ID of the JVM, if running on Linux/Windows. This returns -1 for other OSs.
073   */
074  public static long getPID() {
075    if (isUnix()) {
076      try {
077        final Process process = new ProcessBuilder()
078            .command("bash", "-c", "echo $PPID")
079            .start();
080        final byte[] returnBytes = new byte[128];
081        if (process.getInputStream().read(returnBytes) == -1) {
082          LOG.log(Level.FINE, "No data read because end of stream was reached");
083        }
084        final Long result = Long.valueOf(new String(returnBytes, StandardCharsets.UTF_8).trim());
085        process.destroy();
086        return result;
087      } catch (final Exception e) {
088        LOG.log(Level.SEVERE, "Unable to determine PID", e);
089        return -1;
090      }
091    } else if (isWindows()) {
092      try {
093        final Process process = new ProcessBuilder()
094            .command("powershell.exe", "-NoProfile", "-Command",
095                "wmic process where processid=$pid get parentprocessid")
096            .start();
097        final byte[] returnBytes = new byte[128];
098        if (process.getInputStream().read(returnBytes) == -1) {
099          LOG.log(Level.FINE, "No data read because end of stream was reached");
100        }
101        final Long result = Long.valueOf(new String(returnBytes, StandardCharsets.UTF_8).split("\n")[1].trim());
102        process.destroy();
103        return result;
104      } catch (final Exception e) {
105        LOG.log(Level.SEVERE, "Unable to determine PID", e);
106        return -1;
107      }
108    } else {
109      return -1;
110    }
111  }
112
113  /**
114   * Kill the process.
115   *
116   * @param pid Process id
117   * @throws IOException
118   */
119  public static void kill(final long pid) throws IOException, InterruptedException {
120    if (isUnix()) {
121      final Process process = new ProcessBuilder()
122          .command("bash", "-c", "kill", "-9", String.valueOf(pid))
123          .start();
124      final int returnCode = process.waitFor();
125      LOG.fine("Kill returned: " + returnCode);
126    } else if (isWindows()) {
127      final Process process = new ProcessBuilder()
128          .command("taskkill.exe", "/f", "/pid", String.valueOf(pid))
129          .start();
130      final int returnCode = process.waitFor();
131      LOG.fine("Kill returned: " + returnCode);
132    } else {
133      throw new UnsupportedOperationException("Unable to execute kill on unknown OS");
134    }
135  }
136
137  /**
138   * Formats the given variable for expansion by Windows (<code>%VARIABLE%</code>) or Linux (<code>$VARIABLE</code>).
139   *
140   * @param variableName
141   * @return
142   */
143  public static String formatVariable(final String variableName) {
144    if (isWindows()) {
145      return "%" + variableName + "%";
146    } else {
147      return "$" + variableName;
148    }
149  }
150
151}