Java tutorial
/** * 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 com.alibaba.jstorm.utils; import java.io.IOException; import org.apache.commons.io.IOUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; public class SystemOperation { public static final Logger LOG = LoggerFactory.getLogger(SystemOperation.class); public static boolean isRoot() throws IOException { String result = SystemOperation.exec("echo $EUID").substring(0, 1); return Integer.valueOf(result.substring(0, result.length())).intValue() == 0 ? true : false; }; public static void mount(String name, String target, String type, String data) throws IOException { StringBuilder sb = new StringBuilder(); sb.append("mount -t ").append(type).append(" -o ").append(data).append(" ").append(name).append(" ") .append(target); SystemOperation.exec(sb.toString()); } public static void umount(String name) throws IOException { StringBuilder sb = new StringBuilder(); sb.append("umount ").append(name); SystemOperation.exec(sb.toString()); } public static String exec(String cmd) throws IOException { LOG.debug("Shell cmd: " + cmd); Process process = new ProcessBuilder(new String[] { "/bin/bash", "-c", cmd }).start(); try { process.waitFor(); String output = IOUtils.toString(process.getInputStream()); String errorOutput = IOUtils.toString(process.getErrorStream()); LOG.debug("Shell Output: " + output); if (errorOutput.length() != 0) { LOG.error("Shell Error Output: " + errorOutput); throw new IOException(errorOutput); } return output; } catch (InterruptedException ie) { throw new IOException(ie.toString()); } } public static void main(String[] args) throws IOException { SystemOperation.mount("test", "/cgroup/cpu", "cgroup", "cpu"); } }