1 /* 2 * Copyright 2016 Google LLC 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.cloud.testing; 18 19 import java.io.File; 20 import java.io.IOException; 21 import java.nio.file.Path; 22 import java.util.ArrayList; 23 import java.util.List; 24 25 /** Utility class that executes system commands on both Windows and Unix. */ 26 class CommandWrapper { 27 28 private final List<String> prefix; 29 private List<String> command; 30 private String nullFilename; 31 private boolean redirectOutputToNull; 32 private boolean redirectErrorStream; 33 private boolean redirectErrorInherit; 34 private Path directory; 35 CommandWrapper()36 private CommandWrapper() { 37 this.prefix = new ArrayList<>(); 38 if (BaseEmulatorHelper.isWindows()) { 39 this.prefix.add("cmd"); 40 this.prefix.add("/C"); 41 this.nullFilename = "NUL:"; 42 } else { 43 this.prefix.add("bash"); 44 this.nullFilename = "/dev/null"; 45 } 46 } 47 setCommand(List<String> command)48 CommandWrapper setCommand(List<String> command) { 49 this.command = new ArrayList<>(command.size() + this.prefix.size()); 50 this.command.addAll(prefix); 51 this.command.addAll(command); 52 return this; 53 } 54 setRedirectOutputToNull()55 CommandWrapper setRedirectOutputToNull() { 56 this.redirectOutputToNull = true; 57 return this; 58 } 59 setRedirectErrorStream()60 CommandWrapper setRedirectErrorStream() { 61 this.redirectErrorStream = true; 62 return this; 63 } 64 setRedirectErrorInherit()65 CommandWrapper setRedirectErrorInherit() { 66 this.redirectErrorInherit = true; 67 return this; 68 } 69 setDirectory(Path directory)70 CommandWrapper setDirectory(Path directory) { 71 this.directory = directory; 72 return this; 73 } 74 getBuilder()75 ProcessBuilder getBuilder() { 76 ProcessBuilder builder = new ProcessBuilder(command); 77 if (redirectOutputToNull) { 78 builder.redirectOutput(new File(nullFilename)); 79 } 80 if (directory != null) { 81 builder.directory(directory.toFile()); 82 } 83 if (redirectErrorStream) { 84 builder.redirectErrorStream(true); 85 } 86 if (redirectErrorInherit) { 87 builder.redirectError(ProcessBuilder.Redirect.INHERIT); 88 } 89 return builder; 90 } 91 start()92 public Process start() throws IOException { 93 return getBuilder().start(); 94 } 95 create()96 static CommandWrapper create() { 97 return new CommandWrapper(); 98 } 99 } 100