Java tutorial
/* * Copyright 2019 ThoughtWorks, Inc. * * Licensed 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.thoughtworks.go.utils; import org.apache.commons.lang3.StringUtils; import java.io.BufferedReader; import java.io.File; import java.io.IOException; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.regex.Matcher; import java.util.regex.Pattern; import static com.thoughtworks.go.util.ExceptionUtils.bomb; public class CommandUtils { private static final Pattern QUOTED_STRING = Pattern.compile("^(['\"]).+(\\1)$"); private static final Pattern UNESCAPED_SPACE_OR_QUOTES = Pattern.compile("(?<!\\\\)(?:\\\\{2})*[ '\"]"); private static final Pattern DOUBLE_QUOTE = Pattern.compile("(\")"); public static String exec(String... commands) { return exec(null, commands); } public static String exec(File workingDirectory, String... commands) { try { Process process = Runtime.getRuntime().exec(commands, null, workingDirectory); return captureOutput(process).toString(); } catch (Exception e) { throw bomb(e); } } private static StringBuilder captureOutput(Process process) throws IOException, InterruptedException { BufferedReader output = new BufferedReader(new InputStreamReader(process.getInputStream())); BufferedReader error = new BufferedReader(new InputStreamReader(process.getErrorStream())); StringBuilder result = new StringBuilder(); result.append("output:\n"); dump(output, result); result.append("error:\n"); dump(error, result); process.waitFor(); return result; } private static StringBuilder dump(BufferedReader reader, StringBuilder builder) throws IOException { String line; while ((line = reader.readLine()) != null) { builder.append(line + "\n"); } reader.close(); return builder; } /** * Surrounds a string with double quotes if it is not already surrounded by single or double quotes, or if it contains * unescaped spaces, single quotes, or double quotes. When surrounding with double quotes, this method will only escape * double quotes in the String. * * This method assumes the argument is well-formed if it was already surrounded by either single or double quotes. * * @param argument String to quote * @return the quoted String, if not already quoted */ public static String quoteArgument(String argument) { if (QUOTED_STRING.matcher(argument).matches() || !UNESCAPED_SPACE_OR_QUOTES.matcher(argument).find()) { // assume the argument is well-formed if it's already quoted or if there are no unescaped spaces or quotes return argument; } return String.format("\"%s\"", DOUBLE_QUOTE.matcher(argument).replaceAll(Matcher.quoteReplacement("\\") + "$1")); } public static String shellJoin(String... args) { ArrayList<String> strings = new ArrayList<>(); for (String arg : args) { strings.add(quoteArgument(arg)); } return StringUtils.join(strings, " "); } }