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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.maven.properties.internal;
20  
21  import java.util.Locale;
22  import java.util.Map;
23  import java.util.Properties;
24  
25  import org.apache.maven.utils.Os;
26  
27  /**
28   * Assists the project builder. <strong>Warning:</strong> This is an internal utility class that is only public for
29   * technical reasons, it is not part of the public API. In particular, this class can be changed or deleted without
30   * prior notice.
31   *
32   * @since 3.0
33   */
34  public class EnvironmentUtils {
35  
36      private static Properties envVars;
37  
38      /**
39       * Adds the environment variables in the form of properties whose keys are prefixed with {@code env.}, e.g. {@code
40       * env.PATH}. Unlike native environment variables, properties are always case-sensitive. For the sake of
41       * determinism, the environment variable names will be normalized to upper case on platforms with case-insensitive
42       * variable lookup.
43       *
44       * @param props The properties to add the environment variables to, may be {@code null}.
45       */
46      public static void addEnvVars(Properties props) {
47          if (props != null) {
48              if (envVars == null) {
49                  Properties tmp = new Properties();
50                  boolean caseSensitive = !Os.IS_WINDOWS;
51                  for (Map.Entry<String, String> entry : System.getenv().entrySet()) {
52                      String key = "env."
53                              + (caseSensitive ? entry.getKey() : entry.getKey().toUpperCase(Locale.ENGLISH));
54                      tmp.setProperty(key, entry.getValue());
55                  }
56                  envVars = tmp;
57              }
58  
59              props.putAll(envVars);
60          }
61      }
62  }