1   /*
2    * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
6    * under the terms of the GNU General Public License version 2 only, as
7    * published by the Free Software Foundation.  Oracle designates this
8    * particular file as subject to the "Classpath" exception as provided
9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
16   *
17   * You should have received a copy of the GNU General Public License version
18   * 2 along with this work; if not, write to the Free Software Foundation,
19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20   *
21   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22   * or visit www.oracle.com if you need additional information or have any
23   * questions.
24   */
25  
26  package java.lang;
27  
28  import java.io.IOException;
29  import java.io.FileInputStream;
30  import java.io.FileOutputStream;
31  import java.lang.ProcessBuilder.Redirect;
32  import java.lang.ProcessBuilder.Redirect;
33  
34  /**
35   * This class is for the exclusive use of ProcessBuilder.start() to
36   * create new processes.
37   *
38   * @author Martin Buchholz
39   * @since   1.5
40   */
41  final class ProcessImpl {
42      private static final sun.misc.JavaIOFileDescriptorAccess fdAccess
43          = sun.misc.SharedSecrets.getJavaIOFileDescriptorAccess();
44  
45      private ProcessImpl() {}    // Not instantiable
46  
47      private static byte[] toCString(String s) {
48          if (s == null)
49              return null;
50          byte[] bytes = s.getBytes();
51          byte[] result = new byte[bytes.length + 1];
52          System.arraycopy(bytes, 0,
53                           result, 0,
54                           bytes.length);
55          result[result.length-1] = (byte)0;
56          return result;
57      }
58  
59      // Only for use by ProcessBuilder.start()
60      static Process start(String[] cmdarray,
61                           java.util.Map<String,String> environment,
62                           String dir,
63                           ProcessBuilder.Redirect[] redirects,
64                           boolean redirectErrorStream)
65          throws IOException
66      {
67          assert cmdarray != null && cmdarray.length > 0;
68  
69          // Convert arguments to a contiguous block; it's easier to do
70          // memory management in Java than in C.
71          byte[][] args = new byte[cmdarray.length-1][];
72          int size = args.length; // For added NUL bytes
73          for (int i = 0; i < args.length; i++) {
74              args[i] = cmdarray[i+1].getBytes();
75              size += args[i].length;
76          }
77          byte[] argBlock = new byte[size];
78          int i = 0;
79          for (byte[] arg : args) {
80              System.arraycopy(arg, 0, argBlock, i, arg.length);
81              i += arg.length + 1;
82              // No need to write NUL bytes explicitly
83          }
84  
85          int[] envc = new int[1];
86          byte[] envBlock = ProcessEnvironment.toEnvironmentBlock(environment, envc);
87  
88          int[] std_fds;
89  
90          FileInputStream  f0 = null;
91          FileOutputStream f1 = null;
92          FileOutputStream f2 = null;
93  
94          try {
95              if (redirects == null) {
96                  std_fds = new int[] { -1, -1, -1 };
97              } else {
98                  std_fds = new int[3];
99  
100                 if (redirects[0] == Redirect.PIPE)
101                     std_fds[0] = -1;
102                 else if (redirects[0] == Redirect.INHERIT)
103                     std_fds[0] = 0;
104                 else {
105                     f0 = new FileInputStream(redirects[0].file());
106                     std_fds[0] = fdAccess.get(f0.getFD());
107                 }
108 
109                 if (redirects[1] == Redirect.PIPE)
110                     std_fds[1] = -1;
111                 else if (redirects[1] == Redirect.INHERIT)
112                     std_fds[1] = 1;
113                 else {
114                     f1 = new FileOutputStream(redirects[1].file(),
115                                               redirects[1].append());
116                     std_fds[1] = fdAccess.get(f1.getFD());
117                 }
118 
119                 if (redirects[2] == Redirect.PIPE)
120                     std_fds[2] = -1;
121                 else if (redirects[2] == Redirect.INHERIT)
122                     std_fds[2] = 2;
123                 else {
124                     f2 = new FileOutputStream(redirects[2].file(),
125                                               redirects[2].append());
126                     std_fds[2] = fdAccess.get(f2.getFD());
127                 }
128             }
129 
130         return new UNIXProcess
131             (toCString(cmdarray[0]),
132              argBlock, args.length,
133              envBlock, envc[0],
134              toCString(dir),
135                  std_fds,
136              redirectErrorStream);
137         } finally {
138             // In theory, close() can throw IOException
139             // (although it is rather unlikely to happen here)
140             try { if (f0 != null) f0.close(); }
141             finally {
142                 try { if (f1 != null) f1.close(); }
143                 finally { if (f2 != null) f2.close(); }
144             }
145         }
146     }
147 }