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
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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
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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 
ProcessImpl()45     private ProcessImpl() {}    // Not instantiable
46 
toCString(String s)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()
start(String[] cmdarray, java.util.Map<String,String> environment, String dir, ProcessBuilder.Redirect[] redirects, boolean redirectErrorStream)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 }
148