1 /*
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3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * version 2 for more details (a copy is included in the LICENSE file that
13  * accompanied this code).
14  *
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24 
25 package sun.jvm.hotspot.utilities;
26 
27 import java.io.*;
28 import java.nio.charset.Charset;
29 import java.util.*;
30 
31 import sun.jvm.hotspot.debugger.*;
32 
33 /** A utility class encapsulating useful operations on C strings
34     represented as Addresses */
35 
36 public class CStringUtilities {
37   /** Return the length of a null-terminated ASCII string in the
38       remote process */
getStringLength(Address addr)39   public static int getStringLength(Address addr) {
40     int i = 0;
41     while (addr.getCIntegerAt(i, 1, false) != 0) {
42       i++;
43     }
44     return i;
45   }
46 
47   private static String encoding = System.getProperty("file.encoding", "US-ASCII");
48 
getString(Address addr)49   public static String getString(Address addr) {
50     return getString(addr, Charset.forName(encoding));
51   }
52 
53   /** Fetch a null-terminated ASCII string from the remote process.
54       Returns null if the argument is null, otherwise returns a
55       non-null string (for example, returns an empty string if the
56       first character fetched is the null terminator). */
getString(Address addr, Charset charset)57   public static String getString(Address addr, Charset charset) {
58     if (addr == null) {
59       return null;
60     }
61 
62     List data = new ArrayList();
63     byte val = 0;
64     long i = 0;
65     do {
66       val = (byte) addr.getCIntegerAt(i, 1, false);
67       if (val != 0) {
68         data.add(new Byte(val));
69       }
70       ++i;
71     } while (val != 0);
72 
73     // Convert to byte[] and from there to String
74     byte[] bytes = new byte[data.size()];
75     for (i = 0; i < data.size(); ++i) {
76       bytes[(int) i] = ((Byte) data.get((int) i)).byteValue();
77     }
78     // FIXME: When we switch to use JDK 6 to build SA,
79     // we can change the following to just return:
80     // return new String(bytes, Charset.defaultCharset());
81     return new String(bytes, charset);
82   }
83 }
84