/*
* Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/* We use APIs that access a so-called Windows "Environment Block",
* which looks like an array of jchars like this:
*
* FOO=BAR\u0000 ... GORP=QUUX\u0000\u0000
*
* This data structure has a number of peculiarities we must contend with:
* (see: http://windowssdk.msdn.microsoft.com/en-us/library/ms682009.aspx)
* - The NUL jchar separators, and a double NUL jchar terminator.
* It appears that the Windows implementation requires double NUL
* termination even if the environment is empty. We should always
* generate environments with double NUL termination, while accepting
* empty environments consisting of a single NUL.
* - on Windows9x, this is actually an array of 8-bit chars, not jchars,
* encoded in the system default encoding.
* - The block must be sorted by Unicode value, case-insensitively,
* as if folded to upper case.
* - There are magic environment variables maintained by Windows
* that start with a `=' (!) character. These are used for
* Windows drive current directory (e.g. "=C:=C:\WINNT") or the
* exit code of the last command (e.g. "=ExitCode=0000001").
*
* Since Java and non-9x Windows speak the same character set, and
* even the same encoding, we don't have to deal with unreliable
* conversion to byte streams. Just add a few NUL terminators.
*
* System.getenv(String) is case-insensitive, while System.getenv()
* returns a map that is case-sensitive, which is consistent with
* native Windows APIs.
*
* The non-private methods in this class are not for general use even
* within this package. Instead, they are the system-dependent parts
* of the system-independent method of the same name. Don't even
* think of using this class unless your method's name appears below.
*
* @author Martin Buchholz
* @since 1.5
*/
package java.lang;
import java.io.*;
import java.util.*;
final class ProcessEnvironment extends HashMap<String,String>
{
private static String validateName(String name) {
// An initial `=' indicates a magic Windows variable name -- OK
if (name.indexOf('=', 1) != -1 ||
name.indexOf('\u0000') != -1)
throw new IllegalArgumentException
("Invalid environment variable name: \"" + name + "\"");
return name;
}
private static String validateValue(String value) {
if (value.indexOf('\u0000') != -1)
throw new IllegalArgumentException
("Invalid environment variable value: \"" + value + "\"");
return value;
}
private static String nonNullString(Object o) {
if (o == null)
throw new NullPointerException();
return (String) o;
}
public String put(String key, String value) {
return super.put(validateName(key), validateValue(value));
}
public String get(Object key) {
return super.get(nonNullString(key));
}
public boolean containsKey(Object key) {
return super.containsKey(nonNullString(key));
}
public boolean containsValue(Object value) {
return super.containsValue(nonNullString(value));
}
public String remove(Object key) {
return super.remove(nonNullString(key));
}
private static class CheckedEntry
implements Map.Entry<String,String>
{
private final Map.Entry<String,String> e;
public CheckedEntry(Map.Entry<String,String> e) {this.e = e;}
public String getKey() { return e.getKey();}
public String getValue() { return e.getValue();}
public String setValue(String value) {
return e.setValue(validateValue(value));
}
public String toString() { return getKey() + "=" + getValue();}
public boolean equals(Object o) {return e.equals(o);}
public int hashCode() {return e.hashCode();}
}
private static class CheckedEntrySet
extends AbstractSet<Map.Entry<String,String>>
{
private final Set<Map.Entry<String,String>> s;
public CheckedEntrySet(Set<Map.Entry<String,String>> s) {this.s = s;}
public int size() {return s.size();}
public boolean isEmpty() {return s.isEmpty();}
public void clear() { s.clear();}
public Iterator<Map.Entry<String,String>> iterator() {
return new Iterator<Map.Entry<String,String>>() {
Iterator<Map.Entry<String,String>> i = s.iterator();
public boolean hasNext() { return i.hasNext();}
public Map.Entry<String,String> next() {
return new CheckedEntry(i.next());
}
public void remove() { i.remove();}
};
}
private static Map.Entry<String,String> checkedEntry(Object o) {
Map.Entry<String,String> e = (Map.Entry<String,String>) o;
nonNullString(e.getKey());
nonNullString(e.getValue());
return e;
}
public boolean contains(Object o) {return s.contains(checkedEntry(o));}
public boolean remove(Object o) {return s.remove(checkedEntry(o));}
}
private static class CheckedValues extends AbstractCollection<String> {
private final Collection<String> c;
public CheckedValues(Collection<String> c) {this.c = c;}
public int size() {return c.size();}
public boolean isEmpty() {return c.isEmpty();}
public void clear() { c.clear();}
public Iterator<String> iterator() {return c.iterator();}
public boolean contains(Object o) {return c.contains(nonNullString(o));}
public boolean remove(Object o) {return c.remove(nonNullString(o));}
}
private static class CheckedKeySet extends AbstractSet<String> {
private final Set<String> s;
public CheckedKeySet(Set<String> s) {this.s = s;}
public int size() {return s.size();}
public boolean isEmpty() {return s.isEmpty();}
public void clear() { s.clear();}
public Iterator<String> iterator() {return s.iterator();}
public boolean contains(Object o) {return s.contains(nonNullString(o));}
public boolean remove(Object o) {return s.remove(nonNullString(o));}
}
public Set<String> keySet() {
return new CheckedKeySet(super.keySet());
}
public Collection<String> values() {
return new CheckedValues(super.values());
}
public Set<Map.Entry<String,String>> entrySet() {
return new CheckedEntrySet(super.entrySet());
}
private static final class NameComparator
implements Comparator<String> {
public int compare(String s1, String s2) {
// We can't use String.compareToIgnoreCase since it
// canonicalizes to lower case, while Windows
// canonicalizes to upper case! For example, "_" should
// sort *after* "Z", not before.
int n1 = s1.length();
int n2 = s2.length();
int min = Math.min(n1, n2);
for (int i = 0; i < min; i++) {
char c1 = s1.charAt(i);
char c2 = s2.charAt(i);
if (c1 != c2) {
c1 = Character.toUpperCase(c1);
c2 = Character.toUpperCase(c2);
if (c1 != c2)
// No overflow because of numeric promotion
return c1 - c2;
}
}
return n1 - n2;
}
}
private static final class EntryComparator
implements Comparator<Map.Entry<String,String>> {
public int compare(Map.Entry<String,String> e1,
Map.Entry<String,String> e2) {
return nameComparator.compare(e1.getKey(), e2.getKey());
}
}
// Allow `=' as first char in name, e.g. =C:=C:\DIR
static final int MIN_NAME_LENGTH = 1;
private static final NameComparator nameComparator;
private static final EntryComparator entryComparator;
private static final ProcessEnvironment theEnvironment;
private static final Map<String,String> theUnmodifiableEnvironment;
private static final Map<String,String> theCaseInsensitiveEnvironment;
static {
nameComparator = new NameComparator();
entryComparator = new EntryComparator();
theEnvironment = new ProcessEnvironment();
theUnmodifiableEnvironment
= Collections.unmodifiableMap(theEnvironment);
String envblock = environmentBlock();
int beg, end, eql;
for (beg = 0;
((end = envblock.indexOf('\u0000', beg )) != -1 &&
// An initial `=' indicates a magic Windows variable name -- OK
(eql = envblock.indexOf('=' , beg+1)) != -1);
beg = end + 1) {
// Ignore corrupted environment strings.
if (eql < end)
theEnvironment.put(envblock.substring(beg, eql),
envblock.substring(eql+1,end));
}
theCaseInsensitiveEnvironment = new TreeMap<>(nameComparator);
theCaseInsensitiveEnvironment.putAll(theEnvironment);
}
private ProcessEnvironment() {
super();
}
private ProcessEnvironment(int capacity) {
super(capacity);
}
// Only for use by System.getenv(String)
static String getenv(String name) {
// The original implementation used a native call to _wgetenv,
// but it turns out that _wgetenv is only consistent with
// GetEnvironmentStringsW (for non-ASCII) if `wmain' is used
// instead of `main', even in a process created using
// CREATE_UNICODE_ENVIRONMENT. Instead we perform the
// case-insensitive comparison ourselves. At least this
// guarantees that System.getenv().get(String) will be
// consistent with System.getenv(String).
return theCaseInsensitiveEnvironment.get(name);
}
// Only for use by System.getenv()
static Map<String,String> getenv() {
return theUnmodifiableEnvironment;
}
// Only for use by ProcessBuilder.environment()
static Map<String,String> environment() {
return (Map<String,String>) theEnvironment.clone();
}
// Only for use by ProcessBuilder.environment(String[] envp)
static Map<String,String> emptyEnvironment(int capacity) {
return new ProcessEnvironment(capacity);
}
private static native String environmentBlock();
// Only for use by ProcessImpl.start()
String toEnvironmentBlock() {
// Sort Unicode-case-insensitively by name
List<Map.Entry<String,String>> list = new ArrayList<>(entrySet());
Collections.sort(list, entryComparator);
StringBuilder sb = new StringBuilder(size()*30);
int cmp = -1;
// Some versions of MSVCRT.DLL require SystemRoot to be set.
// So, we make sure that it is always set, even if not provided
// by the caller.
final String SYSTEMROOT = "SystemRoot";
for (Map.Entry<String,String> e : list) {
String key = e.getKey();
String value = e.getValue();
if (cmp < 0 && (cmp = nameComparator.compare(key, SYSTEMROOT)) > 0) {
// Not set, so add it here
addToEnvIfSet(sb, SYSTEMROOT);
}
addToEnv(sb, key, value);
}
if (cmp < 0) {
// Got to end of list and still not found
addToEnvIfSet(sb, SYSTEMROOT);
}
if (sb.length() == 0) {
// Environment was empty and SystemRoot not set in parent
sb.append('\u0000');
}
// Block is double NUL terminated
sb.append('\u0000');
return sb.toString();
}
// add the environment variable to the child, if it exists in parent
private static void addToEnvIfSet(StringBuilder sb, String name) {
String s = getenv(name);
if (s != null)
addToEnv(sb, name, s);
}
private static void addToEnv(StringBuilder sb, String name, String val) {
sb.append(name).append('=').append(val).append('\u0000');
}
static String toEnvironmentBlock(Map<String,String> map) {
return map == null ? null :
((ProcessEnvironment)map).toEnvironmentBlock();
}
}