java.lang.Object
- org.apache.commons.lang.SystemUtils

```
public class SystemUtils
extends java.lang.Object
```
Helpers for java.lang.System.

If a system property cannot be read due to security restrictions, the corresponding field in this class will be set to null and a message will be written to System.err.

#ThreadSafe#

Since:

1.0

Version:

$Id: SystemUtils.java 1056988 2011-01-09 17:58:53Z niallp $

Field Summary

Fields
Modifier and Type	Field	Description
`static java.lang.String`	`AWT_TOOLKIT`	The `awt.toolkit` System Property.
`static java.lang.String`	`FILE_ENCODING`	The `file.encoding` System Property.
`static java.lang.String`	`FILE_SEPARATOR`	The `file.separator` System Property.
`static boolean`	`IS_JAVA_1_1`	Is `true` if this is Java version 1.1 (also 1.1.x versions).
`static boolean`	`IS_JAVA_1_2`	Is `true` if this is Java version 1.2 (also 1.2.x versions).
`static boolean`	`IS_JAVA_1_3`	Is `true` if this is Java version 1.3 (also 1.3.x versions).
`static boolean`	`IS_JAVA_1_4`	Is `true` if this is Java version 1.4 (also 1.4.x versions).
`static boolean`	`IS_JAVA_1_5`	Is `true` if this is Java version 1.5 (also 1.5.x versions).
`static boolean`	`IS_JAVA_1_6`	Is `true` if this is Java version 1.6 (also 1.6.x versions).
`static boolean`	`IS_JAVA_1_7`	Is `true` if this is Java version 1.7 (also 1.7.x versions).
`static boolean`	`IS_OS_AIX`	Is `true` if this is AIX.
`static boolean`	`IS_OS_HP_UX`	Is `true` if this is HP-UX.
`static boolean`	`IS_OS_IRIX`	Is `true` if this is Irix.
`static boolean`	`IS_OS_LINUX`	Is `true` if this is Linux.
`static boolean`	`IS_OS_MAC`	Is `true` if this is Mac.
`static boolean`	`IS_OS_MAC_OSX`	Is `true` if this is Mac.
`static boolean`	`IS_OS_OS2`	Is `true` if this is OS/2.
`static boolean`	`IS_OS_SOLARIS`	Is `true` if this is Solaris.
`static boolean`	`IS_OS_SUN_OS`	Is `true` if this is SunOS.
`static boolean`	`IS_OS_UNIX`	Is `true` if this is a UNIX like system, as in any of AIX, HP-UX, Irix, Linux, MacOSX, Solaris or SUN OS.
`static boolean`	`IS_OS_WINDOWS`	Is `true` if this is Windows.
`static boolean`	`IS_OS_WINDOWS_2000`	Is `true` if this is Windows 2000.
`static boolean`	`IS_OS_WINDOWS_7`	Is `true` if this is Windows 7.
`static boolean`	`IS_OS_WINDOWS_95`	Is `true` if this is Windows 95.
`static boolean`	`IS_OS_WINDOWS_98`	Is `true` if this is Windows 98.
`static boolean`	`IS_OS_WINDOWS_ME`	Is `true` if this is Windows ME.
`static boolean`	`IS_OS_WINDOWS_NT`	Is `true` if this is Windows NT.
`static boolean`	`IS_OS_WINDOWS_VISTA`	Is `true` if this is Windows Vista.
`static boolean`	`IS_OS_WINDOWS_XP`	Is `true` if this is Windows XP.
`static java.lang.String`	`JAVA_AWT_FONTS`	The `java.awt.fonts` System Property.
`static java.lang.String`	`JAVA_AWT_GRAPHICSENV`	The `java.awt.graphicsenv` System Property.
`static java.lang.String`	`JAVA_AWT_HEADLESS`	The `java.awt.headless` System Property.
`static java.lang.String`	`JAVA_AWT_PRINTERJOB`	The `java.awt.printerjob` System Property.
`static java.lang.String`	`JAVA_CLASS_PATH`	The `java.class.path` System Property.
`static java.lang.String`	`JAVA_CLASS_VERSION`	The `java.class.version` System Property.
`static java.lang.String`	`JAVA_COMPILER`	The `java.compiler` System Property.
`static java.lang.String`	`JAVA_ENDORSED_DIRS`	The `java.endorsed.dirs` System Property.
`static java.lang.String`	`JAVA_EXT_DIRS`	The `java.ext.dirs` System Property.
`static java.lang.String`	`JAVA_HOME`	The `java.home` System Property.
`private static java.lang.String`	`JAVA_HOME_KEY`	The System property key for the Java home directory.
`static java.lang.String`	`JAVA_IO_TMPDIR`	The `java.io.tmpdir` System Property.
`private static java.lang.String`	`JAVA_IO_TMPDIR_KEY`	The System property key for the Java IO temporary directory.
`static java.lang.String`	`JAVA_LIBRARY_PATH`	The `java.library.path` System Property.
`static java.lang.String`	`JAVA_RUNTIME_NAME`	The `java.runtime.name` System Property.
`static java.lang.String`	`JAVA_RUNTIME_VERSION`	The `java.runtime.version` System Property.
`static java.lang.String`	`JAVA_SPECIFICATION_NAME`	The `java.specification.name` System Property.
`static java.lang.String`	`JAVA_SPECIFICATION_VENDOR`	The `java.specification.vendor` System Property.
`static java.lang.String`	`JAVA_SPECIFICATION_VERSION`	The `java.specification.version` System Property.
`static java.lang.String`	`JAVA_UTIL_PREFS_PREFERENCES_FACTORY`	The `java.util.prefs.PreferencesFactory` System Property.
`static java.lang.String`	`JAVA_VENDOR`	The `java.vendor` System Property.
`static java.lang.String`	`JAVA_VENDOR_URL`	The `java.vendor.url` System Property.
`static java.lang.String`	`JAVA_VERSION`	The `java.version` System Property.
`static float`	`JAVA_VERSION_FLOAT`	Gets the Java version as a `float`.
`static int`	`JAVA_VERSION_INT`	Gets the Java version as an `int`.
`private static int`	`JAVA_VERSION_TRIM_SIZE`
`static java.lang.String`	`JAVA_VERSION_TRIMMED`	Gets the Java version as a `String` trimming leading letters.
`static java.lang.String`	`JAVA_VM_INFO`	The `java.vm.info` System Property.
`static java.lang.String`	`JAVA_VM_NAME`	The `java.vm.name` System Property.
`static java.lang.String`	`JAVA_VM_SPECIFICATION_NAME`	The `java.vm.specification.name` System Property.
`static java.lang.String`	`JAVA_VM_SPECIFICATION_VENDOR`	The `java.vm.specification.vendor` System Property.
`static java.lang.String`	`JAVA_VM_SPECIFICATION_VERSION`	The `java.vm.specification.version` System Property.
`static java.lang.String`	`JAVA_VM_VENDOR`	The `java.vm.vendor` System Property.
`static java.lang.String`	`JAVA_VM_VERSION`	The `java.vm.version` System Property.
`static java.lang.String`	`LINE_SEPARATOR`	The `line.separator` System Property.
`static java.lang.String`	`OS_ARCH`	The `os.arch` System Property.
`static java.lang.String`	`OS_NAME`	The `os.name` System Property.
`private static java.lang.String`	`OS_NAME_WINDOWS_PREFIX`	The prefix String for all Windows OS.
`static java.lang.String`	`OS_VERSION`	The `os.version` System Property.
`static java.lang.String`	`PATH_SEPARATOR`	The `path.separator` System Property.
`static java.lang.String`	`USER_COUNTRY`	The `user.country` or `user.region` System Property.
`static java.lang.String`	`USER_DIR`	The `user.dir` System Property.
`private static java.lang.String`	`USER_DIR_KEY`	The System property key for the user directory.
`static java.lang.String`	`USER_HOME`	The `user.home` System Property.
`private static java.lang.String`	`USER_HOME_KEY`	The System property key for the user home directory.
`static java.lang.String`	`USER_LANGUAGE`	The `user.language` System Property.
`static java.lang.String`	`USER_NAME`	The `user.name` System Property.
`static java.lang.String`	`USER_TIMEZONE`	The `user.timezone` System Property.

Constructor Summary

Constructors
Constructor Description

SystemUtils()
SystemUtils instances should NOT be constructed in standard programming.

Method Summary

All Methods Static Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`static java.io.File`	`getJavaHome()`	Gets the Java home directory as a `File`.
`static java.io.File`	`getJavaIoTmpDir()`	Gets the Java IO temporary directory as a `File`.
`static float`	`getJavaVersion()`	Deprecated. Use `JAVA_VERSION_FLOAT` instead.
`private static float`	`getJavaVersionAsFloat()`	Gets the Java version number as a `float`.
`private static int`	`getJavaVersionAsInt()`	Gets the Java version number as an `int`.
`private static boolean`	`getJavaVersionMatches(java.lang.String versionPrefix)`	Decides if the Java version matches.
`private static java.lang.String`	`getJavaVersionTrimmed()`	Trims the text of the java version to start with numbers.
`private static boolean`	`getOSMatches(java.lang.String osNamePrefix, java.lang.String osVersionPrefix)`	Decides if the operating system matches.
`private static boolean`	`getOSMatchesName(java.lang.String osNamePrefix)`	Decides if the operating system matches.
`private static java.lang.String`	`getSystemProperty(java.lang.String property)`	Gets a System property, defaulting to `null` if the property cannot be read.
`static java.io.File`	`getUserDir()`	Gets the user directory as a `File`.
`static java.io.File`	`getUserHome()`	Gets the user home directory as a `File`.
`static boolean`	`isJavaAwtHeadless()`	Returns whether the `JAVA_AWT_HEADLESS` value is `true`.
`static boolean`	`isJavaVersionAtLeast(float requiredVersion)`	Is the Java version at least the requested version.
`static boolean`	`isJavaVersionAtLeast(int requiredVersion)`	Is the Java version at least the requested version.
`(package private) static boolean`	`isJavaVersionMatch(java.lang.String version, java.lang.String versionPrefix)`	Decides if the Java version matches.
`(package private) static boolean`	`isOSMatch(java.lang.String osName, java.lang.String osVersion, java.lang.String osNamePrefix, java.lang.String osVersionPrefix)`	Decides if the operating system matches.
`(package private) static boolean`	`isOSNameMatch(java.lang.String osName, java.lang.String osNamePrefix)`	Decides if the operating system matches.
`(package private) static float`	`toJavaVersionFloat(java.lang.String version)`	Converts the given Java version string to a `float`.
`(package private) static int`	`toJavaVersionInt(java.lang.String version)`	Converts the given Java version string to an `int`.
`(package private) static int[]`	`toJavaVersionIntArray(java.lang.String version)`	Converts the given Java version string to an `int[]` of maximum size `3`.
`private static int[]`	`toJavaVersionIntArray(java.lang.String version, int limit)`	Converts the given Java version string to an `int[]` of maximum size `limit`.
`private static float`	`toVersionFloat(int[] javaVersions)`	Converts given the Java version array to a `float`.
`private static int`	`toVersionInt(int[] javaVersions)`	Converts given the Java version array to an `int`.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - JAVA_VERSION_TRIM_SIZE
```
private static final int JAVA_VERSION_TRIM_SIZE
```
    See Also:
    
    Constant Field Values
  - OS_NAME_WINDOWS_PREFIX
```
private static final java.lang.String OS_NAME_WINDOWS_PREFIX
```
    The prefix String for all Windows OS.
    
    See Also:
    
    Constant Field Values
  - USER_HOME_KEY
```
private static final java.lang.String USER_HOME_KEY
```
    The System property key for the user home directory.
    
    See Also:
    
    Constant Field Values
  - USER_DIR_KEY
```
private static final java.lang.String USER_DIR_KEY
```
    The System property key for the user directory.
    
    See Also:
    
    Constant Field Values
  - JAVA_IO_TMPDIR_KEY
```
private static final java.lang.String JAVA_IO_TMPDIR_KEY
```
    The System property key for the Java IO temporary directory.
    
    See Also:
    
    Constant Field Values
  - JAVA_HOME_KEY
```
private static final java.lang.String JAVA_HOME_KEY
```
    The System property key for the Java home directory.
    
    See Also:
    
    Constant Field Values
  - AWT_TOOLKIT
```
public static final java.lang.String AWT_TOOLKIT
```
    The awt.toolkit System Property.
    
    Holds a class name, on Windows XP this is sun.awt.windows.WToolkit.
    
    On platforms without a GUI, this value is null.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    2.1
  - FILE_ENCODING
```
public static final java.lang.String FILE_ENCODING
```
    The file.encoding System Property.
    
    File encoding, such as Cp1252.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    2.0, Java 1.2
  - FILE_SEPARATOR
```
public static final java.lang.String FILE_SEPARATOR
```
    The file.separator System Property. File separator ("/" on UNIX).
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.1
  - JAVA_AWT_FONTS
```
public static final java.lang.String JAVA_AWT_FONTS
```
    The java.awt.fonts System Property.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    2.1
  - JAVA_AWT_GRAPHICSENV
```
public static final java.lang.String JAVA_AWT_GRAPHICSENV
```
    The java.awt.graphicsenv System Property.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    2.1
  - JAVA_AWT_HEADLESS
```
public static final java.lang.String JAVA_AWT_HEADLESS
```
    The java.awt.headless System Property. The value of this property is the String "true" or "false".
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    2.1, Java 1.4
    
    See Also:
    
    isJavaAwtHeadless()
  - JAVA_AWT_PRINTERJOB
```
public static final java.lang.String JAVA_AWT_PRINTERJOB
```
    The java.awt.printerjob System Property.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    2.1
  - JAVA_CLASS_PATH
```
public static final java.lang.String JAVA_CLASS_PATH
```
    The java.class.path System Property. Java class path.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.1
  - JAVA_CLASS_VERSION
```
public static final java.lang.String JAVA_CLASS_VERSION
```
    The java.class.version System Property. Java class format version number.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.1
  - JAVA_COMPILER
```
public static final java.lang.String JAVA_COMPILER
```
    The java.compiler System Property. Name of JIT compiler to use. First in JDK version 1.2. Not used in Sun JDKs after 1.2.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.2. Not used in Sun versions after 1.2.
  - JAVA_ENDORSED_DIRS
```
public static final java.lang.String JAVA_ENDORSED_DIRS
```
    The java.endorsed.dirs System Property. Path of endorsed directory or directories.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.4
  - JAVA_EXT_DIRS
```
public static final java.lang.String JAVA_EXT_DIRS
```
    The java.ext.dirs System Property. Path of extension directory or directories.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.3
  - JAVA_HOME
```
public static final java.lang.String JAVA_HOME
```
    The java.home System Property. Java installation directory.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.1
  - JAVA_IO_TMPDIR
```
public static final java.lang.String JAVA_IO_TMPDIR
```
    The java.io.tmpdir System Property. Default temp file path.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.2
  - JAVA_LIBRARY_PATH
```
public static final java.lang.String JAVA_LIBRARY_PATH
```
    The java.library.path System Property. List of paths to search when loading libraries.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.2
  - JAVA_RUNTIME_NAME
```
public static final java.lang.String JAVA_RUNTIME_NAME
```
    The java.runtime.name System Property. Java Runtime Environment name.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    2.0, Java 1.3
  - JAVA_RUNTIME_VERSION
```
public static final java.lang.String JAVA_RUNTIME_VERSION
```
    The java.runtime.version System Property. Java Runtime Environment version.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    2.0, Java 1.3
  - JAVA_SPECIFICATION_NAME
```
public static final java.lang.String JAVA_SPECIFICATION_NAME
```
    The java.specification.name System Property. Java Runtime Environment specification name.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.2
  - JAVA_SPECIFICATION_VENDOR
```
public static final java.lang.String JAVA_SPECIFICATION_VENDOR
```
    The java.specification.vendor System Property. Java Runtime Environment specification vendor.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.2
  - JAVA_SPECIFICATION_VERSION
```
public static final java.lang.String JAVA_SPECIFICATION_VERSION
```
    The java.specification.version System Property. Java Runtime Environment specification version.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.3
  - JAVA_UTIL_PREFS_PREFERENCES_FACTORY
```
public static final java.lang.String JAVA_UTIL_PREFS_PREFERENCES_FACTORY
```
    The java.util.prefs.PreferencesFactory System Property. A class name.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    2.1, Java 1.4
  - JAVA_VENDOR
```
public static final java.lang.String JAVA_VENDOR
```
    The java.vendor System Property. Java vendor-specific string.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.1
  - JAVA_VENDOR_URL
```
public static final java.lang.String JAVA_VENDOR_URL
```
    The java.vendor.url System Property. Java vendor URL.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.1
  - JAVA_VERSION
```
public static final java.lang.String JAVA_VERSION
```
    The java.version System Property. Java version number.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.1
  - JAVA_VM_INFO
```
public static final java.lang.String JAVA_VM_INFO
```
    The java.vm.info System Property. Java Virtual Machine implementation info.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    2.0, Java 1.2
  - JAVA_VM_NAME
```
public static final java.lang.String JAVA_VM_NAME
```
    The java.vm.name System Property. Java Virtual Machine implementation name.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.2
  - JAVA_VM_SPECIFICATION_NAME
```
public static final java.lang.String JAVA_VM_SPECIFICATION_NAME
```
    The java.vm.specification.name System Property. Java Virtual Machine specification name.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.2
  - JAVA_VM_SPECIFICATION_VENDOR
```
public static final java.lang.String JAVA_VM_SPECIFICATION_VENDOR
```
    The java.vm.specification.vendor System Property. Java Virtual Machine specification vendor.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.2
  - JAVA_VM_SPECIFICATION_VERSION
```
public static final java.lang.String JAVA_VM_SPECIFICATION_VERSION
```
    The java.vm.specification.version System Property. Java Virtual Machine specification version.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.2
  - JAVA_VM_VENDOR
```
public static final java.lang.String JAVA_VM_VENDOR
```
    The java.vm.vendor System Property. Java Virtual Machine implementation vendor.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.2
  - JAVA_VM_VERSION
```
public static final java.lang.String JAVA_VM_VERSION
```
    The java.vm.version System Property. Java Virtual Machine implementation version.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.2
  - LINE_SEPARATOR
```
public static final java.lang.String LINE_SEPARATOR
```
    The line.separator System Property. Line separator ("\n" on UNIX).
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.1
  - OS_ARCH
```
public static final java.lang.String OS_ARCH
```
    The os.arch System Property. Operating system architecture.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.1
  - OS_NAME
```
public static final java.lang.String OS_NAME
```
    The os.name System Property. Operating system name.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.1
  - OS_VERSION
```
public static final java.lang.String OS_VERSION
```
    The os.version System Property. Operating system version.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.1
  - PATH_SEPARATOR
```
public static final java.lang.String PATH_SEPARATOR
```
    The path.separator System Property. Path separator (":" on UNIX).
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.1
  - USER_COUNTRY
```
public static final java.lang.String USER_COUNTRY
```
    The user.country or user.region System Property. User's country code, such as GB. First in Java version 1.2 as user.region. Renamed to user.country in 1.4
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    2.0, Java 1.2
  - USER_DIR
```
public static final java.lang.String USER_DIR
```
    The user.dir System Property. User's current working directory.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.1
  - USER_HOME
```
public static final java.lang.String USER_HOME
```
    The user.home System Property. User's home directory.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.1
  - USER_LANGUAGE
```
public static final java.lang.String USER_LANGUAGE
```
    The user.language System Property. User's language code, such as "en".
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    2.0, Java 1.2
  - USER_NAME
```
public static final java.lang.String USER_NAME
```
    The user.name System Property. User's account name.
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    Java 1.1
  - USER_TIMEZONE
```
public static final java.lang.String USER_TIMEZONE
```
    The user.timezone System Property. For example: "America/Los_Angeles".
    
    Defaults to null if the runtime does not have security access to read this property or the property does not exist.
    
    This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.
    
    Since:
    
    2.1
  - JAVA_VERSION_TRIMMED
```
public static final java.lang.String JAVA_VERSION_TRIMMED
```
    Gets the Java version as a String trimming leading letters.
    
    The field will return null if JAVA_VERSION is null.
    
    Since:
    
    2.1
  - JAVA_VERSION_FLOAT
```
public static final float JAVA_VERSION_FLOAT
```
    Gets the Java version as a float.
    
    Example return values:
    
    1.2f for Java 1.2
    1.31f for Java 1.3.1
    
    The field will return zero if JAVA_VERSION is null.
    Since:
    
    2.0
  - JAVA_VERSION_INT
```
public static final int JAVA_VERSION_INT
```
    Gets the Java version as an int.
    
    Example return values:
    
    120 for Java 1.2
    131 for Java 1.3.1
    
    The field will return zero if JAVA_VERSION is null.
    Since:
    
    2.0
  - IS_JAVA_1_1
```
public static final boolean IS_JAVA_1_1
```
    Is true if this is Java version 1.1 (also 1.1.x versions).
    
    The field will return false if JAVA_VERSION is null.
  - IS_JAVA_1_2
```
public static final boolean IS_JAVA_1_2
```
    Is true if this is Java version 1.2 (also 1.2.x versions).
    
    The field will return false if JAVA_VERSION is null.
  - IS_JAVA_1_3
```
public static final boolean IS_JAVA_1_3
```
    Is true if this is Java version 1.3 (also 1.3.x versions).
    
    The field will return false if JAVA_VERSION is null.
  - IS_JAVA_1_4
```
public static final boolean IS_JAVA_1_4
```
    Is true if this is Java version 1.4 (also 1.4.x versions).
    
    The field will return false if JAVA_VERSION is null.
  - IS_JAVA_1_5
```
public static final boolean IS_JAVA_1_5
```
    Is true if this is Java version 1.5 (also 1.5.x versions).
    
    The field will return false if JAVA_VERSION is null.
  - IS_JAVA_1_6
```
public static final boolean IS_JAVA_1_6
```
    Is true if this is Java version 1.6 (also 1.6.x versions).
    
    The field will return false if JAVA_VERSION is null.
  - IS_JAVA_1_7
```
public static final boolean IS_JAVA_1_7
```
    Is true if this is Java version 1.7 (also 1.7.x versions).
    
    The field will return false if JAVA_VERSION is null.
    
    Since:
    
    2.5
  - IS_OS_AIX
```
public static final boolean IS_OS_AIX
```
    Is true if this is AIX.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.0
  - IS_OS_HP_UX
```
public static final boolean IS_OS_HP_UX
```
    Is true if this is HP-UX.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.0
  - IS_OS_IRIX
```
public static final boolean IS_OS_IRIX
```
    Is true if this is Irix.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.0
  - IS_OS_LINUX
```
public static final boolean IS_OS_LINUX
```
    Is true if this is Linux.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.0
  - IS_OS_MAC
```
public static final boolean IS_OS_MAC
```
    Is true if this is Mac.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.0
  - IS_OS_MAC_OSX
```
public static final boolean IS_OS_MAC_OSX
```
    Is true if this is Mac.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.0
  - IS_OS_OS2
```
public static final boolean IS_OS_OS2
```
    Is true if this is OS/2.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.0
  - IS_OS_SOLARIS
```
public static final boolean IS_OS_SOLARIS
```
    Is true if this is Solaris.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.0
  - IS_OS_SUN_OS
```
public static final boolean IS_OS_SUN_OS
```
    Is true if this is SunOS.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.0
  - IS_OS_UNIX
```
public static final boolean IS_OS_UNIX
```
    Is true if this is a UNIX like system, as in any of AIX, HP-UX, Irix, Linux, MacOSX, Solaris or SUN OS.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.1
  - IS_OS_WINDOWS
```
public static final boolean IS_OS_WINDOWS
```
    Is true if this is Windows.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.0
  - IS_OS_WINDOWS_2000
```
public static final boolean IS_OS_WINDOWS_2000
```
    Is true if this is Windows 2000.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.0
  - IS_OS_WINDOWS_95
```
public static final boolean IS_OS_WINDOWS_95
```
    Is true if this is Windows 95.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.0
  - IS_OS_WINDOWS_98
```
public static final boolean IS_OS_WINDOWS_98
```
    Is true if this is Windows 98.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.0
  - IS_OS_WINDOWS_ME
```
public static final boolean IS_OS_WINDOWS_ME
```
    Is true if this is Windows ME.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.0
  - IS_OS_WINDOWS_NT
```
public static final boolean IS_OS_WINDOWS_NT
```
    Is true if this is Windows NT.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.0
  - IS_OS_WINDOWS_XP
```
public static final boolean IS_OS_WINDOWS_XP
```
    Is true if this is Windows XP.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.0
  - IS_OS_WINDOWS_VISTA
```
public static final boolean IS_OS_WINDOWS_VISTA
```
    Is true if this is Windows Vista.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.4
  - IS_OS_WINDOWS_7
```
public static final boolean IS_OS_WINDOWS_7
```
    Is true if this is Windows 7.
    
    The field will return false if OS_NAME is null.
    
    Since:
    
    2.5
- Constructor Detail
  - SystemUtils
```
public SystemUtils()
```
    SystemUtils instances should NOT be constructed in standard programming. Instead, the class should be used as SystemUtils.FILE_SEPARATOR.
    
    This constructor is public to permit tools that require a JavaBean instance to operate.
- Method Detail
  - getJavaHome
```
public static java.io.File getJavaHome()
```
    Gets the Java home directory as a File.
    
    Returns:
    
    a directory
    
    Throws:
    
    java.lang.SecurityException - if a security manager exists and its checkPropertyAccess method doesn't allow access to the specified system property.
    
    Since:
    
    2.1
    
    See Also:
    
    System.getProperty(String)
  - getJavaIoTmpDir
```
public static java.io.File getJavaIoTmpDir()
```
    Gets the Java IO temporary directory as a File.
    
    Returns:
    
    a directory
    
    Throws:
    
    java.lang.SecurityException - if a security manager exists and its checkPropertyAccess method doesn't allow access to the specified system property.
    
    Since:
    
    2.1
    
    See Also:
    
    System.getProperty(String)
  - getJavaVersion
```
public static float getJavaVersion()
```
    Deprecated.
    Use JAVA_VERSION_FLOAT instead. Method will be removed in Commons Lang 3.0.
    Gets the Java version number as a float.
    
    Example return values:
    
    1.2f for JDK 1.2
    1.31f for JDK 1.3.1
    Returns:
    
    the version, for example 1.31f for JDK 1.3.1
  - getJavaVersionAsFloat
```
private static float getJavaVersionAsFloat()
```
    Gets the Java version number as a float.
    
    Example return values:
    
    1.2f for Java 1.2
    
    1.31f for Java 1.3.1
    
    1.6f for Java 1.6.0_20
    
    Patch releases are not reported.
    Returns:
    
    the version, for example 1.31f for Java 1.3.1
  - getJavaVersionAsInt
```
private static int getJavaVersionAsInt()
```
    Gets the Java version number as an int.
    
    Example return values:
    
    120 for Java 1.2
    
    131 for Java 1.3.1
    
    160 for Java 1.6.0_20
    
    Patch releases are not reported.
    Returns:
    
    the version, for example 131 for Java 1.3.1
  - getJavaVersionMatches
```
private static boolean getJavaVersionMatches(java.lang.String versionPrefix)
```
    Decides if the Java version matches.
    
    Parameters:
    
    versionPrefix - the prefix for the java version
    
    Returns:
    
    true if matches, or false if not or can't determine
  - getJavaVersionTrimmed
```
private static java.lang.String getJavaVersionTrimmed()
```
    Trims the text of the java version to start with numbers.
    
    Returns:
    
    the trimmed java version
  - getOSMatches
```
private static boolean getOSMatches(java.lang.String osNamePrefix,
                                    java.lang.String osVersionPrefix)
```
    Decides if the operating system matches.
    
    Parameters:
    
    osNamePrefix - the prefix for the os name
    
    osVersionPrefix - the prefix for the version
    
    Returns:
    
    true if matches, or false if not or can't determine
  - getOSMatchesName
```
private static boolean getOSMatchesName(java.lang.String osNamePrefix)
```
    Decides if the operating system matches.
    
    Parameters:
    
    osNamePrefix - the prefix for the os name
    
    Returns:
    
    true if matches, or false if not or can't determine
  - getSystemProperty
```
private static java.lang.String getSystemProperty(java.lang.String property)
```
    Gets a System property, defaulting to null if the property cannot be read.
    
    If a SecurityException is caught, the return value is null and a message is written to System.err.
    
    Parameters:
    
    property - the system property name
    
    Returns:
    
    the system property value or null if a security problem occurs
  - getUserDir
```
public static java.io.File getUserDir()
```
    Gets the user directory as a File.
    
    Returns:
    
    a directory
    
    Throws:
    
    java.lang.SecurityException - if a security manager exists and its checkPropertyAccess method doesn't allow access to the specified system property.
    
    Since:
    
    2.1
    
    See Also:
    
    System.getProperty(String)
  - getUserHome
```
public static java.io.File getUserHome()
```
    Gets the user home directory as a File.
    
    Returns:
    
    a directory
    
    Throws:
    
    java.lang.SecurityException - if a security manager exists and its checkPropertyAccess method doesn't allow access to the specified system property.
    
    Since:
    
    2.1
    
    See Also:
    
    System.getProperty(String)
  - isJavaAwtHeadless
```
public static boolean isJavaAwtHeadless()
```
    Returns whether the JAVA_AWT_HEADLESS value is true.
    
    Returns:
    
    true if JAVA_AWT_HEADLESS is "true", false otherwise.
    
    Since:
    
    2.1, Java 1.4
    
    See Also:
    
    JAVA_AWT_HEADLESS
  - isJavaVersionAtLeast
```
public static boolean isJavaVersionAtLeast(float requiredVersion)
```
    Is the Java version at least the requested version.
    
    Example input:
    
    1.2f to test for Java 1.2
    
    1.31f to test for Java 1.3.1
    Parameters:
    
    requiredVersion - the required version, for example 1.31f
    
    Returns:
    
    true if the actual version is equal or greater than the required version
  - isJavaVersionAtLeast
```
public static boolean isJavaVersionAtLeast(int requiredVersion)
```
    Is the Java version at least the requested version.
    
    Example input:
    
    120 to test for Java 1.2 or greater
    
    131 to test for Java 1.3.1 or greater
    Parameters:
    
    requiredVersion - the required version, for example 131
    
    Returns:
    
    true if the actual version is equal or greater than the required version
    
    Since:
    
    2.0
  - isJavaVersionMatch
```
static boolean isJavaVersionMatch(java.lang.String version,
                                  java.lang.String versionPrefix)
```
    Decides if the Java version matches.
    
    This method is package private instead of private to support unit test invocation.
    
    Parameters:
    
    version - the actual Java version
    
    versionPrefix - the prefix for the expected Java version
    
    Returns:
    
    true if matches, or false if not or can't determine
  - isOSMatch
```
static boolean isOSMatch(java.lang.String osName,
                         java.lang.String osVersion,
                         java.lang.String osNamePrefix,
                         java.lang.String osVersionPrefix)
```
    Decides if the operating system matches.
    This method is package private instead of private to support unit test invocation.
    
    Parameters:
    
    osName - the actual OS name
    
    osVersion - the actual OS version
    
    osNamePrefix - the prefix for the expected OS name
    
    osVersionPrefix - the prefix for the expected OS version
    
    Returns:
    
    true if matches, or false if not or can't determine
  - isOSNameMatch
```
static boolean isOSNameMatch(java.lang.String osName,
                             java.lang.String osNamePrefix)
```
    Decides if the operating system matches.
    This method is package private instead of private to support unit test invocation.
    
    Parameters:
    
    osName - the actual OS name
    
    osNamePrefix - the prefix for the expected OS name
    
    Returns:
    
    true if matches, or false if not or can't determine
  - toJavaVersionFloat
```
static float toJavaVersionFloat(java.lang.String version)
```
    Converts the given Java version string to a float.
    
    Example return values:
    
    1.2f for Java 1.2
    
    1.31f for Java 1.3.1
    
    1.6f for Java 1.6.0_20
    
    Patch releases are not reported.
    
    This method is package private instead of private to support unit test invocation.
    Parameters:
    
    version - The string version
    
    Returns:
    
    the version, for example 1.31f for Java 1.3.1
  - toJavaVersionInt
```
static int toJavaVersionInt(java.lang.String version)
```
    Converts the given Java version string to an int.
    
    Example return values:
    
    120 for Java 1.2
    
    131 for Java 1.3.1
    
    160 for Java 1.6.0_20
    
    Patch releases are not reported.
    
    This method is package private instead of private to support unit test invocation.
    Parameters:
    
    version - The string version
    
    Returns:
    
    the version, for example 131 for Java 1.3.1
  - toJavaVersionIntArray
```
static int[] toJavaVersionIntArray(java.lang.String version)
```
    Converts the given Java version string to an int[] of maximum size 3.
    
    Example return values:
    
    [1, 2, 0] for Java 1.2
    
    [1, 3, 1] for Java 1.3.1
    
    [1, 5, 0] for Java 1.5.0_21
    
    This method is package private instead of private to support unit test invocation.
    Parameters:
    
    version - The string version
    
    Returns:
    
    the version, for example [1, 5, 0] for Java 1.5.0_21
  - toJavaVersionIntArray
```
private static int[] toJavaVersionIntArray(java.lang.String version,
                                           int limit)
```
    Converts the given Java version string to an int[] of maximum size limit.
    
    Example return values:
    
    [1, 2, 0] for Java 1.2
    
    [1, 3, 1] for Java 1.3.1
    
    [1, 5, 0, 21] for Java 1.5.0_21
    Parameters:
    
    version - The string version
    
    limit - version limit
    
    Returns:
    
    the version, for example [1, 5, 0, 21] for Java 1.5.0_21
  - toVersionFloat
```
private static float toVersionFloat(int[] javaVersions)
```
    Converts given the Java version array to a float.
    
    Example return values:
    
    1.2f for Java 1.2
    
    1.31f for Java 1.3.1
    
    1.6f for Java 1.6.0_20
    
    Patch releases are not reported.
    Parameters:
    
    javaVersions - The version numbers
    
    Returns:
    
    the version, for example 1.31f for Java 1.3.1
  - toVersionInt
```
private static int toVersionInt(int[] javaVersions)
```
    Converts given the Java version array to an int.
    
    Example return values:
    
    120 for Java 1.2
    
    131 for Java 1.3.1
    
    160 for Java 1.6.0_20
    
    Patch releases are not reported.
    Parameters:
    
    javaVersions - The version numbers
    
    Returns:
    
    the version, for example 1.31f for Java 1.3.1

Class SystemUtils

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

JAVA_VERSION_TRIM_SIZE

OS_NAME_WINDOWS_PREFIX

USER_HOME_KEY

USER_DIR_KEY

JAVA_IO_TMPDIR_KEY

JAVA_HOME_KEY

AWT_TOOLKIT

FILE_ENCODING

FILE_SEPARATOR

JAVA_AWT_FONTS

JAVA_AWT_GRAPHICSENV

JAVA_AWT_HEADLESS

JAVA_AWT_PRINTERJOB

JAVA_CLASS_PATH

JAVA_CLASS_VERSION

JAVA_COMPILER

JAVA_ENDORSED_DIRS

JAVA_EXT_DIRS

JAVA_HOME

JAVA_IO_TMPDIR

JAVA_LIBRARY_PATH

JAVA_RUNTIME_NAME

JAVA_RUNTIME_VERSION

JAVA_SPECIFICATION_NAME

JAVA_SPECIFICATION_VENDOR

JAVA_SPECIFICATION_VERSION

JAVA_UTIL_PREFS_PREFERENCES_FACTORY

JAVA_VENDOR

JAVA_VENDOR_URL

JAVA_VERSION

JAVA_VM_INFO

JAVA_VM_NAME

JAVA_VM_SPECIFICATION_NAME

JAVA_VM_SPECIFICATION_VENDOR

JAVA_VM_SPECIFICATION_VERSION

JAVA_VM_VENDOR

JAVA_VM_VERSION

LINE_SEPARATOR

OS_ARCH

OS_NAME

OS_VERSION

PATH_SEPARATOR

USER_COUNTRY

USER_DIR

USER_HOME

USER_LANGUAGE

USER_NAME

USER_TIMEZONE

JAVA_VERSION_TRIMMED

JAVA_VERSION_FLOAT

JAVA_VERSION_INT

IS_JAVA_1_1

IS_JAVA_1_2

IS_JAVA_1_3

IS_JAVA_1_4

IS_JAVA_1_5

IS_JAVA_1_6

IS_JAVA_1_7

IS_OS_AIX

IS_OS_HP_UX

IS_OS_IRIX

IS_OS_LINUX

IS_OS_MAC

IS_OS_MAC_OSX

IS_OS_OS2

IS_OS_SOLARIS

IS_OS_SUN_OS

IS_OS_UNIX

IS_OS_WINDOWS

IS_OS_WINDOWS_2000

IS_OS_WINDOWS_95

IS_OS_WINDOWS_98

IS_OS_WINDOWS_ME

IS_OS_WINDOWS_NT