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Standard library for the Scala Programming Language
/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2006-2013, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala.util
import java.io.{ IOException, PrintWriter }
import java.util.jar.Attributes.{ Name => AttributeName }
/** Loads `library.properties` from the jar. */
object Properties extends PropertiesTrait {
protected def propCategory = "library"
protected def pickJarBasedOn = classOf[Option[_]]
/** Scala manifest attributes.
*/
val ScalaCompilerVersion = new AttributeName("Scala-Compiler-Version")
}
private[scala] trait PropertiesTrait {
protected def propCategory: String // specializes the remainder of the values
protected def pickJarBasedOn: Class[_] // props file comes from jar containing this
/** The name of the properties file */
protected val propFilename = "/" + propCategory + ".properties"
/** The loaded properties */
protected lazy val scalaProps: java.util.Properties = {
val props = new java.util.Properties
val stream = pickJarBasedOn getResourceAsStream propFilename
if (stream ne null)
quietlyDispose(props load stream, stream.close)
props
}
private def quietlyDispose(action: => Unit, disposal: => Unit) =
try { action }
finally {
try { disposal }
catch { case _: IOException => }
}
def propIsSet(name: String) = System.getProperty(name) != null
def propIsSetTo(name: String, value: String) = propOrNull(name) == value
def propOrElse(name: String, alt: String) = System.getProperty(name, alt)
def propOrEmpty(name: String) = propOrElse(name, "")
def propOrNull(name: String) = propOrElse(name, null)
def propOrNone(name: String) = Option(propOrNull(name))
def propOrFalse(name: String) = propOrNone(name) exists (x => List("yes", "on", "true") contains x.toLowerCase)
def setProp(name: String, value: String) = System.setProperty(name, value)
def clearProp(name: String) = System.clearProperty(name)
def envOrElse(name: String, alt: String) = Option(System getenv name) getOrElse alt
def envOrNone(name: String) = Option(System getenv name)
// for values based on propFilename
def scalaPropOrElse(name: String, alt: String): String = scalaProps.getProperty(name, alt)
def scalaPropOrEmpty(name: String): String = scalaPropOrElse(name, "")
def scalaPropOrNone(name: String): Option[String] = Option(scalaProps.getProperty(name))
/** The numeric portion of the runtime Scala version, if this is a final
* release. If for instance the versionString says "version 2.9.0.final",
* this would return Some("2.9.0").
*
* @return Some(version) if this is a final release build, None if
* it is an RC, Beta, etc. or was built from source, or if the version
* cannot be read.
*/
val releaseVersion =
for {
v <- scalaPropOrNone("maven.version.number")
if !(v endsWith "-SNAPSHOT")
} yield v
/** The development Scala version, if this is not a final release.
* The precise contents are not guaranteed, but it aims to provide a
* unique repository identifier (currently the svn revision) in the
* fourth dotted segment if the running version was built from source.
*
* @return Some(version) if this is a non-final version, None if this
* is a final release or the version cannot be read.
*/
val developmentVersion =
for {
v <- scalaPropOrNone("maven.version.number")
if v endsWith "-SNAPSHOT"
ov <- scalaPropOrNone("version.number")
} yield ov
/** Either the development or release version if known, otherwise
* the empty string.
*/
def versionNumberString = scalaPropOrEmpty("version.number")
/** The version number of the jar this was loaded from plus "version " prefix,
* or "version (unknown)" if it cannot be determined.
*/
val versionString = "version " + scalaPropOrElse("version.number", "(unknown)")
val copyrightString = scalaPropOrElse("copyright.string", "Copyright 2002-2013, LAMP/EPFL")
/** This is the encoding to use reading in source files, overridden with -encoding
* Note that it uses "prop" i.e. looks in the scala jar, not the system properties.
*/
def sourceEncoding = scalaPropOrElse("file.encoding", "UTF-8")
def sourceReader = scalaPropOrElse("source.reader", "scala.tools.nsc.io.SourceReader")
/** This is the default text encoding, overridden (unreliably) with
* `JAVA_OPTS="-Dfile.encoding=Foo"`
*/
def encodingString = propOrElse("file.encoding", "UTF-8")
/** The default end of line character.
*/
def lineSeparator = propOrElse("line.separator", "\n")
/** Various well-known properties.
*/
def javaClassPath = propOrEmpty("java.class.path")
def javaHome = propOrEmpty("java.home")
def javaVendor = propOrEmpty("java.vendor")
def javaVersion = propOrEmpty("java.version")
def javaVmInfo = propOrEmpty("java.vm.info")
def javaVmName = propOrEmpty("java.vm.name")
def javaVmVendor = propOrEmpty("java.vm.vendor")
def javaVmVersion = propOrEmpty("java.vm.version")
def osName = propOrEmpty("os.name")
def scalaHome = propOrEmpty("scala.home")
def tmpDir = propOrEmpty("java.io.tmpdir")
def userDir = propOrEmpty("user.dir")
def userHome = propOrEmpty("user.home")
def userName = propOrEmpty("user.name")
/** Some derived values.
*/
def isWin = osName startsWith "Windows"
def isMac = javaVendor startsWith "Apple"
// This is looking for javac, tools.jar, etc.
// Tries JDK_HOME first, then the more common but likely jre JAVA_HOME,
// and finally the system property based javaHome.
def jdkHome = envOrElse("JDK_HOME", envOrElse("JAVA_HOME", javaHome))
def versionMsg = "Scala %s %s -- %s".format(propCategory, versionString, copyrightString)
def scalaCmd = if (isWin) "scala.bat" else "scala"
def scalacCmd = if (isWin) "scalac.bat" else "scalac"
/** Can the java version be determined to be at least as high as the argument?
* Hard to properly future proof this but at the rate 1.7 is going we can leave
* the issue for our cyborg grandchildren to solve.
*/
def isJavaAtLeast(version: String) = {
val okVersions = version match {
case "1.5" => List("1.5", "1.6", "1.7")
case "1.6" => List("1.6", "1.7")
case "1.7" => List("1.7")
case _ => Nil
}
okVersions exists (javaVersion startsWith _)
}
// provide a main method so version info can be obtained by running this
def main(args: Array[String]) {
val writer = new PrintWriter(Console.err, true)
writer println versionMsg
}
}