Display all envs vars
printenv
Set $JAVA_HOME and $SCALA_HOME (Mac OS X)
export JAVA_HOME=$(/usr/libexec/java_home)
export SCALA_HOME=/usr/local/share/scala
export PATH=${PATH}:$JAVA_HOME/bin:$SCALA_HOME/bin
Display Java, Scala versions
javac -version
scala -version
Scala command line
scala
:q