The general consensus from what I've read is that to execute a system command in Scala, you should use the Java runtime features. I don't like this, Scala should be more concise than Java. SBT has classes to execute system commands, however, these are generally only available in your build code. To use this code in your program, download these two files: Process.scala and ProcessImpl.scala (available at the Github repo xsbt's util process). Put these files in your src, and then:
Calling !! will block until the command is finished, output errors to stderr, and return the output form the command. If the command returns a non-zero code, and exception is thrown. Calling ! will block, output to stderr and stdout, and return the return code of the command. No exeception is thrown when using !. Look at the code for the ProcessBuilder trait to see other functions that you can call, there are many.