Write a string to a temporary file in Scala.

write_to_temp_file.scala

import java.io.{ File, PrintWriter }

/** Creates a temporary file, writes the input string to the file, and the file handle.
  *
  * NOTE: This funciton uses the createTempFile function from the File class. The prefix and
  * suffix must be at least 3 characters long, otherwise this function throws an
  * IllegalArgumentException.
  */
def writeToTempFile(contents: String, 
                    prefix: Option[String] = None,
                    suffix: Option[String] = None): File = {
  val tempFi = File.createTempFile(prefix.getOrElse("prefix-"),
                                   suffix.getOrElse("-suffix"))
  tempFi.deleteOnExit()
  new PrintWriter(tempFi) {
    // Any statements inside the body of a class in scala are executed on construction.
    // Therefore, the following try-finally block is executed immediately as we're creating
    // a standard PrinterWriter (with its implementation) and then using it.
    // Alternatively, we could have created the PrintWriter, assigned it a name, 
    // then called .write() and .close() on it. Here, we're simply opting for a terser representation.
    try {
      write(contents)
    } finally {
      close()
    }
  }
  tempFi
}