1. Script mode

Script mode 

sbt has an alternative entry points that may be used to:

  • Compile and execute a Scala script containing dependency declarations or other sbt settings

This entry point should be considered experimental. A notable disadvantage of these approaches is the startup time involved.

sbt Script runner 

The script runner can run a standard Scala script, but with the additional ability to configure sbt. sbt settings may be embedded in the script in a comment block that opens with /***.


Copy the following script and make it executable. You may need to adjust the first line depending on your script name and operating system. When run, the example should retrieve Scala, the required dependencies, compile the script, and run it directly. For example, if you name it script.scala, you would do on Unix:

chmod u+x script.scala
#!/usr/bin/env sbt -Dsbt.version=1.6.1 -Dsbt.main.class=sbt.ScriptMain -error

ThisBuild / scalaVersion := "2.13.8"
libraryDependencies += "org.scala-sbt" %% "io" % "1.6.0"


This prints out hello. If you’re used to using IO from sbt, we can use that do basic file operations, like reading a text file.

#!/usr/bin/env sbt -Dsbt.version=1.6.1 -Dsbt.main.class=sbt.ScriptMain -error

ThisBuild / scalaVersion := "2.13.8"
libraryDependencies += "org.scala-sbt" %% "io" % "1.6.0"

import sbt.io.IO
import sbt.io.Path._
import sbt.io.syntax._
import java.io.File
import java.net.URI
import sys.process._

def file(s: String): File = new File(s)
def uri(s: String): URI = new URI(s)

def processFile(f: File): Unit = {
  val lines = IO.readLines(f)
  lines foreach { line =>

args.toList match {
  case Nil => sys.error("usage: ./script.scala <file>...")
  case xs  => xs foreach { x => processFile(file(x)) }

This script will take file names as argument and print them out in all upper case.

$ ./script.scala script.scala