1 files changed, 138 insertions, 0 deletions

diff --git a/src/compiler/scala/tools/nsc/ScriptMain.scala b/src/compiler/scala/tools/nsc/ScriptMain.scala
new file mode 100644
index 0000000000..66e46f6226
--- /dev/null
+++ b/src/compiler/scala/tools/nsc/ScriptMain.scala
@@ -0,0 +1,138 @@
+package scala.tools.nsc
+import java.io.{BufferedReader,FileReader}
+
+/** A main routine to support putting Scala code into scripts.  An example
+ *  script would look like this:
+ *
+ *    #!/bin/sh
+ *    scalascript $0 "$@"
+ *    !#
+ *    Console.println("Hello, world!")
+ *
+ *
+ * TODO: It would be better if error output went to stderr instead
+ * of stdout....
+ */
+object ScriptMain {
+  /** Read the contents of the specified file, skipping the header
+    * part if there is one.  The header part starts with "#!"
+    * and ends with a line that begins with "!#".
+    */
+  def readFileSkippingHeader(filename: String): String = {
+    val file =
+      new BufferedReader(
+          new FileReader(filename))
+    val contents = new StringBuffer
+
+    // skip the header, if there is one
+    val firstLine = file.readLine
+    if(firstLine == null)
+      return ""
+    else if(firstLine.startsWith("#!")) {
+      // skip until !# is seen
+      def lp:Unit = {
+        val line = file.readLine
+        if(line == null)
+          ()
+        else if(!line.startsWith("!#"))
+          lp
+      }
+      lp
+    }
+    else
+      contents.append(firstLine)
+
+    // now read the rest of the file
+    def lp: Unit = {
+      val line = file.readLine
+      if(line == null)
+        return ()
+      contents.append(line)
+      contents.append("\n")
+      lp
+    }
+    lp
+
+    contents.toString
+  }
+
+  /** Print a usage message and then exit. */
+  def usageExit: Nothing = {
+    Console.println(
+        "scalascript [ compiler arguments... - ] scriptfile " +
+        "[ script arguments... ]")
+    Console.println
+    Console.println(
+        "Note that if you do specify compiler arguments, you \n" +
+        "must put an explicit hyphen (\"-\") at the end of them.")
+    System.exit(1).asInstanceOf[Nothing]
+  }
+
+  /** Parse an argument list into three portions:
+    *
+    *   Arguments to the compiler
+    *   The filename of the script to run
+    *   Arguments to pass to the script
+    */
+  def parseArgs(args: List[String])
+      :Tuple3[List[String], String, List[String]] =
+  {
+    if(args.length == 0)
+      usageExit
+
+    if(args(0).startsWith("-")) {
+      // the line includes compiler arguments
+      val hyphenIndex = args.indexOf("-")
+      if(hyphenIndex < 0)
+        usageExit
+      if(hyphenIndex == (args.length - 1))
+        usageExit
+
+      Tuple3(
+        args.subseq(0, hyphenIndex).toList,
+        args(hyphenIndex+1),
+        args.subseq(hyphenIndex+2, args.length - hyphenIndex - 2).toList)
+    } else {
+      Tuple3(
+        Nil,
+        args(0),
+        args.subseq(1, args.length-1).toList)
+    }
+  }
+
+  def main(args: Array[String]): Unit = {
+    val parsedArgs = parseArgs(args.toList)
+    val compilerArgs = parsedArgs._1
+    val scriptFile = parsedArgs._2
+    val scriptArgs = parsedArgs._3.toArray
+
+    val command =
+      new CompilerCommand(
+        compilerArgs,
+        Console.println,
+        false)
+
+    if (!command.ok || command.settings.help.value) {
+      // either the command line is wrong, or the user
+      // explicitly requested a help listing
+      if(!command.ok)
+        Console.println
+      usageExit
+    }
+
+    val scriptContents = readFileSkippingHeader(scriptFile)
+    val toRun =
+      "package scala.scripting\n" +
+      "object Main {\n" +
+      "  def main(argv: Array[String]): Unit = {\n" +
+      scriptContents +
+      "\n} }\n"
+
+    val interpreter = new Interpreter(command.settings)
+    interpreter.beQuiet
+    if(!interpreter.compileString(toRun))
+      return () // compilation error
+    interpreter.bind("argv", "Array[String]", scriptArgs)
+    interpreter.interpret("scala.scripting.Main.main(argv)")
+  }
+}