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/* NSC -- new Scala compiler
* Copyright 2005-2006 LAMP/EPFL
* @author Martin Odersky
*/
// $Id: $
package scala.tools.nsc
import java.io.{BufferedReader,FileReader}
/** A main routine to support putting Scala code into scripts.
*
* An shell script example on Unix would look like this:
*
* #!/bin/sh
* exec scalascript "$0" "$@"
* !#
* Console.println("Hello, world!")
* argv.toList foreach Console.println
*
* A batch file example on Windows XP would look like this:
*
* ::#!
* @echo off
* call scalascript %0 %*
* goto :eof
* ::!#
* Console.println("Hello, world!")
* argv.toList foreach Console.println
*
* TODO: It would be better if error output went to stderr instead
* of stdout....
*/
object MainScript {
/** 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 "!#".
*/
val startRegexp = "^(::)?#!.*"
val endRegexp = "^(::)?!#.*"
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.matches(startRegexp)) {
// skip until !# is seen
def lp: Unit = {
val line = file.readLine
if (line == null)
()
else if (!line.matches(endRegexp))
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)")
}
}
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