src/Pure/System/system_dialog.scala

 package isabelle
 
 
 import java.awt.{GraphicsEnvironment, Point, Font}
 import javax.swing.WindowConstants
+import java.io.{File => JFile, BufferedReader, InputStreamReader}
 
 import scala.swing.{ScrollPane, Button, CheckBox, FlowPanel,
   BorderPanel, Frame, TextArea, Component, Label}
 import scala.swing.event.ButtonClicked
 

     try { result.fulfill(_return_code.get) }
     catch { case ERROR(_) => }
   }
 
   def join(): Int = result.join
+  def join_exit(): Nothing = sys.exit(join)
 
 
   /* window */
 
   private class Window extends Frame

   override def theory(session: String, theory: String): Unit =
     echo(session + ": theory " + theory)
 
   @volatile private var is_stopped = false
   override def stopped: Boolean = is_stopped
+
+
+  /* system operations */
+
+  def execute(cwd: JFile, env: Map[String, String], args: String*): Int =
+  {
+    val proc = Isabelle_System.raw_execute(cwd, env, true, args: _*)
+    proc.getOutputStream.close
+
+    val stdout = new BufferedReader(new InputStreamReader(proc.getInputStream, UTF8.charset))
+    try {
+      var line = stdout.readLine
+      while (line != null) {
+        echo(line)
+        line = stdout.readLine
+      }
+    }
+    finally { stdout.close }
+
+    proc.waitFor
+  }
 }