Clipboard operations: xclip or pbcopy/pbpaste style operations.

amm/repl/src/main/scala/ammonite/repl/ApiImpls.scala

@@ -1,10 +1,13 @@
 package ammonite.repl
 
-
+import ammonite.ops.Internals
 import ammonite.runtime._
 import ammonite.util.Util._
 import ammonite.util._
 
+import java.awt.Toolkit
+import java.awt.datatransfer.{DataFlavor, StringSelection}
+
 import scala.collection.mutable
 
 class SessionApiImpl(frames0: => StableRef[List[Frame]]) extends Session{
@@ -108,4 +111,26 @@ trait ReplApiImpl extends FullReplAPI{
 
   def sess: SessionApiImpl
 
+  override def clipboard: Clipboard = ClipboardImpl
+}
+object ClipboardImpl extends Clipboard {
+
+  private lazy val systemClipboard =
+    Toolkit.getDefaultToolkit.getSystemClipboard
+
+  override def read: String =
+    Option(systemClipboard.getContents(null)) collect {
+      case data if data.isDataFlavorSupported(DataFlavor.stringFlavor) =>
+        data.getTransferData(DataFlavor.stringFlavor)
+    } match {
+      case Some(str: String) => str
+      case _ => ""
+    }
+
+  override def write(data: Internals.Writable): Unit = {
+    val newContents = new StringSelection(
+      data.writeableData.map(new String(_)).mkString
+    )
+    systemClipboard.setContents(newContents, newContents)
+  }
 }

amm/repl/src/main/scala/ammonite/repl/ReplAPI.scala

@@ -1,5 +1,6 @@
 package ammonite.repl
 
+import ammonite.ops.Internals
 import ammonite.util._
 
 import scala.reflect.runtime.universe._
@@ -160,6 +161,8 @@ trait ReplAPI {
   def sess: Session
 
   def load: ReplLoad
+
+  def clipboard: Clipboard
 }
 trait ReplLoad{
   /**
@@ -206,4 +209,17 @@ trait Session{
     */
   def delete(name: String): Unit
 }
-
+trait Clipboard{
+  /**
+    * Reads contents from the system clipboard.
+    * @return System clipboard contents if they are readable as `String`,
+    *         empty string otherwise.
+    */
+  def read: String
+  /**
+    * Sets the contents of the system clipboard.
+    *
+    * @param data New contents for the clipboard.
+    */
+  def write(data: Internals.Writable): Unit
+}

amm/repl/src/test/scala/ammonite/unit/ClipboardTests.scala

@@ -0,0 +1,32 @@
+package ammonite.unit
+
+import ammonite.repl.{Clipboard, ClipboardImpl}
+
+import java.awt.Toolkit
+import java.awt.datatransfer.DataFlavor
+
+import utest._
+
+object ClipboardTests extends TestSuite{
+
+  val clipboard: Clipboard = ClipboardImpl
+
+  val canTest = Toolkit.getDefaultToolkit.getSystemClipboard.isDataFlavorAvailable(
+    DataFlavor.stringFlavor
+  )
+
+  override def tests = Tests {
+    println("ClipboardTests")
+    'clipboard {
+      val newClipboardContents = "hello Ammonite"
+      'copyandpaste - {
+        if (canTest) {
+          clipboard.write(newClipboardContents)
+          assert(clipboard.read == newClipboardContents)
+        } else {
+          println("The environment doesn't allow testing clipboard operations - skipping")
+        }
+      }
+    }
+  }
+}