diff --git a/panda/src/express/Sources.pp b/panda/src/express/Sources.pp
index b59899e6cf..dec8e3e53f 100644
--- a/panda/src/express/Sources.pp
+++ b/panda/src/express/Sources.pp
@@ -14,6 +14,7 @@
     circBuffer.h \
     config_express.h \
     compress_string.h \
+    copy_stream.h \
     datagram.I datagram.h datagramGenerator.I \
     datagramGenerator.h \
     datagramIterator.I datagramIterator.h datagramSink.I datagramSink.h \
@@ -74,6 +75,7 @@
     buffer.cxx checksumHashGenerator.cxx \
     config_express.cxx \
     compress_string.cxx \
+    copy_stream.cxx \
     datagram.cxx datagramGenerator.cxx \
     datagramIterator.cxx \
     datagramSink.cxx dcast.cxx \
@@ -125,6 +127,7 @@
     circBuffer.h \
     config_express.h \
     compress_string.h \
+    copy_stream.h \
     datagram.I datagram.h datagramGenerator.I \
     datagramGenerator.h \
     datagramIterator.I datagramIterator.h datagramSink.I datagramSink.h \
diff --git a/panda/src/express/copy_stream.cxx b/panda/src/express/copy_stream.cxx
new file mode 100755
index 0000000000..7902716258
--- /dev/null
+++ b/panda/src/express/copy_stream.cxx
@@ -0,0 +1,39 @@
+// Filename: copy_stream.cxx
+// Created by:  drose (27Aug09)
+//
+////////////////////////////////////////////////////////////////////
+//
+// PANDA 3D SOFTWARE
+// Copyright (c) Carnegie Mellon University.  All rights reserved.
+//
+// All use of this software is subject to the terms of the revised BSD
+// license.  You should have received a copy of this license along
+// with this source code in a file named "LICENSE."
+//
+////////////////////////////////////////////////////////////////////
+
+#include "copy_stream.h"
+
+////////////////////////////////////////////////////////////////////
+//     Function: copy_stream
+//       Access: Published
+//  Description: Reads the source stream from its current position to
+//               the end of the stream, and writes that data to the
+//               dest stream at its current position.  Returns true on
+//               success, false on failure.
+////////////////////////////////////////////////////////////////////
+bool
+copy_stream(istream &source, ostream &dest) {
+  static const size_t buffer_size = 4096;
+  char buffer[buffer_size];
+
+  source.read(buffer, buffer_size);
+  size_t count = source.gcount();
+  while (count != 0) {
+    dest.write(buffer, count);
+    source.read(buffer, buffer_size);
+    count = source.gcount();
+  }
+  
+  return (!source.fail() || source.eof()) && (!dest.fail());
+}
diff --git a/panda/src/express/copy_stream.h b/panda/src/express/copy_stream.h
new file mode 100755
index 0000000000..6e2274aa4e
--- /dev/null
+++ b/panda/src/express/copy_stream.h
@@ -0,0 +1,25 @@
+// Filename: copy_stream.h
+// Created by:  drose (27Aug09)
+//
+////////////////////////////////////////////////////////////////////
+//
+// PANDA 3D SOFTWARE
+// Copyright (c) Carnegie Mellon University.  All rights reserved.
+//
+// All use of this software is subject to the terms of the revised BSD
+// license.  You should have received a copy of this license along
+// with this source code in a file named "LICENSE."
+//
+////////////////////////////////////////////////////////////////////
+
+#ifndef COPY_STREAM_H
+#define COPY_STREAM_H
+
+#include "pandabase.h"
+
+BEGIN_PUBLISH
+EXPCL_PANDAEXPRESS bool
+copy_stream(istream &source, ostream &dest);
+END_PUBLISH
+
+#endif
diff --git a/panda/src/express/express_composite1.cxx b/panda/src/express/express_composite1.cxx
index e92102d38d..19ac8a0c56 100644
--- a/panda/src/express/express_composite1.cxx
+++ b/panda/src/express/express_composite1.cxx
@@ -2,6 +2,7 @@
 #include "checksumHashGenerator.cxx"
 #include "config_express.cxx"
 #include "compress_string.cxx"
+#include "copy_stream.cxx"
 #include "datagram.cxx"
 #include "datagramGenerator.cxx"
 #include "datagramIterator.cxx"