diff --git a/ptgctl/tools/display.py b/ptgctl/tools/display.py
index 2bfa329..9355a6a 100644
--- a/ptgctl/tools/display.py
+++ b/ptgctl/tools/display.py
@@ -1,9 +1,12 @@
 '''This contains functions to display values from the API in interesting ways.
 
 '''
+import os
+import contextlib
 import io
 import json as json_
 import time
+import tqdm
 import asyncio
 import datetime
 import numpy as np
@@ -115,6 +118,24 @@ async def raw(api, stream_id, utf=False, **kw):
                     print("could not decode:", data)
 
 
+@util.async2sync
+@util.interruptable
+async def file(api, stream_id, out_dir, include_timestamps=False, **kw):
+    async with api.data_pull_connect(stream_id, **kw) as ws:
+        with contextlib.ExitStack() as stack:
+            files = {}
+            pbars = {}
+            while True:
+                for sid, ts, data in await ws.recv_data():
+                    if sid not in files:
+                        files[sid] = stack.enter_context(open(os.path.join(out_dir, f'{sid}.txt'), 'w'))
+                        pbars[sid] = tqdm.tqdm(desc=sid)
+                    if include_timestamps:
+                        files[sid].write(f'{ts}:')
+                    files[sid].write(f"{data.decode('utf-8')}\n")
+                    pbars[sid].update()
+                    pbars[sid].set_description(f'{sid}: {str(data)[:20]}')
+
 
 @util.async2sync
 @util.interruptable
diff --git a/ptgctl/util/cli.py b/ptgctl/util/cli.py
index 50c31eb..35eeef1 100644
--- a/ptgctl/util/cli.py
+++ b/ptgctl/util/cli.py
@@ -4,6 +4,28 @@
 
 
 
+class CachedProperty:
+    def __init__(self, getattr):
+        super().__init__()
+        self.new = getattr
+        self.key = '__{}'.format(getattr.__name__)
+        self._blank = None
+
+    # Works as a property that instantiates a nested class on first access.
+    # the created instance will be used for subsequent access.
+    def __get__(self, instance, owner=None):
+        if instance is None:
+            if self._blank is None:
+                self._blank = self.new(self)
+            return self._blank
+        try:
+            return getattr(instance, self.key)
+        except AttributeError:
+            x = self.new(instance)
+            setattr(instance, self.key, x)
+            return x
+
+
 class BoundModule:
     '''Acts as a method namespace for a class using a module as the namespace.
     
@@ -96,17 +118,10 @@ def greetings(self):
                     import greetings
                     return greetings
         '''
-        attr = f'__{get_module.__name__}'
-        @property
+        @CachedProperty
         @functools.wraps(get_module)
         def inner(self):
-            # only create the bound module once
-            try:
-                return getattr(self, attr)
-            except AttributeError:
-                bm = cls(self, get_module)
-                setattr(self, attr, bm)
-                return bm
+            return cls(self, get_module)
         return inner
 
 bound_module = BoundModule._bind