Index: tools/rdnap.py
===================================================================
--- tools/rdnap.py	(revision 9809)
+++ tools/rdnap.py	(revision 9822)
@@ -4,8 +4,12 @@
 # longitude : lam
 #
+import os
 import yaml
 import urllib
 
-CACHE_FILE = '/tmp/rd2etrs.yaml'
+try:
+  CACHE_FILE = os.environ['RD2ETRS_CACHE']
+except KeyError:
+  CACHE_FILE = os.path.join(os.environ['HOME'],'.rd2etrs.yaml')
 coordinates = None
 
@@ -18,7 +22,10 @@
 def write_yaml(gfile, datadump):
   """ Write configuration yaml for 'item'"""
-  f = open(gfile, 'w')
-  f.write(yaml.dump(datadump, default_flow_style=False))
-  f.close()
+  try:
+    f = open(gfile, 'w')
+    f.write(yaml.dump(datadump, default_flow_style=False))
+    f.close()
+  except IOError:
+    pass
 
 def etrs2rd(lam, phi):