--- /dev/null
+#!/bin/sh
+
+# Valid environment variables to appear in a planetlab config file
+TAGS='IP_METHOD HOST_NAME DOMAIN_NAME PROXY_SERVER
+ IP_ADDRESS IP_GATEWAY IP_NETMASK IP_NETADDR IP_BROADCASTADDR
+ IP_DNS1 IP_DNS2 NET_DEVICE NODE_KEY NODE_ID
+ IPMI_ADDRESS IPMI_MAC'
+
+# Valid characters that variable can be set to
+CHARS='[:alnum:]\.: _-'
+
+REGEX=''
+
+for t in $TAGS
+do
+ if [ "$REGEX" == "" ]
+ then
+ REGEX="^$t"
+ else
+ REGEX="$REGEX|^$t"
+ fi
+done
+/usr/bin/dos2unix | /bin/egrep "($REGEX)\=\\\"[$CHARS]*\\\"\s*$"