Implementing a ReDiS COUNT command in Lua

Inside of a Blog: Implementing a ReDiS COUNT command in Lua: I have recently been implementing a master/slave redis cache for our enterprise application and at certain points during the development/test phases, have found it useful to be able to query redis for the # of keys that have been inserted that match a certain regex...

In short:

eval "return #redis.pcall('keys', '*')" 0