New To Mapreduce: A Few Questions For Anyone Who Can Help

I am very new to MapReduce.  I have played around with Pig and made some simple examples that work well but Pig’s functionality will most likely not work well for what I need and, unfortunately, from the MapReduce stand point, I
know almost nothing.

I am working within an MPI environment using MapReduce and will be coding in C++.

I am trying to get started on the following two things:

1)      To create a MapReduce program that can run through hundreds of directories, execute a function such as ‘stat’ on every
directory, and then organize that data based on name/size/date/etc and save it
all (preferably to one giant file).

2)      To create a MapReduce program that will run a simple command like ‘ls’ or ‘find –name’ across hundreds of directories.

If anyone could give me advice on where to being researching or how I should begin developing these codes that would be incredible.

Thanks In Advance,

Tyler