How to batch rename files and folders to shorten their length?

Dear all,

I'm facing the following need: in order to make a folder compliant with the requisites of Microsoft OneDrive, I need to rename files and folders to shorten their length.

The main requisite is that the whole path (i.e. ~/folder-name/file-name.file should not exceed 250 characters).

I would like to know if OS X (Yosemite in my case) has some tools to accomplish this task or if I can find something free online.

Many thanks.