I want to create a folder name include in-side sites/all/custom/contrib/ and inside this want to write some
.inc files like
string.inc in each file a class is created which holds function.
Now I want to use this functions in each module under sites/all/custom/contrib. I have 10 custom module so this .inc functions are available to each custom module.
What is the directory structure I have to follow and how can I achieve this?