title: How can I share an array between the C files of a library, without the array being visible to the outside?
body: <h2>Context</h2>
  
  <p>I am in the process of writing a small library in C for an embedded system. The library is at the moment fairly small, but I would like to implement a nice structure for the library from the beginning on. At the moment i have split the implementations of the prototypes into several c files, but I only have one header file.</p>
  
  <h2>Problem</h2>
  
  <p>In this library I need a number of arrays of structs that are visible to the different c files of the library, but invisible to the user of the library.
  How can I share an array between the C files of a library, without the array being visible to the outside?</p>