title: Checking if input contains digits only in C
body: <p>I need to check if inserted input (an array which size is determined by user, meaning during run time) contains digits only or not (C99).
  While I have an idea of how to do so, it seems to me to be clumsy which led to me ask here if there's any better solution. My "idea" is to receive the input as an array of strings, and then run with a loop over each member to check if it contains non-digit characters. Is there any way better to do so?</p>