title: The Length of envp in C
body: <p>In the proccess of learning C, I'm trying to write a program that accepts one of your environment variable as input, and outputs its value.</p>
  
  <p>The question is, is there any way to know the length of envp? I mean, how many envp is there? I'm aware that it is a char** - an array of string. And <a href="https://stackoverflow.com/questions/2089071/array-length-in-c">finding the size of array in C is problematic</a> already. What can I do to know the size of envp?</p>
  
  <p>Please just provide direction, not the concrete answer (or code).</p>