title: What C++ library do I need to get this program to compile
body: <p>When I try to compile my program I get these errors:</p>
  
  <pre><code>btio.c:19: error: ‘O_RDWR’ was not declared in this scope
  btio.c:19: error: ‘open’ was not declared in this scope
  btio.c: In function ‘short int create_tree()’:
  btio.c:56: error: ‘creat’ was not declared in this scope
  btio.c: In function ‘short int create_tree(int, int)’:
  btio.c:71: error: ‘creat’ was not declared in this scope
  </code></pre>
  
  <p>what library do I need to include to fix these errors?</p>