title: fatal error: open.h: No such file or directory
body: <p>I want to use <a href="https://linux.die.net/man/3/open_excl" rel="nofollow noreferrer">open_excl(3)</a> in order to open a file for exclusive writing.</p>
  
  <p>I wrote:</p>
  
  <pre><code>#include &lt;open.h&gt;
  
  int main(int c, char* v[]){
      int fp = open_excl("my_file");
      return 0;
  }
  </code></pre>
  
  <p>Now:
  gcc -Wall file.c -o out.a</p>
  
  <p>And I get a fatal compiler error: open.h: No such file or directory</p>
  
  <p>How come? do I have a broken path problem? Missing a link to a library?
  Wrong version of gcc? I'm using 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.4) </p>