title: implicit declaration of function 'getch'
body: <p>I have a simple program:</p>
  
  <pre><code>#include &lt;stdio.h&gt;
  #include &lt;stdlib.h&gt;
  
  int main(void){
      printf("Hello world!\n");
  
      getch();
  
      return 0;
  }
  </code></pre>
  
  <p>Even though I get the warning</p>
  
  <pre><code>implicit declaration of function 'getch'
  </code></pre>
  
  <p>the program runs fine. Do I miss something? And if I do, why does the program work OK?</p>