title: Makefiles to include multiple headers in c
body: <p>I originally had this in my makefile:</p>
  
  <pre><code>all:
      gcc myFunctions1.h myFunctions1.c myFunctions2.h myFunctions2.c main.c -o main
  </code></pre>
  
  <p>which worked for some reason until I restarted the terminal. Now I get this error:</p>
  
  <pre><code>clang: error: cannot specify -o when generating multiple output files
  </code></pre>
  
  <p>So what's the proper way to do this? </p>