title: Why is the output file corrupt / filled with garbage? (Expecting numbers)
body: <p>The following line of code writes unsigned int values into a file but the content of the file is not readable.</p>
  
  <pre><code>struct rabin_polynomial
  {
      uint64_t start;
      uint16_t length;
      struct rabin_polynomial *next_polynomial;   
  };
  
  fprintf(out_file, "%llu,%u",poly-&gt;start,poly-&gt;length);
  </code></pre>
  
  <p>If I display the out put of the code instead to the command line screen it is readable.</p>
  
  <p>the file "out_file" is not opened in binary mode.</p>
  
  <p>Here part of the content of the output file:</p>
  
  <pre><code> -ÍÍÍÍÍÍp\y";^æó r\ ÍÍÍÍ-       ÍÍÍÍÍÍ
  Øâˆ¿»Iðr\ ÍÍÍÍ-      wÍÍÍÍÍÍ7OT-OØÚ‚\ ÍÍÍÍ¤*      L ÍÍÍÍÍÍî›ùçÉç`‚\ ÍÍÍÍð3       ÍÍÍÍÍÍ
  Øâˆ¿»I°‚\ ÍÍÍÍðC       ÍÍÍÍÍÍíK¬è‹Ç{ ƒ\ ÍÍÍÍðS      •   ÍÍÍÍÍÍ-Ló3lJ–ÞPƒ\ ÍÍÍÍ…] 
  </code></pre>
  
  <p>And here is the expected out put:</p>
  
  <pre><code>0,2861 
  2861,4096 
  6957,3959 
  10916,2380 
  13296,4096 
  17392,4096 
  </code></pre>