title: Write a function like printf, that can sanitize all arguments after the first to be free from the `%` symbol
body: <pre><code>user_input = "%s%s%s%s%s%s%s%s";
  printf("user input is: %s", user_input);
  </code></pre>
  
  <p>... crash!</p>
  
  <p>The above lines cause an error. I want to write a function which can be used like <code>printf</code> but can sanitize all arguments after the first to make sure they do not contain the <code>%</code> symbol. The function should be used like 'printf' in that it can take any number of arguments and it print outs a string in the same manner. If the other arguments contain the <code>%</code> symbol, I just want that symbol taken out before it is put in the format string.</p>
  
  <p>If this new function were called <code>safe_printf</code>, I would want the behavior to be like this:</p>
  
  <pre><code>user_input = "%s%s%s%s%s%s%s%s";
  safe_printf("user input is: %s, user_input);
  </code></pre>
  
  <p>user input is: ssssssss</p>
  
  <p>It seems like writing a function like this may not be possible, (I can't figure out how to preprocess the char *s in the va_list without knowing how many there are) if that's the case please let me know. Thanks!</p>