title: How to append to a file using Scheme?
body: <p>I am using TinyScheme (actually Script-Fu in GIMP), and cannot find a good way to open a file and append a line of text to it.</p>
  
  <p>I am trying to log some info to the file for debugging, and transcript-on doesn't seem to be implemented...</p>
  
  <p>Right now I am scraping along by reading the entire file (one character at a time!), concatenating that into a string, concatenating my text to the end of that, then writing it all out to the file again.</p>
  
  <p>There must be a better way!</p>