title: Reading fwf file with no given columns and uneven "width" for subject rows
body: <p>I'm only a beginner and I’m trying to read a fwf file that looks like this (The rows have the same number of entries):</p>
  
  <pre><code>02291111121331321132321131311332322333333111111131111331322332322131111111111111111                                             
  0229208050122132321      122211331322233322333333111111333333333333133321333321333333333322                                     
  02293            08050122133111121111     08050122’…ƒ Ž”’Œ)‹”˜ ‘€(                                                           
  02301333331111111333332332332      333333333331333333111111111112331311332311111111                                             
  0230208050105333331131211333333112111123321233333231311333333333333333333112111333332123311                                     
  02303            080501051133221355212    08050105€€ ™Œ… ’…ƒ ‡‰”„ Ž‚˜™
  </code></pre>
  
  <p>Every three rows stand for a subject (first four entries= "subject.id").
  Every subject answered three questioners (5th entry= “questionnaire.number”) and each questionnaire has different widths. 
  I have an index for each questionnaire but i can’t find a way to assign the widths to the 1st row, 4th row, 7th row; 2nd row, 5th row, 8th row; 3rd row, 6th row, 9th row etc.)
  Total amount of rows=7140. </p>
  
  <p>Hope i was able to explain the problem in an understandable way. 
  Any help will be great.</p>