title: Fill remainder of line with spaces to hit fixed width
body: <p>I have some plaintext data files that should be fixed width and space delimited.  However, the far right-hand columns are rarely populated and for those rows with missing values the row's text stops at the last populated column.  Since the characters cease the file isn't really fixed width and there aren't any delimiters or missing symbols (NAs).</p>
  
  <p>When I examine the headers I see that the maximal row structure would be</p>
  
  <ul>
  <li><p>17 columns with 16 spaces</p></li>
  <li><p>77 char for data giving fixed width of 93 including delimiters</p></li>
  <li><p>Column structure of (4,2,2,2,2,5,5,3,8,5,7,4,4,6,6,6,6)</p></li>
  </ul>
  
  <p>What I'd like to do is add 93-POPULATED_LENGTH spaces to the end of each line so that I can parse it as fixed width for data analysis.  A solution in Bash or lightweight Python would be ideal.</p>