title: Unix/Linux Redirection and piping
body: <p>i am doing an exercise from the book "your Unix/Linux ultimate guide" trying to best learn the command line, this question i was not able to answer after thinking about it for like 45 minutes and the solution is not given in the book, here is the question:</p>
  
  <blockquote>
    <p>Suppose there is an access log file named "access.log" (one entry per line), a filter "userfilter" which only outputs lines in the access log's format corresponding to entries for a user, "roomfilter" which only outputs lines in the access log's format corresponding to entries for a room, and "codefilter" which only outputs lines in the access log's format corresponding to one of either "entry", "exit", or "denied". All of the filters accept one argument to specify the value on which to output. Give a command to display how many times "winston" entered room "101"</p>
  </blockquote>
  
  <p>any help in the right direction will be appreciated, thank you</p>