title: Counting unique values in a column with a shell script
body: <p>I have a tab delimited file with 5 columns and need to retrieve a count of just the number of unique lines from column 2. I would normally do this with Perl/Python but I am forced to use the shell for this one.</p>
  
  <p>I have successfully in the past used *nix uniq function piped to wc but it looks like I am going to have to use awk in here.</p>
  
  <p>Any advice would be greatly appreciated. (I have asked a similar question previously about column checks using awk but this is a little different and I wanted to separate it so if someone in the future has this question this will be here)</p>
  
  <p>Many many thanks!<br>
  Lilly </p>