title: Bash sort files by filename containing year and abbreviated month
body: <p>I have files for many years and all months, with example names: <code>dir1/dir2/dir3/file_name_2017_v_2017.Jan.exp.var.txt</code>, <code>dir1/dir2/dir3/file_name_2017_v_2017.Feb.exp.var.txt</code>, …, and <code>dir1/dir2/dir3/file_name_2017_v_2017.Dec.exp.var.txt</code>.</p>
  
  <p>There is a script executing a one line command to store a list of files in an array.</p>
  
  <pre><code>ls dir1/dir2/dir3/file_name_2017_v_*.exp.var.txt
  </code></pre>
  
  <p>This works, however they are out of order by month.  I would like them to be sorted by YYYY.MMM.  I have tried various sort commands using -M to lastly sort by month, however nothing is working.  What am I missing to sort these files?  I prefer a one-line command to sort these.</p>
  
  <p>Edit 1:
  Using ls *.txt | sort --field-separator='.' -k 1,2M -r reverses the year order, and the alphabetical order of the months.  Removing the -r puts the years in chronological order, however the months are in alphabetical order.  This is not what I want, as I want the files in chronological order</p>