title: Command required to grep only latest unique MSISDN from data
body: <p>I have one data in which there are 5 fields and all are comma separated. There are two main field infact field 1 is Date in YYYYMMDD format and second field contains MSISDN 10 digits. The file has around 120 million numbers in which some numbers are duplicates, triplicates but the date is differs in that case. </p>
  
  <p>I need only unique MSISDN but the date should be the latest one.</p>