normdate

#!/bin/bash

function monthNumToName
{
  case $1 in
    1 ) month="Jan" ;;
    2 ) month="Feb" ;;
    3 ) month="Mar" ;;
    4 ) month="Apr" ;;
    5 ) month="May" ;;
    6 ) month="Jun" ;;
    7 ) month="Jul" ;;
    8 ) month="Aug" ;;
    9 ) month="Sep" ;;
    10 ) month="Oct" ;;
    11 ) month="Nov" ;;
    12 ) month="Dec" ;;
    * ) echo "Not valid month: $1" >&2
      exit 1
  esac
  return 0
}

if [ $# -ne 3 ]
then
  echo "$(basename $0): format is Month Day Year" >&2
  echo "valid formats are August 29 1967 and 8 29 1967" >&2
  exit 1
fi

if [ $3 -le 99 ]
then
  echo "Usage $(basename $0): expected 4-digit year format" >&2
  exit 1
fi

if [ -z $(echo $1 | sed 's/[[:digit:]]//g') ]
then
  monthNumToName $1
else
  month="$(echo $1 | cut -c1 | tr '[:lower:]' '[:upper:]')"
  month="$month$(echo $1 | cut -c2-3 | tr '[:upper:]' '[:lower:]')"
fi

echo $month $2 $3

exit 0