normdate.sh

#!/BIN/BASH
# normate--Normalize month field in date specificaiton to three letters, 
#  first letter capitalized. A helper function for Script #7, valid-date.
#  Exits with 0 if no error.

monthNumToName()
{
  # Sets the 'Month' variable to the appropriate value.
  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="Dev"   ;;
	* ) echo "$0: Unknown Month value $1" >&2
	exit 1
	
esac
return 0
}

# BEGIN MAIN SCRIPT--DELETE OR COMMENT OUT EVERYTHING BELOW THIS LINE IF
# YOU WANT TO INCLUDE THIS IN OTHER SCRIPTS.
# =================
# Input validation

if [ $# -eq 1 ] ; then # to compensate for / or - formats
	set -- $(echo $1 | sed 's/[\/\-]/ /g')
fi

if [ $# -ne 3 ] ; then 
	echo "Usage: $0 month day year" >&2
	echo "Formats are AUgust 3 1962 and 8 3 1962" >&2
	exit 1
fi

if [ $3 -le 99 ] ; then
	echo "$0: expected 4-digit year value." >&2
	exit 1
fi

# Is the month input format a number ?
if [ -z $(echo $1|sed 's/[[:digit:]]//g') ]; then
	monthNumToName $1
else
	# Normalize to first 3 letters, first upper- and then lowercase.
	month="$(echo $1|cut -c1|tr '[:lower:]' '[:upper:]')"
	month="$month$(echo $1|cut -c2-3 | tr ' [:upper:]' ' [:lower:]')"
fi

echo $month $2 $3

exit