Shell Programming and Scripting

case $month in
1) month=Jan;;
2) month=Feb;;
:
:

case $month in
[Jj]an) month=1;;
[Ff]eb) month=2;;
:
:

cal `date '+%m'` `date '+%Y'` | grep . | fmt -1 | tail -1

#!/bin/bash

if [ "$1" = "" ]
   then  YEAR=`date '+%Y'`
   else YEAR=$1
fi

MONTH=1
until [ $MONTH -gt 12 ]
      do LASTDAY=`cal $MONTH $YEAR | grep . | fmt -1 | tail -1`
         echo "$MONTH  $LASTDAY"
         let MONTH=$MONTH+1
done