Write a script to enhance the calander to accept any month as mm or mmm or only year as yyyy or both month and year.
if test s# -eq 0 ;then echo "Invalid Arguments"elseif test s# -eq 2;then if $1 -gt 1999 -o $2 -gt 12;then echo "invalid Year or month"else cal $1 $2 ifelseif test s# -eq 1;then if test $1 -gt 12;then cal $1 elsecase $1 in 01) m = jan;; 02) m = feb;; 03) m = mar;; 04) m = apr;; 05) m = may;; 06) m = jun;; 07) m = jul;; 08) m = aug;; 09) m = sep;; 10) m = oct;; 11) m = nov;; 12) m = dec;; esac echo " Calander for $1 Month : " cal $m fi fi