Shell Programming and Scripting

# if you give 1 input, then xstr is empty, if you give more than one then extra values 
# is in var xstr. This is the easiest way to read N variables, read N+1 variables, last var 
# include all extra data
read var xstr
[ "$xstr" != "" ] && echo "too many values" && exit 1
echo $var

#!/usr/bin/bash

echo enter variables
read INPUT
WORDS=`echo $INPUT | wc -w`

case $WORDS in
        1)
                echo one variable found
                ;;
        2)
                echo TWO variables found
                ;;
        *)
                echo ERROR: Incorrect number of variables supplied
                exit 1
                ;;
        esac

while getopts() s: d: m:
do
case $(VAR) in 
S) Single=${OPTARG};;
D) Double=${OPTARG};;
*) Multiple=ERR;;
esac
done

suppose ur scirpt name is Krame.ksh then shud call like this
eg:-
1) Krame.ksh -S {ur single input}
2) krame.ksh -S {single input} -D {Second input}
3) krame.ksh -S (something) -D (anythin) -S (smthng again) = this wil throw error

 
#!/usr/bin/ksh

read a b

if [ ! -z "$a" ]&&[ ! -z "$b" ]; then
echo "two"
elif [ ! -z "$a" ] || [ ! -z "$b" ] ; then
echo "one"
else
echo "oops!!!, both are empty"
fi