UNIX for Advanced & Expert Users

count=1
val=$2
op=$1
ans=0
if [ $op = "-e" -o $op = "-o" ]
then
        if [ $op = "-e" ]
        then
                while [ $count -le $val ]
                do
                        ans=`expr $count % 2`
                        if [ $ans -eq 0 ]
                        then
                        echo "$count \c "
                        count=`expr $count + 1`
                        fi
                done
        elif [ $op = "-o" ]
        then
                while [ $count -le $val ]
                do
                        ans=`expr $count % 2`
                        if [ $ans -ne 0 ]   
                        then
                        echo "$count \c "
                        count=`expr $count + 1`
                        fi
                done
        fi
else
        while [ $count -le $val ]
        do
                echo "$count \c "
                count=`expr $count + 1`
        done
fi

#!/bin/ksh
count=1 
val=$2 
op=$1 
ans=0 
if [ $op = "-e" -o $op = "-o" ] 
then 
     if [ $op = "-e" ] 
     then 
     while [ $count -le $val ] 
     do 
     ans=`expr $count % 2` 
          if [ $ans -eq 0 ] 
          then 
          echo "$count \c " 
          count=`expr $count + 1` 
          fi 
     done 
     elif [ $op = "-o" ] 
     then 
     while [ $count -le $val ] 
     do 
     ans=`expr $count % 2` 
          if [ $ans -ne 0 ] 
          then 
          echo "$count \c " 
          count=`expr $count + 1` 
          fi 
     done 
     fi 
else 
while [ $count -le $val ] 
do 
echo "$count \c " 
count=`expr $count + 1` 
done 
fi

     if [ $op = "-e" ]                       # This is true in our case
     then 
     while [ $count -le $val ]          # while 1 is less than or equal to 4
     do 
     ans=`expr $count % 2`         # ans = 1 % 2, or ans = 1
          if [ $ans -eq 0 ]                  # if ans (1) = 0, then continue... nope - can't continue
          then 
          echo "$count \c " 
          count=`expr $count + 1` 
          fi                                         # We're done, time to loop while waiting for ans to equal 0

if [ "$op" = "-e" -o "$op" = "-o" ]
echo " if [ $op = -e -o $op = -o ]"
        then
echo "     then"
        if [ "$op" = "-e" ]
echo "     if [ $op = -e ] "
        then
echo "     then"
        while [ "$count" -le "$val" ]
echo "     while [ $count -le $val ] "
        do
echo "     do"
        ans=`expr $count % 2`
echo "     ans=`expr $count % 2` "
                if [ "$ans" -eq "0" ]
echo "          if [ $ans -eq 0 ] "
                then
echo "          then"
                echo -e "$count \c "
echo "          echo -e $count \c"
                count=`expr $count + 1`
echo "          count=`expr $count + 1`"