Fibonacci Range [Shell Program]

echo "Enter the
range"

read r

a=0

b=1

c=1

echo "Fibonacci
series:\n"

echo "$a $b
\c"

while [ $c -lt $r ]

do

c=`expr $a + $b`

if [ $c -le $r ]

then

echo "$c \c"

fi

a=$b

b=$c

done

echo "\n"