Question

What’s wrong I get an error : ./greater[4]: [: argument expected

#!/bin/ksh
echo "please enter a nuber " 
read $num
if [$num -ls 20 ]; then
 echo "your nuber is greater than 20 "
else
echo "your number is less then 20 "

 fi

Answer 1

read $num

That above will read input into a variable which name is stored in $num, which “obviously” isn’t correct. Change it to read num and it will work as expected.

---

With the above change you’ll also need to add a space after [ on the line quoted below:

if [$num -ls 20 ]; then

Otherwise the command will look like the below code-snippet if the user enters 123, and your shell will complain about the command [123 isn’t found, or similar.

if [123 -ls 20 ]; then