If you are using Bash, you are better off using the arithmetic expression, ((...))
for readability and flexibility:
if ((number >= 2 && number <= 5)); then
# your code
fi
To read in a loop until a valid number is entered:
#!/bin/bash
while :; do
read -p "Enter a number between 2 and 5: " number
[[ $number =~ ^[0-9]+$ ]] || { echo "Enter a valid number"; continue; }
if ((number >= 2 && number <= 5)); then
echo "valid number"
break
else
echo "number out of range, try again"
fi
done
((number >= 2 && number <= 5))
can also be written as ((2 <= number <= 5))
.
See also:
- Test whether string is a valid integer
- How to use double or single brackets, parentheses, curly braces