In shell scripting, mathematical expressions can be evaluated using the expr command or the $((...)) notation.
The expr command is used to evaluate mathematical expressions and return the result. The expression must be enclosed in quotes and can include operators such as +, -, *, /, and % for addition, subtraction, multiplication, division, and modulus, respectively. For example:
result=$(expr 2 + 2)
echo "The result is $result"
Alternatively, you can use the $((...)) notation to evaluate mathematical expressions. This notation is more concise and easier to read than the expr command. For example:
result=$((2 + 2))
echo "The result is $result"
You can also use the let command:
Copy codelet result=2+2
echo "The result is $result"
You can also use the double paranthesis for more complex mathematical expressions. For example:
result=$(( (2 + 2) * (3 - 1) / 2 ))
echo "The result is $result"
You can also use the more advanced command like awk or bc for more complex mathematical operations.
Keep in mind that the expr command and the $((...)) notation can only handle integers and not floating point numbers, if you need to deal with floating point numbers then you can use commands like bc or awk for more complex mathematical operations.