How to use the Linux let Command

The let command is a tool used in BASH for computing. It is used to execute one or more expressions. You do not need to add $ to variable calculation. If the expression contains spaces or other special characters, it must be caused.

Syntax format

Let arg [arg...]

Parameter description:

Arg: expression to be executed

Instance:

Auto-add operation: let no ++

Auto-subtraction operation: let no --

Let no + = 10 and let no-= 20, which are equivalent to let no = no + 10 and let no = no-20.

The following example calculates the expressions a and B and outputs the results:

#! /Bin/bash

Let a = 5 + 4

Let B = 9-3

Echo $ a $ B

The execution result of the above instance is:

9 6