Bash math. Bash is a straightforward language to learn.

Bash math " Two shells that do support float math are ksh and zsh. These operations can be used to increment a counter, calculate percentages or totals, or determine if a number is even or odd. May 4, 2024 · The mod operator in Bash is used to find the remainder of a division. It is. Jul 18, 2022 · The Linux bash, also known as the shell or just the command line, lets you perform both basic and complex arithmetic and boolean operations without the need to start a calculator app. See examples of integer and floating-point arithmetic, exponentiation, and modulus operations. Explore syntax, practical examples, and best practices for performing Bash Modulo for remainder calculations using arithmetic expansion and expr. How long can you survive? You'll need to complete a few actions and gain 15 reputation points before being able to upvote. bash $ . Sep 26, 2020 · My previous post Performing Math Calculation in Bash was an introduction to elementary arithmetic operations (addition, subtraction, division, multiplication) in a bash shell or by using bc. Mar 31, 2010 · echo 3+3 How can I evaluate such expressions in Bash, in this case to 6? Jan 16, 2024 · This article mainly talks about Bash arithmetic. Learn setup tips and practical uses in data manipulation and automation, enhancing quick AI prototyping. Apr 26, 2025 · Bash is a powerful scripting language that can be used for a variety of tasks, including mathematical calculations. Learn how to perform basic arithmetic operations in Bash scripting using different methods such as let, expr, and double parentheses. I have the variable "total", which consists of a few numbers separated by spaces, and I want to calculate the Learn the essentials of utilizing the `bc` command for arithmetic in Bash, focusing on floating-point calculations not supported by Bash's default integer arithmetic. Basic arithmetic operations are necessary for many automation jobs, including converting the CPU temperature to Fahrenheit. Apr 14, 2022 · Learn how to do basic and advanced math in Bash scripting with various commands and methods. $ ( ( )) is the first example of a math context, meaning a context where the syntax and semantics of C's integer arithmetic are used. Feb 2, 2010 · In Bash, test and [ are shell builtins. Doing something like that in bash is a bit of a bear. You can find many options to perform arithmetic operations on bash shell but below example will provide you simplest way. Basic Arithmetic With expr The expr command can evaluate simple integer […] Perform arithmetic operations ← Getting User Input Via Keyboard • Home • Create an integer variable → You can perform math operations on Bash shell variables. bash calculateIntroduction Mathematical and arithmetic operations are essential in Bash scripting. Understanding the precise differenes and appropriate use cases of ( ( )) and $ ( ( )) can enable more efficient and cleaner bash coding. These include double parentheses, and the let and expr commands. In this comprehensive guide, we‘ll explore how to unleash the full power of expr in your Bash scripts. The most obvious command for doing math on the Linux command line is expr as in “expression”. Arithmetic expansions may be nested. Oct 4, 2023 · Here are all the test operators available in bash. Introduction Bash, the powerful shell scripting language, offers a wide range of features for performing arithmetic operations. Feb 28, 2024 · Summary Bash includes a set of operators such as arithmetic, relational, logical, bitwise, assignment, and ternary operators. What is the correct syntax? #!/usr/bin/env bash FIRSTV=`ls -1 | wc -l` cd . Jul 23, 2025 · In this article, we will see arithmetic operators in bash script. See examples, syntax, and tips for each method. Sep 22, 2025 · Learn to use Bash operators in Linux scripting. Play Electron Dash at Math Playground!Use arrow keys on your keyboard or screen to conrol your intergalactic space runner. net, fix the errors or come back here with specific issues that you can't resolve. Jun 14, 2013 · Using echo "20+5" literally produces the text " 20+5 ". Bash Arithmetic Operations You can perform arithmetic operations on numeric values in bash scripts. Here’s a simple example: Sep 22, 2025 · Master Bash arithmetic operations with this tutorial. Learn how to perform arithmetic operations in Bash scripting. I was wondering, is it possible to do simple maths in bash? I'm thinking something like, =25-5 would print out 20 or something. These include addition, subtraction, multiplication, division, modulus, incrementing, decrementing, and exponentiation. sh). 5 Shell Arithmetic ¶ The shell allows arithmetic expressions to be evaluated, as one of the shell expansions or by using the (( compound command, the let and declare builtins, the arithmetic for command, the [[ conditional command, or the -i option to the declare builtin. Bash calls this an "Arithmetic Expansion", and it obeys the same basic rules as all other $ substitutions. Ideal for developers. This guide teaches you how to do basic math in Bash in various ways. Bash is a straightforward language to learn. 0)) prints 0 : (. with two decimals: Jul 12, 2012 · I'm quite new to bash scripting and usually avoid it all costs but I need to write a bash script to execute some simple things on a remote cluster. Nov 3, 2023 · As a Linux system administrator, developer or power user, you‘ll inevitably need to perform basic math in Bash scripts and at the command line. c² = a² + b² You should recognize that as the Pythagorean formula representing the sides of a right-angled triangle. Jul 3, 2023 · In the fourth chapter of the series, learn to use basic mathematics in Bash. If you want one decimal place of precision, $((1*80/10)) returns 8, which gives you the integer part of (10* number) for you to do with what you will. A shell variable need not have its integer attribute turned on to be used in an expression. Dec 18, 2024 · Bash math refers to mathematical operations you can conduct on the command line in Linux. The following menu breaks the features up into categories, noting which features were inspired by other shells and which are specific to Bash. Discover the power of bash bc for quick calculations. Bash provides several methods to carry out math calculations in your scripts. In this article, I will talk about different arithmetic operators with their execution in Bash. 8 gets truncated to 0. A leading '0x' or '0X' denotes hexadecimal. The format for arithmetic expansion is: $((expression)) Nov 8, 2024 · Master bash floating point math effortlessly with our concise guide, unlocking powerful calculations for your scripts and boosting your productivity. Discover arithmetic, string, and file testing in simple steps. Master the art of calculations with bash calculate. There are a few common ways to perform mathematical operations on numbers in bash. Sep 5, 2022 · This guide explains the different ways and tools to perform arithmetic operations in Bash shell scripting with examples. However, with the help of various tools and utilities, Bash can perform floating-point calculations effectively. The test and [ commands determine their behavior based on the number of arguments; see the descriptions of those commands for any other command-specific Simple math functions for bash. bash 224 224 is evenly divisible by 4 $ . Apr 26, 2025 · Using expr for Math Calculations The expr command is a built-in tool in Bash that can be used to perform arithmetic operations. Each test operator's usage is explained with practical examples. Learn to perform calculations, use external tools, and apply arithmetic in Bash scripting. I am looking for answers using either the basic command shell ('command line') itself or through using languages that are available from the command line. Master the art of bash math with this concise guide. Includes syntax, examples, and best practices for reliable arithmetic operations. In addition to bc, you can use dc, AWK, Python, Perl and others from within a Bash script. Basic Math Bash has some built-in functionality for really basic integer math, like addition, subtraction, multiplication, and division. You can also use external command such as expr and bc calculator. The syntax you can use inside $(( )) (and a few other other "arithmetic" contexts) is very different from what you can use elsewhere. Jul 17, 2010 · 1 I found the previous answers helpful when trying to perform floating point arithmetic on numbers in a pipe. It is primarily used to perform basic arithmetic operations, such as addition, subtraction, multiplication, and division. Jul 31, 2016 · You'll need to complete a few actions and gain 15 reputation points before being able to upvote. For a quick overview of the Arithmetic Operations in Bash, you may refer Bash Arithmetic Operations. It has some surprising uses. This concise guide unveils essential techniques for mastering calculation and logic in your scripts. So, now that I've figured it out, let's just jump straight to it: How to Bash Arithmetic Expansion allows you to perform arithmetic operations within your Bash scripts. This comprehensive guide covers simple to complex operations, including mathematical functions and conditional logic, alongside best practices for precision control and interactive calculations. KornShell arithmetic may be helpful. By mastering the use of double parentheses, you can write more expressive and efficient Bash scripts. Performing arithmetic or mathematical operations is possible in bash, but is a bit limited and cumbersome. Bash uses the value formed by expanding the rest of parameter as the new parameter; this new parameter is then expanded and that value is used in the rest of the expansion, rather than the expansion of the Regarding the use of bc for floating point arithmetic, it or something similar is required when using Bash and many other shells. Watch out for laser beams and openings in the tunnel floor. Explore Bash's adeptness in mathematical computations, useful for web developers and system administrators involved in AI projects. While Bash does not support floats natively, there are methods to emulate float math and percentage calculations. In this tutorial, we’ll guide you through the different methods of performing addition in Bash with detailed examples and scenarios. Ideal for both novice and Jan 16, 2024 · Arithmetic operators are operators that facilitate the evaluation of a desired mathematical expression. This is because the asterisk on it’s own is a wildcard in Bash/Zsh, ie it means ‘everything’ as opposed to ‘multiplication’. Jan 9, 2019 · In this article, we will show you various useful ways of doing basic arithmetic's or mathematical calculations in the Linux terminal using command-line tools. This guide teaches you how to do basic math in Bash in several ways. Dec 27, 2024 · Instead of constantly switching between applications, you can leverage the Linux terminal for a wide range of handy calculations – from basic arithmetic to advanced statistics and visualization. @AaronFranke math in bash only works with integers, it doesn't do floating point or decimals. Jun 16, 2025 · Introduction Math and arithmetic operations are essential in Bash scripting. The Advantages of Keeping Math in the Terminal Here are some May 8, 2025 · With the right math command, you can do anything from simple to fairly complex calculations on Linux. Thus, you can just set SECONDS to 0 before starting the timed event, simply read SECONDS after the event The result is treated as the arithmetic expression to be evaluated. Start with something simple Moved PermanentlyThe document has moved here. Dec 4, 2023 · So, let’s dive in and start mastering Bash Math! TL;DR: How Do I Perform Math in Bash? To perform math in bash, you can use the $(( )) syntax. Includes syntax, examples, and best practices for accurate Bash scripting. I have this Bash script and I had a problem in line 16. In this tutorial we will be discussing about using mathematical operations in our scripts. Understanding Bash Operators This section provides an overview of operators used in Bash scripting, including comparison, string, arithmetic, logical, and file test operators. This guide simplifies arithmetic with examples and tips to enhance your scripting skills. These operators allow for mathematical computations, condition evaluations, expression combinations, bit manipulations, value assignments, and conditional ternary expressions within Bash scripts. Also, in a simple test, double square brackets seem to evaluate quite a lot quicker than single ones. Bash provides several ways to perform arithmetic operations and calculations in your shell scripts. Bash script supports 11 arithmetic operators. The commands like expr, jot, bc and, factor etc, help you in finding optimal mathematical solutions to complex problems. Apr 27, 2021 · Math is easy, Bash scripting is easy, so performing math/arithmetic in Bash/Shell scripts should be easy too. $ chmod +x trymod4. I'm using a serial terminal to provide input into our lab experiment. Arithmetic operators is used to perform arithmetic operations. Bash is a command-line shell used in many Unix-based systems, including Linux and macOS. Here's how to do it. Dec 23, 2021 · Paste your code into shellcheck. This guide simplifies the process, showcasing essential commands for quick calculations in your scripts. However, working with numbers in Bash can be challenging, especially when dealing with floating-point arithmetic, large numbers, and complex calculations. The double bracket [[, which is a shell keyword, enables additional functionality. In this tutorial, we will dive into the world of bash arithmetic, exploring the basic operators and delving into more advanced techniques to enhance your shell programming skills. Oct 14, 2012 · Note that you'll convert one textual representation into another via floating-point arithmetic, which is subject to the same rounding errors as the awk and perl approaches. May 1, 2025 · In Part 5 of our shell scripting tutorial, learn to calculate Fibonacci numbers and convert between decimal, binary, octal, and hexadecimal in Bash. 4 Bash Conditional Expressions ¶ Conditional expressions are used by the [[ compound command (see Conditional Constructs) and the test and [ builtin commands (see Bourne Shell Builtins). Created by Brian Fox in 1989 as a free replacement for the Bourne Shell, Bash focused primarily on command execution and scripting. sh to show how we can increment an integer variable using the let command: Dec 8, 2014 · $(command) is 'command substitution', it runs the command, captures its output and inserts it into the command line that contains the $ (…) bc -l is calculating the expression and giving the result upto 20 decimal places printf %. Within an expression, shell variables may also be referenced by name without using the parameter expansion syntax. The value of a variable is evaluated as an arithmetic expression when it is referenced. Implementing mathematical operations in Bash is simple and very easy to learn. Jan 20, 2022 · The Bash let command allows you to evaluate arithmetic expressions in the Bash shell. I found that using $ echo "5X5" just returns a string of "5X5". See Arithmetic Expansion and Shell Arithmetic in the Bash Reference Manual for all the gory details. Apr 8, 2017 · Bash has a handy SECONDS builtin variable that tracks the number of seconds that have passed since the shell was started. We look at a few ways to execute these calculations inside and outside of the shell itself. Jul 22, 2020 · We often need to perform numeric calculations in our bash scripts. I have the script below to subtract the counts of files between two directories but the COUNT= expression does not work. Various automation tasks require basic arithmetic operations, such as converting the CPU temperature to Fahrenheit. This guide will show you how to perform basic and advanced calculations using different arithmetic operators and Learn how to perform subtraction in Bash scripting with various methods like arithmetic expansion, expr, let, and bc for floating-point numbers. Can this be done easily? Thank you What is the difference between =, == and -eq in shell scripting? Is there any difference between the following? Jan 19, 2023 · Introduction: Bash Math Operations and How They Help in Scripting In Bash scripting, Bash Math Operations are Explained, and arithmetic operations are crucial. However, over the years, it has evolved to include basic arithmetic capabilities. And of course a b c are variables. Math in bash: how to use all bash operators (+, -, /, *, **, &, &&, <<, etc. Performing math operations in Bash is a bit different than on other platforms, so it may prevent some future confusion if you learn about these things now. For example, to add two numbers together using expr, you can use the following command:. Is there a command to execute a multiplication operation? Multiplication needs to have a backslash before the *. /trymod4. Learning to do Math in scripting is crucial feature as we must know how we manipulate numbers in BASH Scripting. Don't let your familiarity with the Bash shell stop you from exploring other options. 3f is taking floating number where . "| bc" seems to be working quite fine, so no need of a new shell. First thing is to put #!/bin/bash as the first line, which declares that it's a bash shell script. Contribute to samedog/bash-math development by creating an account on GitHub. Discover tips, tricks, and commands to perform quick computations seamlessly. Basic Arithmetic in Bash A simple […] Apr 26, 2025 · Welcome to “Mastering Arithmetic Operators in Bash: A Comprehensive Guide,” a resource dedicated to providing an in-depth understanding of arithmetic operators in the powerful and versatile Bash shell. Since the way Bash handles double quotes can potentially result in empty strings, arithmetic expansion treats those as expressions that evaluate to 0. This guide reveals how Bash, beyond its basic arithmetic functions, utilizes tools like `bc` for advanced calculations essential in AI-driven tasks. These truncation errors are specifically why I included the proviso "if you don't need a lot of precision" in my answer. Our easy-to-follow, step-by-step guides will teach you everything you need to know about Bash Arithmetic Operators. Bash built-in arithmetic works with integers only, so when you do division it discards the decimal portion of the result (or the remainder if you prefer) meaning your result is always "rounded down". Feb 25, 2019 · I lived with bash for 9 years, I don't wanna start learning a new shell, just for a math function. Some of the shells that Bash has borrowed concepts from are the Bourne Shell (sh), the Korn Shell (ksh), and the C-shell (csh and its successor, tcsh). As someone who often works with data and performs data analysis tasks, being able to do math directly in Bash has been a real time-saver for me. See examples of arithmetic expansion, awk, bc, dc, declare, expr, and more. Jan 17, 2024 · Learn how to use arithmetic expansion to calculate numbers in your shell scripts. This bash tutorial describes how to perform integer arithmetic or floating point math operations in a bash shell script. This article talks about few practical usages of mod operator. Apr 26, 2025 · Conclusion Double parentheses ( (…)) in Bash provide a powerful and concise way to perform arithmetic operations, evaluate expressions, and control the flow of your script. As a general rule, shell syntax is extremely context-dependent. What command can I use to get the numeric sum, 25 in this case? Also, what's the easiest way to do it just using bash for floating point? For example, echo $((3224/3807. All the operators with their uses is given below: The result is second operand raised to the power of first operand. It works with arithmetic expressions and provides nearly instant responses to your requests even I need to do date arithmetic in Unix shell scripts that I use to control the execution of third party programs. Upvoting indicates when questions and answers are useful. Dec 5, 2024 · Bash provides several ways to perform arithmetic operations in shell scripts. Discover syntax, examples, and best practices for mathematical calculations in Bash. bash 223 223 is NOT evenly divisible by 4 I put this in, because you used the single [ ] conditional, which I usually associate with sh -compatible programs. One can perform simple addition, and subtraction and evaluate complex arithmetic expressions using these operators. This article will cover May 26, 2025 · The Power and Limitations of Bash for Calculations Bash (Bourne Again SHell) wasn‘t originally designed as a calculation powerhouse. Implementing math operations in Bash is simple and very easy to learn. Sep 20, 2023 · Learn how to use the modulo operator in Bash scripting to perform arithmetic operations and assignments. 9k of them just want the title of this question answered 😃: Even I googled "bash modulus" looking for that answer, and landed here. A Nov 23, 2014 · After bash does arithmetic substitution, that command looks like: Var1= 50 That command says (a) temporarily set Var1 to empty, and (b) run the command named 50. I'm having problems with a for loop that does the I am having troubles with the arithmetic expressions in a bash file (a unix file . A shell variable that is null or unset evaluates to 0 when referenced by name without using the parameter expansion Sep 21, 2025 · Learn various arithmetic operations in Bash scripts on Linux using double parentheses, bc, let, expr, and awk. Hello Linux-fanatics, this is my 4 th tutorial in BASH Scripting series (other tutorials are HERE). POSIX says that "Only signed long integer arithmetic is required. I'm using a function to increment a day and another to decrement: IncrementaDia() @Anonymous Bash doesn't support floats in any native way, so you'll have to either use non-portable solutions like bc or make some clever hacks like separating the int/decimal parts and comparing them separately. The expr command in Bash allows you to evaluate expressions and return results. Mar 26, 2025 · The let command is a built-in Bash command to evaluate arithmetic expressions. . g. But how exactly do you add, subtract, multiply and divide numbers within Bash? The default Unix shell provides multiple built-in ways to handle arithmetic operations. From simple integer math to advanced […] Learn how to do arithmetic in Bash, use bc for decimals, and handle number operations right from the terminal. May 8, 2024 · Doing math in Bash is a useful skill to have, especially when working with numbers and performing calculations on the command line. The evaluation is performed according to the rules listed below (see Shell Arithmetic). Pete shows you solutions for floating-point math, charting, GUIs, and hardware integration. You'll need to complete a few actions and gain 15 reputation points before being able to upvote. Let’s create a simple shell script let_cmd. Jan 10, 2024 · Arithmetic expansion is an important feature in Bash. This feature simplifies tasks like addition, subtraction, I have this Bash script and I had a problem in line 16. In this new Advanced Math Calculation on Linux post, we cover how to use the GNU bc command line tool and how to write your own mathematical functions Arithmetic expansion allows the evaluation of an arithmetic expression and the substitution of the result. In this tutorial, you will learn Bash Arithmetic Operators with the help of examples. Learn how to perform division in Bash using arithmetic expansion, expr, and bc for floating-point division. Evaluation is done in the largest fixed-width integers available, with no check Shell Parameter Expansion (Bash Reference Manual)If the first character of parameter is an exclamation point (!), and parameter is not a nameref, it introduces a level of indirection. In this comprehensive guide, you‘ll learn how to fully utilize your Linux shell as an integrated calculator and data processing engine. How expr Works The basic syntax of […] Apr 2, 2024 · Bash comparison operators help programmers to compare string and number and take necessary result from the comparison result. It can be extremely useful for performing math, comparisons, finding lengths and indexes, regex matching, and more. Shell variables are allowed as operands; parameter expansion is performed before the expression is evaluated. This guide will demonstrate the main techniques for arithmetic in Bash with examples. Since there is no command named 50, you receive the error: Bashispainful. This variable retains its properties when assigned to, and the value returned after the assignment is the number of seconds since the assignment plus the assigned value. Feb 28, 2024 · Bash Arithmetic Operations Performing basic arithmetic operations such as addition, subtraction, multiplication, and division is essential for many scripting tasks. Discover how to bash evaluate expression with ease. Prerequisites Command line/terminal Mar 31, 2023 · Bash math operations or Bash arithmetic refers to mathematical operations that can be performed within a Bash script. Discover the art of arithmetic operations in bash. Several automation tasks require basic arithmetic operations, such as converting CPU temperature to Fahrenheit. Bash Arithmetic Operators - Learn all arithmetic operators supported by Bash Shell with description and examples provided for each operator. Bash Addition In Bash scripting, you can perform arithmetic addition using arithmetic expansion, the expr command, and the let command. Bash shell supports a lot of arithmetic operators. sh: line 2: 50: command not found The solution is remove the space so that the Var1 is assigned to a non empty Feb 1, 2018 · That's because, as I mentioned, bash cannot do floating point maths, and so 0. This article talks about ins and out of arithmetic expansion in Bash. Solve Bash blind spots by embedding other scripting languages into your Bash scripts to get the features you need. The backslash tells Bash/Zsh that you want to escape that behaviour and treat the asterisk as a multiplication symbol. Dec 19, 2022 · man bash, ARITHMETIC EVALUATION describes it as such: Shell variables are allowed as operands; parameter expansion is performed before the expression is evaluated. In this article, we will explore different techniques to perform floating-point math calculations in Bash, along with practical examples. Our mission is to create an elementary and middle school math Jul 30, 2024 · Learn how to use the if statement in Bash to compare multiple values and expressions. The syntax of Bash and the KornShell is very similar, so I thought the below comparison of Bash arithmetic vs. How can I take the previous result of line 15 and add it to the variable in line 16? Apr 17, 2018 · How to use the expr, factor, jot, and bc commands to do math calculations on Linux systems. The bash shell has built-in arithmetic option. Learn how to use the modulo operator in Bash scripting. Feb 29, 2024 · Arithmetic expressions enable substitution of numeric variables and calculations into strings for printing and command execution and can greatly simplify math-heavy workflows and scripting. Bash contains features that appear in other popular shells, and some features that only appear in Bash. Check that this works in sh. It shows a few techniques to calculate certain expression in Bash. Apr 26, 2025 · Bash, a widely-used Unix shell, is not natively equipped to handle floating-point math. What's reputation and how do I get it? Instead, you can save this post to reference later. Discover quick techniques for calculations and unleash your scripting potential effortlessly. This syntax allows you to perform a variety of mathematical operations, such as addition, subtraction, multiplication, and division. Shell Arithmetic (Bash Reference Manual)6. Bash, an acronym for Bourne-Again SHell, is a widely-used Unix shell that enables users to execute commands and scripts across various systems. This guide unveils simple methods to perform calculations smoothly in your scripts. Bash Conditional Expressions (Bash Reference Manual)6. Math in Bash Bash supports a number of basic and more advanced arithmetic operations. Learn essential Linux bash shell math techniques for efficient scripting, covering arithmetic expressions, command tools, and basic mathematical operations for system administrators and developers. Arithmetic Operations available with Let Command Sync to video time Description Bash Shell Scripting Tutorial 15 - Arithmetic Operators | Bash math for beginners 0Likes 0Views 9mAgo Dec 13, 2017 · Learning Tree Instructor John McDermott outlines how to simplify integer math when writing bash shell script. Constants with a leading 0 are interpreted as octal numbers. For example, you can use && and || instead of -a and -o and there's a regular expression matching operator =~. Jan 16, 2024 · Learn how to use various commands and utilities for arithmetic calculations in Bash, such as declare, expr, bc, dc, awk, and more. Discover how to bash add numbers effortlessly. Aug 18, 2025 · Learn to perform arithmetic operations like addition, subtraction, multiplication and division in bash scripts. Syntax: ((expression)) ((var1+var2)) ((var1-var2)) ((var1*var2)) ((var1/var2)) Bash Arithmetic Operations Example: For example, take an input of two numeric values and What is Math Bash? Math Bash is a math competition written and hosted by Dulles High School Mu Alpha Theta (National Math Honor Society). ), and arithmetic expansion, in bash Of the 346k visitors to this question thus far, I'd be willing to bet 344. 3 tells it to round the number to 3 decimal places. Mar 22, 2025 · Would you like a quick, distraction-free way to solve your math problems the way scientists and engineers do? Many tools let you do math right in the Linux terminal. Learn how to use the let command in this tutorial. 249 bash As noted by others, bash does not support floating point arithmetic, although you could fake it with some fixed decimal trickery, e. byqby wwg zrire wdz bwnzk osiuc avmdlqc bjnjr qoc kfhauq insf vrk xrgdt xxtj oewi