Bash Floating Point Math With Variables

03 Feb, 2021

However what if we use floating point in Bash shell. Since you cant do floating-point in bash you would just apply a given multiplier by a power of 10 to your math operation inside an Arithmetic Expansion then use printf to display the float.

Math Arithmetic How To Do Calculation In Bash

This is where the problem is encountered and we cannot write a math function of our own.

Bash floating point math with variables. The following commands show how to perform floating point arithmetic addition subtraction multiplication and division using the Ruby programming language at the bash prompt. With intermediate variables. Fortunately bc gallops to the rescue.

If you need to perform calculations on floating point numbers you will need to call out to a utility program like bcor Python. Bash supports redirections so we can feed the floating point computations and the math functions into some other programs input who understands it. If you for example want two decimals use 2f instead of f.

This may come as a surprise but Bash only supports integer arithmetic natively. Float_eval 120 30 if float_cond 100 90. Binbash if 2.

As a quick proof to yourself try multiplying integers then do the same with floating point numbers. Bash cant handle floating point calculations and it lacks operators for certain important mathematical functions. Note the use of the backtick myvarcommand syntax to assign the results of the arithmetic to a bash variable.

Usage is quite simple. There must be a way to do this and yes. Not just a versatile arbitrary precision calculation utility bc offers many of the facilities of a programming language.

Then echo 2 Expected two arguments exit 1 fi x1 y2 sum bc. The short and direct answer is using bc command An arbitrary precision calculator language Just run bc and enter some floating point calculation expression such as 1282 bc will give the result. A noteworthy but unconventional way to do floating-point arithmetic in native bash is to combine Arithmetic Expansion with printf using the scientific notation.

Timestep0125 i2 t echo timestep i awk printf 43fn12. Or you can use bc calculations see man bc for details. Bash does not support floating point operations.

Modify the printf formatting string to suit your needs. Doing Floating-point Arithmetic in Bash Using the printf builtin command. RemainingTime durationnumOfRevisionsremainingRevision echo remainingTime 60 minutes and remainingTime 60 seconds remaining All variables are integer numbers duration is the number of seconds My problem is to calculate the variable remaining time so as to use print formatted in the second line.

Binbash Floating point number functions. To do floating point calculations in a shell script you can invoke awk eg. Integers are natively supported in Bash shell.

Then echo As expected 100 is greater than 90 fi a120 b30 c float_eval a b The code for the functions follows.

Performing Math Calculation In Bash How To Do Math Math Evaluating Expressions

5 Useful Ways To Do Arithmetic In Linux Terminal Linux Blimp

Shell Scripting Tutorial For Beginners 11 Floating Point Math Operations In Bash Bc Command Youtube

Iterate And Check If A Bash Array Contains A Value Learn How To Use Bash Array Variables And Associative Bas Regular Expression Being Used Quotes Single Words

Math Arithmetic How To Do Calculation In Bash

What Is The Bash Null Command Learn About The Bash Null Command Also Known As The Posix Shell Colon Command This Post Cover Concrete Command Use Case Linux

Math Arithmetic How To Do Calculation In Bash

5 Useful Ways To Do Arithmetic In Linux Terminal Linux Blimp

How To Format Date And Time In Linux Macos And Bash Find Out How To Manipulate Date And Time On Linux And Macos Systems As Well As Nativ Linux Dating Format