Search results
Apr 18, 2023 · There are many useful bash scripts that can make things easier. Many things can be done just using the terminal. Here is a list of some of such useful bash scripts through which we can do things that cannot be done manually. 1. Counting the number of files(or directory) in a given directory: Go to the directory in which you want to count the number
Jan 16, 2024 · 1. How to Create a Simple Calculator in Bash. Creating a simple calculator involves taking user input and selecting the proper arithmetic operators. Here is the Bash script of a basic calculator: #!/bin/bash # Take user input read -p "Enter the first number: " a read -p "Enter the second number: " b # Input type of operation echo "Enter Choice ...
- (1)
- The main downside of the SECONDS variable in calculating elapsed time is precision. SECONDS variables always provide the execution time of a script...
- To calculate the total of a few numbers in Bash, use the for loop. Let’s say you have some numbers in an array. Use the following code to calculate...
- To calculate the certain percentage of a number in Bash, multiply the number with the required percentage then divide the result by 100. Think of a...
- To calculate the average of some numbers in Bash, first sum up numbers then divide the summation with the count of numbers. Look at the script to i...
Nov 5, 2024 · This calculator script is a beginner-friendly way to explore Bash scripting. It includes basic arithmetic operations, input validation, and a user-friendly interface with prompts and messages.
- Introduction to Integers and Floating-Points
- What Are The Bash Arithmetic Operators?
- Doing Math in Bash with Integer
- Doing Floating-Point Arithmetic in Bash
- Detailed Examples & FAQ
Before we get into the details on how to do Math in Bash, remember that an integer is a whole numberthat is not a fraction or decimal and is anywhere from zero to positive or negative infinity. For example, 42, 36, and -12 are integers, while 3.14 and √2 are not. The set of integers includes all negative integers (whole numbers that has value less ...
The Bash shell has a large list of supported arithmetic operators to do math calculations. They work with the let, declare, and arithmetic expansionmethods described further below in this post.
Natively, Bash can only do integer arithmetic, if you need to do arithmetic operations that requires floating-point arithmetic, see the next section.
Using the printf builtin command
A noteworthy but unconventional way to do floating-point arithmetic in native bash is to combine Arithmetic Expansion with printf using the scientific notation. Since you can’t 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. For example, the operation 2/3 in Artithmetic Expansion as $((2/3)) would return 0. To get the floating number using printf you would use a for...
Using the awk command line
Another way to do floating-point arithmetic is to use GNU awk. You can use all the arithmetic operators listed in the table earlier in this post and the printffunction to adjust the precision of the printed results. When using negative values, make sure to leave white space between signs.
Using the bc command line
Since you can’t do floating-point arithmetic natively in Bash, you will have to use a command-line tool. The most common one is “bc - An arbitrary precision calculator language”. To start the interactive mode, you simply need to type bc in your command prompt. You can use the -q (quiet) option to remove the initial bcbanner. Of course, you can also use bc in a non-interactive mode by using the STDIN to send your formula to bc then get the output on STDOUT, or by using thehere-docnotation. The...
How to calculate a percentage in Bash?
You can calculate a floating-point precision percentage in Bash using the printf method and Arithmetic Expansion, or you can calculate a rounded integer percentage using Arithmetic Expansion with the ((...))notation. The round-up approach leverages the shell behavior to round toward zero (0). We first calculate twice the percentage then subtract the regular percentage from it. This gives us the formula: roundup = (int) (2 * x) - (int) x where xis the percentage calculation.
How to find a factorial in a shell script?
To calculate the factorial of a number in Bash or any POSIX shell, you can use the Arithmetic Expansion and a recursive function. The factorial function symbol in mathematic is ! and a factorial is defined by the formula n! = (n-1)! * n.
How to create a simple bash calculator function?
As a thought experiment, you can create a calculator command to do math by using abash function, a bash arithmetic expression, and a bash variable inference. Every time the calculator function is called, it will update a variable name by a given value or by default 1 with a given arithmetic operator. Example: counter . You can also implement an interactive version of asimple calculator by using bc. Obviously, this example is just to demonstrate some of the concept...
- Nicolas Brousse
Sep 15, 2019 · We can solve it using the Bottom-Up approach of dynamic programming. Time Complexity: O(n) Space Complexity: O(n) The space complexity can be reduced to O(1) by using variables to store the previous three values instead of using an array.
Jun 24, 2019 · We will build a bash example project, calculator program and at the same time reinforce all the concepts already taught. In a quick summary, we’ve explored the fundamental topics on variables, decisions, control statements, and arguments. There were minor subtopics including using comments in bash programs and operator types.
People also ask
How do I create a simple calculator using Bash?
How to create a calculator command to do math?
How to perform basic arithmetic operations in Bash?
How to calculate the total of a few numbers in Bash?
How to calculate the factorial of a number in Bash?
How to calculate percentage in Bash?
Jul 1, 2015 · I am learning Bash Shell Scripting as a section from the Linux Foundation LFS101x.2 and there is a Lab to create a simple Bash calculator. The Lab details are found here: Lab 5 I'm trying to run the script by:
