In this statement, we are comparing one to one. For example, the following age.sh bash script takes your age as an argument and will output a meaningful message that … We also looked at how to implement if statements at the Bash command line. If statement and else statement could be nested in bash. I also find that just typing any complex if then else command, hit enter, and then after it executes just hit the up arrow. If the first condition is true then “Statement 1” will execute an interpreter will directly go to the normal program and execute the further program. Bash if Statement. In this section of our Bash Scripting Tutorial you will learn the ways you may use if statements in your Bash scripts to help automate tasks. If elseis followed by an ALTERNATE-CONSEQUENT-COMMANDSlist, and the final command in the final ifor elifclause has a non-zero exit status, then … In the first if-else expression, condition is true and hence the statements in the if block are executed. 1 if..then..else Syntax. This can be further enhanced to use if..elif..else and nested if so we will cover all such possible scenarios in this tutorial guide. Bash if elif Statement. For example, find out if file exists (true condition) or not (false condition) and take action based on a condition result. Set of commands to be run when the is false. LinuxConfig is looking for a technical writer(s) geared towards GNU/Linux and FLOSS technologies. In this example, we shall look into two scenarios where in first if-else statement, expression evaluates to true and in the second if-else statement, expression evaluates to false. Nested if statement 5. case statement Each type of statements is explained in this tutorial with an example. Finally, the fi closes the statement. 51 1 1 bronze badge. If value equals 1. This tutorial describes how to compare strings in Bash. If-else statements in bash scripting is similar to any other programming languages; it is a method for a program to make decisions. In bash, you can use if statements to make decisions in your code. You can use bash if else in any section of your shell script such as for loops, while loops, functions etc. Single if statements are useful where we have a single program for execution. Let’s change this slightly: Here we introduced an else clause; what commands to execute when the condition in the if statement has proven to be false (or not true). If you are just starting to explore the Bash coding language, you will soon find yourself wanting to create conditional statements. In the case of the first 'if statement', if a condition goes false, then the second 'if condition' is checked. Bash If Else : If else statement is used for conditional branching of program (script) execution in sequential programming. If the first test command evaluates to true, it executes the first action you want to happen. Check the below script and execute it on the shell with different-2 inputs. For example: Here we simply created a small myscript.sh shell script by using echo and the > redirector to redirect the output from our echo to a file. In this Bash Tutorial, we have learnt about the syntax and usage of bash if else statement with example bash scripts. If statements (and, closely related, case statements) allow us to make decisions in our Bash scripts. Following is an example for the same. Note: There can only be one ELSE clause in an IF statement. You saw in the above example, no action is performed or any statement displayed when the condition was false. 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