Guide: Using Case Statements in Bash Scripts – Guide
Bash case statements are like if-else explanations, but they are more direct and less complex. They help to match a variable with some qualities. It’s used when you require IF-else statements with multiple joints… It’s a lot like the switch proclamation in C, however, the slam case statement doesn’t advance once the example is coordinated ..
case statements
Case statements are used to group options into a single, specific situation. When you have multiple options in the form of a pattern match, case statements can help organize them. If you find yourself writing a long if … else … else … else if multilevel ladder, you can replace it with a case statement. Your code will be easier to read and maintain.
Structure
If the value of $variable matches any of the patterns in the statement, then that command will be executed. ..
If the first successful match for a pattern finds commands up to the double semicolon ‘;;’, then the script execution will continue immediately after the esac statement. ..
If the variable $ is not matched by any of the patterns you specified, you can provide an optional catch-all pattern just before the final else clause. This is done using the pattern ‘*)’ and is equivalent to the else clause in an if…elif…else statement. ..
When writing bash scripts, it is important to remember to use the mandatory double semicolon at the end of each set of commands. This serves two purposes: first, it instructs bash to ignore the rest of the case structure and jump to the final command in that set; and second, it prevents any potential errors from occurring when multiple commands in a set are executed simultaneously. ..
Final note
Guide: Using Case Statements in Bash Scripts In this guide, we will be looking at how to use case statements in Bash scripts. We will start by looking at the basics of case statements and then move on to more complex examples. The Basics of Case Statements A case statement is a type of statement that can be used to control the behavior of a Bash script. A case statement can have one or more clauses, which are separated by commas. The clauses can contain different values, and the value of a clause can be changed based on the value of another clause. For example, the following code example uses a case statement to determine whether the user is logged in or not: if [ -z “$USER” ]; then echo “User not logged in” fi This code example uses a simple if statement to determine whether or not the user is logged in. If the user is not logged in, then they are shown an error message. If they are logged in, then the code continues without any other clauses. This type of condition can be used for anything from checking for specific files to determining when a certain event happens (like waking up from sleep).
case commands $ variable inpattern-1 ;; pattern-2) commands ;; pattern-3 | pattern-4 | pattern-5) commands ;; pattern-N) commands ;; esac
