Conditional Statements | Bash
Bash control structures are essential elements for implementing logic and flow control in shell scripts. The if statement is a fundamental structure that allows conditional execution of code based on the success or failure of a test command. It begins with the keyword if, followed by a test condition, and concludes with the fi statement. Nested if statements or the use of elif (else if) can be employed for more complex branching logic.
Looping constructs, such as for, while, and until, enable repetitive execution of code. The for loop iterates over a specified range or list of items, executing the enclosed commands for each iteration. The while and until loops repeatedly execute a block of code as long as a specified condition is true or false, respectively. The loop structure involves a test condition, and the loop continues until that condition is no longer met.
The case statement provides a way to perform multi-way branching based on the value of a variable or expression. It is an alternative to using multiple if statements for such scenarios, offering a cleaner and more readable code structure. The case statement allows developers to compare the value of a variable against different patterns, executing the code associated with the first matching pattern. This construct simplifies complex decision-making processes and enhances the maintainability of Bash scripts.