case command in Linux with examples

The case command in Linux is an essential tool for simplifying script logic, especially when multiple if/elif conditions need to be evaluated for a single variable. It offers a more readable and efficient way to execute commands based on pattern matching, making your shell scripts easier to maintain and understand.

Here, we will better understand the case command in Linux, learning about its syntax, examples, and options.

Syntax

case WORD in [PATTERN [| PATTERN]...) COMMANDS ;;]... esac

where,

• WORD: The variable or value that you want to match against different patterns.
• PATTERN: One or more patterns to compare against the WORD. Each pattern is followed by commands to execute if the pattern matches.
• COMMANDS: The commands to run when a specific pattern matches the WORD.
• ;;: Ends the command block for each pattern.
• esac: This marks the end of the case statement (it’s case spelled backward)

Basic Example

Common Option for the case Command

help case: Displays help information and details about the case command usage.👁 help case

Conclusion

The case command is an adaptable and efficient alternative to if/elif when dealing with multiple conditional checks on a single variable. By using pattern matching, case allows for more readable and maintainable scripts, particularly when handling a wide variety of input conditions.