Bash case command is similar to the switch statement of other programming languages. It is useful when you need to check the same variable value in elif statements.
case variable in pattern1) commands1;; pattern2 | pattern3) commands2;; *) commands3;; esac
The value of a variable is matched against patterns if the value matches with any pattern then commands specified under that pattern is executed and all other commands are skipped.
If you want you can write more than one pattern on a single line by separating them with a bar operator.
Commands listed under asterisk symbol are executed only when there is no matching of patterns.
#Bash script to check whether a goven character is vowel or not echo -n "Enter a character: " read -n 1 character case $character in "a" | "e" | "i" | "o" | "u") echo echo "It's a vowel.";; *) echo echo "It's not a vowel.";; esac
Output of the above program
Enter a character: a It's a vowel. Enter a character: q It's not a vowel.
#Bash script to build mini calculator read -p "Enter first number: " firstNumber read -p "Enter second number: " secondNumber echo "What operation you want to perform" echo "1. Addition" echo "2. Subtraction" echo "3. Multiplication" echo "4. Division" read -p "Enter your choice(1-4): " choice case $choice in 1) ans=$(( firstNumber + secondNumber )) echo "Addition of $firstNumber and $secondNumber is $ans";; 2) ans=$(( firstNumber - secondNumber )) echo "Subtraction of $firstNumber and $secondNumber is $ans";; 3) ans=$(( firstNumber * secondNumber )) echo "Multiplication of $firstNumber and $secondNumber is $ans";; 4) ans=$(( firstNumber / secondNumber )) echo "Division of $firstNumber and $secondNumber is $ans";; esac
Output of the above program
Enter first number: 45 Enter second number: 5 What operation you want to perform 1. Addition 2. Subtraction 3. Multiplication 4. Division Enter your choice(1-4): 2 Subtraction of 45 and 5 is 40
