Case example in shell script(SWTICH)

The below code snippet shows how can we use case statement in shell script. case is acting here like switch statement in programming languages.

-bash-3.2$ cat case_example
#!/bin/bash
# Testing ranges of characters.
echo; echo "Hit a key, then hit return."
read Keypress
case "$Keypress" in
  [[:lower:]]   ) echo "Lowercase letter";;
  [[:upper:]]   ) echo "Uppercase letter";;
  [0-9]         ) echo "Digit";;
  *             ) echo "Punctuation, whitespace, or other";;
esac      #  Allows ranges of characters in [square brackets],
exit 0
-bash-3.2$

OUTPUT:

-bash-3.2$ sh case_example
Hit a key, then hit return.
a
Lowercase letter
-bash-3.2$ sh case_example
Hit a key, then hit return.
B
Uppercase letter
-bash-3.2$ sh case_example
Hit a key, then hit return.
4
Digit
-bash-3.2$ sh case_example
Hit a key, then hit return.
!
Punctuation, whitespace, or other
Explanation :

read Keypress            --> used to get input from keyboard
[[:lower:]]                   --> it accept all lower case characters
[[:upper:]]                   --> it accept all upper case characters
[0-9]                          --> it accepts all digits