C program to print uppercase characters in a string using recursion

Write a C program to print uppercase characters in a string using recursion.

  #include <stdio.h>
  #include <string.h>

  /* print uppercase character in give character using recursion */
  void printUpper(char *str) {
        if (*str != '\0') {
                /* prints uppercase characters alone */
                if (*str >= 'A' && *str <= 'Z') {
                        printf("%c", *str);
                }

                printUpper(str + 1);
        }
        return;
  }

  int main() {
        char str[256];

        /* get the input string from the user */
        printf("Enter your input string:");
        fgets(str, 256, stdin);
        str[strlen(str) - 1] = '\0';

        /* prints uppercase character in the given input */
        printf("Upper case characters in given string:");
        printUpper(str);
        printf("\n");
        return 0;
  }

  Output:

  jp@jp-VirtualBox:~/$ ./a.out
  Enter your input string:HeLlO WoRlD
  Upper case characters in given string:HLOWRD