linux如何判断字符串大小写

#!/bin/bash

string1="HelloWorld"
string2="helloworld"

if [[ "$string1" == [Hh]* ]]; then
    echo "string1 is uppercase or mixed case starting with H/h"
else
    echo "string1 is not uppercase or mixed case starting with H/h"
fi

if [[ "$string2" == [hH]* ]]; then
    echo "string2 is uppercase or mixed case starting with H/h"
else
    echo "string2 is not uppercase or mixed case starting with H/h"
fi

#include <stdio.h>
#include <ctype.h>

int main() {
    char str[] = "HelloWorld";
    
    for (int i = 0; str[i] != '\0'; i++) {
        if (isupper(str[i])) {
            printf("Character '%c' is uppercase.\n", str[i]);
        } else if (islower(str[i])) {
            printf("Character '%c' is lowercase.\n", str[i]);
        }
    }
    
    return 0;
}