从标准输入

Question

以下代码逐个字符地从stdin流中读取，直到遇到EOF符号（CTRL-D）。但是，当我执行CTRL-D命令时，它不会将其作为EOF字符进行处理。

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

int main() {

    char current_character, next_character;

    int amount_of_characters = 0, amount_of_words = 0, amount_of_newlines = 0;

    while( (current_character = getchar()) != EOF) {
        amount_of_characters++;

        if(isspace(current_character) || current_character == '\n') {

            next_character = getc(stdin);

            if(isalpha(next_character)) {
                amount_of_words++;
                ungetc(next_character, stdin);
            }

            if(current_character == '\n') {
                amount_of_newlines++;
            }
        }
    }

    printf("----- Summary -----\n");
    printf("Characters: %d\nWords: %d\nNewlines: %d\n", amount_of_characters, amount_of_words, amount_of_newlines);

    return 0;
}