//str[20] = '\0'; 이 부분을 입력하지 않으면 이상한 문자열이 출력되는데 fread함수는 마지막에 \0을 받아오지 않나요?

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#include <stdio.h>
#include <stdlib.h>

int main()
{
    char *str;
    FILE *fp = fopen("a.txt", "r");
    str = (char *)malloc(21);


    fread(str, sizeof(char), 20, fp);
    **//str[20] = '\0';**
    printf("%s", str);

    fclose(fp);
    system("PAUSE");
    return 0;
}