main() 函數中簡單程序的分段錯誤

Question

我剛開始自學 C，並想在 main() 中編寫一個基本程序，該程序將接受用戶輸入的密碼，使用正確的密碼進行檢查，並獲得適當的輸出。 然而，程序開始運行並讀取用戶輸入，但隨后突然在錯誤 Segmentation Fault (code dumped) 下終止。 導致錯誤的代碼有什么問題？

#include <stdio.h>

int main(void)
{
    printf("Enter the password\n");
    char guess;
    scanf(" %c", &guess);
    char password[] = "Hello123";
    int correct = 0;

    while (correct != 1){
        if(strncmp(password,guess)==0){
            printf("Success! You have logged in with your password 
            %c\n",guess);
            correct +=1; 
        }
        else
        {
            printf("Incorrect password. Try again\n");
        }
    }
}

Answer 1

嘿，我有幸重新編碼您的代碼

#include <stdio.h>
#include <string.h>
int main(void)
{
    char *guess;
    const char password[] = "Hello123";
    int correct = 0;

    while (correct != 1){
        /*
         * Include the input prompt inside while loop
         */
        if (correct == 0){
            printf("Enter the password\n");
            scanf(" %s", guess);
        }

        if(strncmp(password,guess, 10)==0){ //strncmp accept 3 params, set length e.g 10
            printf("Success! You have logged in with your password %s\n",guess);
            correct = 1;
        }
        else
        {
            printf("Incorrect password. Try again\n");
            correct = 0;
        }
    }
}