即使我输入正确，用户名和密码也不匹配

Question

我正在尝试创建一个程序以使用用户名和密码进入系统。但是在创建帐户后，当我输入我的用户名和密码（从 SignUP 功能存储）登录时，它显示不正确。我在哪里犯了错误，我该如何解决？我已经给出了与这个问题相关的具体代码。 TIA

struct information
{
char username[20];
char password[20];
int date, month, year;
char pnumber[20];
int age[20];
char fname[20];
char lname[20];
char fathname[20];
char mothname[20];
char address[50];

};  

void signup()
{
char username[20];
char password[20];
int passwordlength, i, seek = 0;
char ch;
FILE *fp, *fu;
struct information u1;
struct information p1;


// Opening file to
// write data of a user
fp = fopen("username.txt", "ab");

system("cls");
printf("\n\n!!!!!CREATE YOUR ACCOUNT!!!!!");

printf("\n\nFIRST NAME...");
scanf("%19s", u1.fname);

printf("\nLAST NAME...");
scanf("%19s", u1.lname);

printf("\nFATHER's NAME...");
scanf("%19s", u1.fathname);

printf("\nMOTHER's NAME...");
scanf("%19s", u1.mothname);

printf("\nADDRESS..");
scanf("%19s", u1.address);

printf("\nDATE OF BIRTH...");
printf("\nDATE-");
scanf("%d", &u1.date);
printf("\nMONTH-");
scanf("%d", &u1.month);
printf("\nYEAR-");
scanf("%d", &u1.year);

printf("\nPHONE NUMBER...");
scanf("%19s", u1.pnumber);

printf("\nAGE...");
scanf("%d", &u1.age);

printf("\nUSERNAME.. ");
scanf("%19s", u1.username);

printf("\nPASSWORD..");
scanf("%19s", p1.password);


fwrite(&u1, sizeof(u1), 1, fp);

fclose(fp);
printf("\n\nACCOUNT CREATED SUCCESSFULLY.\n");

char option[10];
printf("\nPRESS ANY KEY THEN ENTER TO GO TO SIGN IN PAGE");
scanf("%s", option);
signin();
}

void signin()
{
system("cls");

char username[20];
char password[20];

int i, j, k;
char ch;
FILE *fp, *fu;
struct information u1;
struct information p1;


// Opening file of
// user data
fp = fopen("username.txt","rb");

if (fp == NULL)
{
    printf("\nERROR IN OPENING FILE\n");
    printf("FILE DOESN'T EXIST\nYOU HAVE TO CREATE AN ACCOUNT FIRST\n");
    printf("PRESS ANY KEY & ENTER TO CREATE AN ACCOUNT\n");
    char option[10];
    scanf("%s", option);
    signup();
}
gotoxy(35, 10);
printf("==== LOG IN ====");

// Take input
gotoxy(35, 12);
printf("ENTER USERNAME.. ");
scanf("%19s", username);

gotoxy(35, 14);
printf("ENTER PASSWORD.. ");
scanf("%19s", password);


// Checking if username & password
// exists in the file or not
while (fread(&u1, sizeof(u1), 1, fp))
{
    if (strcmp(username, u1.username) == 0)
        if (strcmp(password, u1.password) == 0)
        {
            mainmenu();
        }

fclose(fp);
}

Answer 1

在signup() 函数中，您将密码读入p1.password 字段，但随后仅将u1 结构写入文件。只需将scanf("%19s", p1.password); 更改为scanf("%19s", u1.password);。