C-扫描字符串并将其分配给结构中的char *吗？

Question

I was requested to program a sort of online market that allows you to buy cameras and accesories. I have a struct "User" which i will list bellow. I want to be able to create a user through commandprompt, so in main there is a menu that requests you data (name, locality, country, etc) to registrer the user. Everything seems quite alright until i try to assign the char* name variable within the struct a value through scanner. (I previuosly initialized the struct, (name == NULL))

    switch (option) {
        case 1:
            printf("New User Registration:\n");
            user = newUser();
            while (user->name == NULL) {
                printf("Insert users name:\n");
                scanf("%s",user->name);
                printf("%s",user->name);
            }

Also heres the function newUser(). Please be very detailed in your answers, im very new to C and its quite dificult for me.

User* newUser(){
User* user = (User*)malloc(sizeof(User));
if(user != NULL){
    user->name= NULL;
    user->country= NULL;
    user->direction=NULL;
    user->id=NULL;
    user->locality=NULL;
    user->phoneNumber=NULL;
    user->postalCode=NULL;
    user->province=NULL;
    user->role = client;
}
return user;

}

Answer 1

You probably want the m option. Change your scanf call to

scanf("%ms", &user->name);

scanf man page

An optional 'm' character. This is used with string conversions (%s, %c,%[), and relieves the caller of the need to allocate a corresponding buffer to hold the input: instead, scanf() allocates a buffer of sufficient size, and assigns the address of this buffer to the corresponding pointerargument, which should be a pointer to a char * variable (this variable does not need to be initialized before the call). The caller should subsequentlyfree(3) this buffer when it is no longer required.