Thread: help with loop

Hi, im having trouble with this program:

Code:

#include <stdio.h>
#include <string.h>

char set_user[20];
char set_pass[20];
char user[20];
char pass[20];
char old_pass[20];
char new_pass[20];
char old_user[20];
char new_user[20];
char menu_choice[20];
int a = 3;
int b = 3;
int strcmp( const char *str1, const char *str2 );
char option_choice[20];
void print_options() {
	printf("________________________________________\n");
	printf("TYPE 'user' TO CHANGE YOUR USERNAME\n");
	printf("TYPE 'pass' TO CHANGE YOUR PASSWORD\n");
	printf("TYPE 'logout' TO LOGOUT\n");
	printf("TYPE 'options' TO PRINT OPTIONS\n");
	printf("________________________________________\n");
}
void change_pass(char *str1, char *str2, char *str3) {
	printf("Old Password: ");
	scanf("%s", str1);
	printf("New Password: ");
	scanf("%s", str2);
	if (strcmp (str1, str3) == 0 ) {
		str3 = str2;
		printf("YOUR PASSWORD HAS NOW CHANGED\n");
	}
	else {
		printf("INCORRECT OLD PASSWORD\n");
	}
}
void change_user(char *str1, char *str2, char *str3) {
	printf("Old Username: ");
	scanf("%s", str1);
	printf("New Username: ");
	scanf("%s", str2);
	if (strcmp (str1, str3) == 0 ) {
		str3 = str2;
		printf("YOUR USERNAME HAS NOW CHANGED FROM %s TO %s\n", str1, str2);
	}
	else {
		printf("INCORRECT OLD USERNAME\n");
	}
}
void print_first_options() {
	printf("WELCOME\n");
	printf("_______________________________\n");
	printf("TYPE 'register' TO REGISTER\n");
	printf("TYPE 'login' TO LOGIN\n");
	printf("TYPE 'users' TO SHOW USERS\n");
	printf("TYPE 'options' TO PRINT OPTIONS\n");
	printf("_______________________________\n");
}	

main() {
	while(strcmp (a, b) == 0 ) {
		
		print_first_options();
		printf("Menu choice: ");
		scanf("%s", menu_choice);
		if (strcmp (menu_choice, "register") == 0 ) {
			printf("REGISTER\n");
			printf("SET YOUR USERNAME\n");
			printf("Username: ");
			scanf("%s", set_user);
			printf("SET YOUR PASSWORD\n");
			printf("Password: ");
			scanf("%s", set_pass);
			printf("Your now Registered\n");
		}
		else if (strcmp (menu_choice, "login") == 0 ) {
			printf("Username: ");
			scanf("%s", user);
			printf("Password: ");
			scanf("%s", pass);
			if (strcmp (user, set_user) != 0 || strcmp (pass, set_pass) != 0 ) {
				printf("USERNAME OR PASSWORD IS INCORRECT\n");
				printf("YOU MAY NEED TO REGISTER\n");
			}
			else {
				printf("WELCOME TO YOUR SYSTEM %s\n", user);
				print_options();
				printf("Option choice: ");
				scanf("%s", option_choice);
				if (strcmp (option_choice, "options") == 0 ) {
					print_options();
				}
				else if (strcmp (option_choice, "user") == 0 ) {
					printf("CURRENT USERNAME: %s\n", user);
					change_user(old_user, new_user, user);
				}
			}
		}
	}
}

when i compile and run:

Code:

/root/Program Files/welcome_to_your_system.c: In function 'main':
/root/Program Files/welcome_to_your_system.c:62: warning: passing argument 1 of 'strcmp' makes pointer from integer without a cast
/root/Program Files/welcome_to_your_system.c:62: warning: passing argument 2 of 'strcmp' makes pointer from integer without a cast

can someone please tell me what im doing wrong

Thanks.

strcmp only compares strings. Did you look at line 62? Did you see what you put in there? Actually, I'm not sure why you put that there, since a and b never change....

(Also: For the love of all that is good, get that prototype for strcmp out of there. You're including the right header file, let it do its job.)

Code:

	if (strcmp (str1, str3) == 0 ) {
		str3 = str2;

I'm sorry to say you cannot assign strings like that. You will need to use strcpy()

What you get doing it that way is both pointers pointing to the same address, but the contents of the strings themselves are not copied.