Assignment 4 - Problem 3

problem3.c

#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <stdio.h>

struct auth {
    char name[32];
    int auth;
};

struct auth *authO;
char *service;
struct auth *authPtr;

int main(int argc, char **argv) {
    char line[128];
    int pos = 0;
    
    while(1) {
        printf("[ auth = %p, service = %p , authPtr = %p ]\n", authO, service, authPtr);
        
        if(fgets(line, sizeof(line), stdin) == NULL) {
            break;
        }
        
        if(strncmp(line, "auth ", 5) == 0) {
            authO = malloc(sizeof(struct auth));
            memset(authO, 0, sizeof(struct auth));
            if(strlen(line + 5) < 31) {
                strcpy(authO->name, line + 5);
            }
        }
        if(strncmp(line, "reset", 5) == 0) {
            free(authO);
        }
        if(strncmp(line, "alias", 5) == 0) {
            authPtr = authO;
        }
        if(strncmp(line, "service", 6) == 0) {
            if(service == NULL) {
                service = malloc(sizeof(line));
                memset(service, 0, sizeof(line));
            }
            if(strlen(line + 6) < 15) {
                strcat(service, line + 6);
                pos += strlen(line + 6);
            }
        }
        if(strncmp(line, "login", 5) == 0) {
            if(authPtr->auth) {
                printf("you have logged in already!\n");
            } else {
                printf("please enter your password\n");
            }
        }
  }
}

This is based on a Youtube video by liveoverflow channel