what is the type of user->profile_pic
int print_user(const User *user) {
    if (user == NULL){
        return 1;
    }

    int i = 0;
    Post *curr = user->first_post;
    char *time_string;

    FILE *profile_pic;
    char row[45];

    // print profile pic
    printf("%d\n", (strcmp(NULL, user->profile_pic) == 0));
    if (user->profile_pic == NULL){
        profile_pic = fopen(user->profile_pic, "r");
        while (fscanf(profile_pic, "%s", row) != EOF){
            printf("%s\n", row);
        }
    }

    // print name
    printf("Name: %s\n", user->name);
    // dashes
    printf("------------------------------------------\n");
    // print friends
    printf("Friends:\n");
    while (user->friends[i] != NULL){
        printf("%s\n", user->friends[i]->name);
        i++;
    }
    //print posts
    printf("------------------------------------------\n");
    printf("Posts:\n");
    while (curr != NULL){
        time_string = ctime(curr->date);
        printf("From: %s\n", curr->author);
        printf("Date: %s\n", time_string);
        printf("%s\n", curr->contents);
        curr = curr->next;
        if (curr != NULL){
            printf("\n===\n");
        }
    }
    printf("------------------------------------------\n");
    return 0;
}