login_alloc_entry
struct logininfo *login_alloc_entry(pid_t pid, const char *username,
li1 = login_alloc_entry((int)getpid(), username, NULL, ttyname(0));
li = login_alloc_entry(pid, user, host, tty);
li = login_alloc_entry(pid, user, host, ttyname);
li = login_alloc_entry(pid, user, NULL, tty);