-void clean_environment(const char * const *_white,
- const char * const *_more_white);
-int extattr_namespace_to_string(int _attrnamespace, char **_string);
-int extattr_string_to_namespace(const char *_string, int *_attrnamespace);
-void login(struct utmp *_ut);
-int login_tty(int _fd);
-int logout(const char *_line);
-void logwtmp(const char *_line, const char *_name, const char *_host);
-void trimdomain(char *_fullhost, int _hostsize);
-int openpty(int *_amaster, int *_aslave, char *_name,
- struct termios *_termp, struct winsize *_winp);
-int forkpty(int *_amaster, char *_name,
- struct termios *_termp, struct winsize *_winp);