AVR Libc Library Reference
fdev_set_udata(stream, u)
fdev_get_udata(stream)
fdev_setup_stream(stream, put, get, rwflag)
FDEV_SETUP_STREAM(put, get, rwflag)
fdev_close()
putc(__c, __stream)
putchar(__c)
getc(__stream)
getchar(void)
