\fBtermkey_advisereadable\fP() informs the instance that new input may be available on the underlying file descriptor and so it should call \fBread\fP(2) to obtain it. If at least one more byte was read it will return \fBTERMKEY_RES_AGAIN\fP to indicate it may be useful to call \fBtermkey_getkey\fP(3) again. If no more input was read then \fBTERMKEY_RES_NONE\fP is returned.