\fBtermkey_push_bytes\fP() allows more bytes of input to be supplied directly into the input buffer of the termkey instance. If there was no buffer space remaining then -1 is returned with \fIerrno\fP set to \fBENOMEM\fP.
This function, along with \fBtermkey_getkey\fP(3), makes it possible to use the termkey instance with a source of bytes other than from reading a filehandle.
For synchronous usage, \fBtermkey_waitkey\fP(3) performs the input blocking task. For use against a regular stream filehandle that supports \fBread\fP(2), see \fBtermkey_advisereadable\fP(3).
\fBtermkey_push_bytes\fP() the number of bytes consumed from the input (which may be smaller than the length provided, if the buffer runs out of space) or -1 cast to \fBsize_t\fP if an error occurs, in which case \fIerrno\fP is set accordingly.
