int libssh2_channel_flush_ex(LIBSSH2_CHANNEL *channel, int streamid);
int libssh2_channel_flush(LIBSSH2_CHANNEL *channel);
int libssh2_channel_flush_stderr(LIBSSH2_CHANNEL *channel);
DESCRIPTIONchannel - Active channel stream to flush.
streamid - Specific substream number to flush. Groups of substreams may
be flushed by passing on of the following Constants.
LIBSSH2_CHANNEL_FLUSH_EXTENDED_DATA: Flush all extended data substreams
LIBSSH2_CHANNEL_FLUSH_ALL: Flush all substreams
Flush the read buffer for a given channel instance. Individual substreams may be flushed by number or using one of the provided macros.
RETURN VALUEReturn 0 on success or negative on failure. It returns LIBSSH2_ERROR_EAGAIN when it would otherwise block. While LIBSSH2_ERROR_EAGAIN is a negative number, it isn't really a failure per se.