libssh2_channel_free - free all resources associated with a channel
int libssh2_channel_free(LIBSSH2_CHANNEL *channel);
channel - Channel stream to free.
Release all resources associated with a channel stream. If the channel
has not yet been closed with libssh2_channel_close(3) , it will be
called automatically so that the remote end may know that it can safely
free its own resources.
Return 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