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gensio_write(3) 	    Library Functions Manual		 gensio_write(3)

NAME
     gensio_write - Write data to a gensio

SYNOPSIS
     #include <gensio/gensio.h>

     int gensio_write(struct gensio *io, gensiods *count,
			 const void *buf, gensiods buflen,
			 const char *const *auxdata);

     struct gensio_sg {
	 const void *buf;
	 gensiods buflen;
     };

     int gensio_write_sg(struct gensio *io, gensiods *count,
			 const struct gensio_sg *sg, gensiods sglen,
			 const char *const *auxdata);

DESCRIPTION
     Write  data  to the given gensio.	The data is in buf and the length of the
     data is in buflen.  Note that gensio_write may not write all  of  the  data
     given, depending on the gensio type and the internal buffer space.  It will
     return  the  number of bytes actually written in count which may be NULL if
     you don't care.  (Hint: you should almost always care.)

     If gensio_write is unable to write the full amount of data, you should gen-
     erally buffer the unwritten  data	and  call  gensio_set_write_callback_en-
     able(3) to know when you can write the rest of the data.  Many applications
     always  buffer  the  data and enable the write callback to do the write and
     then disable the write callback when all data is written, for consistency.

     gensio_write will never block, if it cannot write	all  the  data	it  will
     write what it can and return.

     auxdata  is  used	to  pass  in gensio specific auxiliary data, such as the
     stream number for SCTP or whether the data is out of band data for SCTP  or
     TCP.

     gensio_write_sg  is like gensio_write, but it takes a scatter-gather struc-
     ture to allow you to combine multiple chunks of data without copying.  Note
     that if you get a partial write, you must figure out where the write  ended
     in your scatter-gather list and start the next write from there.

RETURN VALUES
     Zero is returned on success, or a gensio error on failure.

SEE ALSO
     gensio_err(3), gensio(5)

				   24 Feb 2019			 gensio_write(3)
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