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HTOND(3)			    BRL-CAD			      HTOND(3)

NAME
       htond, ntohd - convert double-precision floating	point numbers between
       host and	network	format and byte	order

SYNOPSIS
       htond(netptr, hostptr, count);

	     unsigned char *netptr;
	     unsigned char *hostptr;
	     int count;

       ntohd(hostptr, netptr, count);

	     unsigned char *hostptr;
	     unsigned char *netptr;
	     int count;

DESCRIPTION
       These routines are used for conversion between the local	host 64-bit
       ("double	precision") representation, and	64-bit IEEE double precision
       representation, in "network order", i.e., big-endian, the MSB in	byte
       [0], on the left.

       As a quick review, the IEEE double precision format is as follows: sign
       bit, 11 bits of exponent	(bias 1023), and 52 bits of mantissa, with a
       hidden leading one (0.1 binary).	When the exponent is 0,	IEEE defines a
       "denormalized number", which is not supported here. When	the exponent
       is 2047 (all bits set), and: all	mantissa bits are zero,	value is
       infinity*sign, mantissa is non-zero, and: msb of	mantissa=0: signaling
       NAN msb of mantissa=1: quiet NAN

       Note that neither the input or output buffers need be word aligned, for
       greatest	flexibility in converting data,	even though this may impose a
       speed penalty on	some architectures.

       These subroutines operate on a sequential block of numbers, to save on
       subroutine linkage execution costs, and to allow	some hope for
       vectorization.

       On brain-damaged	machines like the SGI 3-D, where type "double"
       allocates only 4	bytes of space,	these routines *still* return 8	bytes
       in the IEEE buffer.

SEE ALSO
       htons(3N), ntohs(3N), htonl(3N),	ntohl(3N)

BUGS
       The VAX handles bytes backwards from most everyone else in the world.
       This is not expected to be fixed	in the near future.

AUTHOR
       BRL-CAD Team

COPYRIGHT
       This software is	Copyright (c) 1988-2013	by the United States
       Government as represented by U.S. Army Research Laboratory.

BUG REPORTS
       Reports of bugs or problems should be submitted via electronic mail to
       <devs@brlcad.org>.

BRL-CAD				  07/08/2017			      HTOND(3)

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | BUGS | AUTHOR | COPYRIGHT | BUG REPORTS

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