cde/programs/dtksh/ksh93/src/lib/libast/sfio/sfputd.c

   1 /*
   2  * CDE - Common Desktop Environment
   3  *
   4  * Copyright (c) 1993-2012, The Open Group. All rights reserved.
   5  *
   6  * These libraries and programs are free software; you can
   7  * redistribute them and/or modify them under the terms of the GNU
   8  * Lesser General Public License as published by the Free Software
   9  * Foundation; either version 2 of the License, or (at your option)
  10  * any later version.
  11  *
  12  * These libraries and programs are distributed in the hope that
  13  * they will be useful, but WITHOUT ANY WARRANTY; without even the
  14  * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  15  * PURPOSE. See the GNU Lesser General Public License for more
  16  * details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with these librararies and programs; if not, write
  20  * to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
  21  * Floor, Boston, MA 02110-1301 USA
  22  */
  23 /* $XConsortium: sfputd.c /main/3 1995/11/01 18:33:55 rswiston $ */
  24 /***************************************************************
  25 *                                                              *
  26 *                      AT&T - PROPRIETARY                      *
  27 *                                                              *
  28 *         THIS IS PROPRIETARY SOURCE CODE LICENSED BY          *
  29 *                          AT&T CORP.                          *
  30 *                                                              *
  31 *                Copyright (c) 1995 AT&T Corp.                 *
  32 *                     All Rights Reserved                      *
  33 *                                                              *
  34 *           This software is licensed by AT&T Corp.            *
  35 *       under the terms and conditions of the license in       *
  36 *       http://www.research.att.com/orgs/ssr/book/reuse        *
  37 *                                                              *
  38 *               This software was created by the               *
  39 *           Software Engineering Research Department           *
  40 *                    AT&T Bell Laboratories                    *
  41 *                                                              *
  42 *               For further information contact                *
  43 *                     gsf@research.att.com                     *
  44 *                                                              *
  45 ***************************************************************/
  46 #include        "sfhdr.h"
  47
  48 /*      Write out a double value in a portable format
  49 **
  50 **      Written by Kiem-Phong Vo (08/05/90)
  51 */
  52
  53 #if __STD_C
  54 _sfputd(Sfio_t* f, reg double v)
  55 #else
  56 _sfputd(f,v)
  57 Sfio_t          *f;
  58 reg double      v;
  59 #endif
  60 {
  61 #define N_ARRAY         (16*sizeof(double))
  62         reg int         n, w;
  63         reg double      x;
  64         reg uchar       *s, *ends;
  65         int             exp;
  66         uchar           c[N_ARRAY];
  67
  68         if(f->mode != SF_WRITE && _sfmode(f,SF_WRITE,0) < 0)
  69                 return -1;
  70         SFLOCK(f,0);
  71
  72         /* get the sign of v */
  73         if(v < 0.)
  74         {       v = -v;
  75                 n = 1;
  76         }
  77         else    n = 0;
  78
  79         /* make the magnitude of v < 1 */
  80         if(v != 0.)
  81                 v = frexp(v,&exp);
  82         else    exp = 0;
  83
  84         /* code the sign of v and exp */
  85         if((w = exp) < 0)
  86         {       n |= 02;
  87                 w = -w;
  88         }
  89
  90         /* write out the signs and the exp */
  91         SFOPEN(f,0);
  92         if(sfputc(f,n) < 0 || (w = sfputu(f,w)) < 0)
  93                 return -1;
  94         SFLOCK(f,0);
  95         w += 1;
  96
  97         s = (ends = &c[0])+sizeof(c);
  98         while(s > ends)
  99         {       /* get 2^SF_PRECIS precision at a time */
 100                 n = (int)(x = ldexp(v,SF_PRECIS));
 101                 *--s = n|SF_MORE;
 102                 if((v = x-n) <= 0.)
 103                         break;
 104         }
 105
 106         /* last byte is not SF_MORE */
 107         ends = &c[0] + sizeof(c) -1;
 108         *ends &= ~SF_MORE;
 109
 110         /* write out coded bytes */
 111         n = ends - s + 1;
 112         w = SFWRITE(f,(Void_t*)s,n) == n ? w+n : -1;
 113
 114         SFOPEN(f,0);
 115         return w;
 116 }