lib/ack/libp/wrf.c

   1 /* $Header$ */
   2 /*
   3  * (c) copyright 1983 by the Vrije Universiteit, Amsterdam, The Netherlands.
   4  *
   5  *          This product is part of the Amsterdam Compiler Kit.
   6  *
   7  * Permission to use, sell, duplicate or disclose this software must be
   8  * obtained in writing. Requests for such permissions may be sent to
   9  *
  10  *      Dr. Andrew S. Tanenbaum
  11  *      Wiskundig Seminarium
  12  *      Vrije Universiteit
  13  *      Postbox 7161
  14  *      1007 MC Amsterdam
  15  *      The Netherlands
  16  *
  17  */
  18
  19 /* Author: J.W. Stevenson */
  20
  21 #include        <pc_err.h>
  22 #include        <pc_file.h>
  23
  24 extern          _wstrin();
  25 extern char     *_fcvt();
  26
  27 #define assert(x)       /* nothing */
  28
  29 #if __STDC__
  30 #include <float.h>
  31 #define HUGE_DIG        DBL_MAX_10_EXP  /* log10(maxreal) */
  32 #else
  33 #define HUGE_DIG        400     /* log10(maxreal) */
  34 #endif
  35 #define PREC_DIG        80      /* the maximum digits returned by _fcvt() */
  36 #define FILL_CHAR       '0'     /* char printed if all of _fcvt() used */
  37 #define BUFSIZE         HUGE_DIG + PREC_DIG + 3
  38
  39 _wrf(n,w,r,f) int n,w; double r; struct file *f; {
  40         char *p,*b; int s,d; char buf[BUFSIZE];
  41
  42         if ( n < 0 || w < 0) _trp(EWIDTH);
  43         p = buf;
  44         if (n > PREC_DIG)
  45                 n = PREC_DIG;
  46         b = _fcvt(r,n,&d,&s);
  47         assert(abs(d) <= HUGE_DIG);
  48         if (s)
  49                 *p++ = '-';
  50         if (d<=0)
  51                 *p++ = '0';
  52         else
  53                 do
  54                         *p++ = (*b ? *b++ : FILL_CHAR);
  55                 while (--d > 0);
  56         if (n > 0)
  57                 *p++ = '.';
  58         while (++d <= 0) {
  59                 if (--n < 0)
  60                         break;
  61                 *p++ = '0';
  62         }
  63         while (--n >= 0) {
  64                 *p++ = (*b ? *b++ : FILL_CHAR);
  65                 assert(p <= buf+BUFSIZE);
  66         }
  67         _wstrin(w,(int)(p-buf),buf,f);
  68 }