ack/lang/pc/libpc/wrr.c

/* $Id$ */
/*
 * (c) copyright 1983 by the Vrije Universiteit, Amsterdam, The Netherlands.
 *
 *          This product is part of the Amsterdam Compiler Kit.
 *
 * Permission to use, sell, duplicate or disclose this software must be
 * obtained in writing. Requests for such permissions may be sent to
 *
 *      Dr. Andrew S. Tanenbaum
 *      Wiskundig Seminarium
 *      Vrije Universiteit
 *      Postbox 7161
 *      1007 MC Amsterdam
 *      The Netherlands
 *
 */

/* Author: J.W. Stevenson */

#include <pc_err.h>
#include <pc_file.h>

extern _wstrin();
extern char* _ecvt();

#define PREC_DIG 80 /* maximum digits produced by _ecvt() */

_wsr(w, r, f) int w;
double r;
struct file* f;
{
	char *p, *b;
	int s, d, i;
	char buf[PREC_DIG + 7];

	if (w < 0)
		_trp(EWIDTH);
	p = buf;
	if ((i = w - 6) < 2)
		i = 2;
	b = _ecvt(r, i, &d, &s);
	*p++ = s ? '-' : ' ';
	if (*b == '0')
		d++;
	*p++ = *b++;
	*p++ = '.';
	while (--i > 0)
		*p++ = *b++;
	*p++ = 'e';
	d--;
	if (d < 0)
	{
		d = -d;
		*p++ = '-';
	}
	else
		*p++ = '+';

	if (d >= 1000)
	{
		*p++ = '*';
		*p++ = '*';
		*p++ = '*';
	}
	else
	{
		*p++ = '0' + d / 100;
		*p++ = '0' + (d / 10) % 10;
		*p++ = '0' + d % 10;
	}
	_wstrin(w, (int)(p - buf), buf, f);
}

_wrr(r, f) double r;
struct file* f;
{
	_wsr(13, r, f);
}