77 lines
1.2 KiB
C
77 lines
1.2 KiB
C
/* $Id$ */
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/*
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* (c) copyright 1983 by the Vrije Universiteit, Amsterdam, The Netherlands.
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*
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* This product is part of the Amsterdam Compiler Kit.
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*
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* Permission to use, sell, duplicate or disclose this software must be
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* obtained in writing. Requests for such permissions may be sent to
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*
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* Dr. Andrew S. Tanenbaum
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* Wiskundig Seminarium
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* Vrije Universiteit
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* Postbox 7161
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* 1007 MC Amsterdam
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* The Netherlands
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*
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*/
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/* Author: J.W. Stevenson */
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#include "pc.h"
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#define BIG 1e17
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static double r;
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static int pow10;
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static void dig(int ch)
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{
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if (r > BIG)
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pow10++;
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else
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r = r * 10.0 + ch;
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}
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double _rdr(struct file* f)
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{
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int i;
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double e;
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int is_signed, ch;
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r = 0;
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pow10 = 0;
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_rf(f);
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_skipsp(f);
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is_signed = _getsig(f);
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ch = _fstdig(f);
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do
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dig(ch);
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while ((ch = _nxtdig(f)) >= 0);
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if (*f->ptr == '.')
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{
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_incpt(f);
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ch = _fstdig(f);
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do
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{
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dig(ch);
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pow10--;
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} while ((ch = _nxtdig(f)) >= 0);
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}
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if ((*f->ptr == 'e') || (*f->ptr == 'E'))
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{
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_incpt(f);
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pow10 += _getint(f);
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}
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if ((i = pow10) < 0)
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i = -i;
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e = 1.0;
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while (--i >= 0)
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e *= 10.0;
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if (pow10 < 0)
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r /= e;
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else
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r *= e;
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return (is_signed ? -r : r);
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}
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