glibc/misc/efgcvt.c

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/* [efg]cvt -- compatibility functions for floating point formatting
Copyright (C) 1995 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <math.h>
char *
fcvt (value, ndigit, decpt, sign)
double value;
int ndigit, *decpt, *sign;
{
static char buf[100];
int n, i;
*sign = value < 0.0;
if (*sign)
value = - value;
n = snprintf (buf, sizeof buf, "%.*f", ndigit, value);
if (n < 0)
return NULL;
i = 0;
while (i < n && isdigit (buf[i]))
++i;
*decpt = i;
do
++i;
while (! isdigit (buf[i]));
memmove (&buf[i - *decpt], buf, n - (i - *decpt));
return buf;
}
char *
ecvt (value, ndigit, decpt, sign)
double value;
int ndigit, *decpt, *sign;
{
ndigit -= (int) floor (log10 (value));
if (ndigit < 0)
ndigit = 0;
return fcvt (value, ndigit, decpt, sign);
}
char *
gcvt (value, ndigit, buf)
double value;
int ndigit;
char *buf;
{
sprintf (buf, "%.*g", ndigit, value);
return buf;
}