1#define _GNU_SOURCE
 2#include <stdlib.h>
 3#include <stdio.h>
 4
 5char *ecvt(double x, int n, int *dp, int *sign)
 6{
 7	static char buf[16];
 8	char tmp[32];
 9	int i, j;
10
11	if (n-1U > 15) n = 15;
12	sprintf(tmp, "%.*e", n-1, x);
13	i = *sign = (tmp[0]=='-');
14	for (j=0; tmp[i]!='e'; j+=(tmp[i++]!='.'))
15		buf[j] = tmp[i];
16	buf[j] = 0;
17	*dp = atoi(tmp+i+1)+1;
18
19	return buf;
20}