github.com/afumu/libc@v0.0.6/musl/src/stdlib/ecvt.c (about)

     1  #define _GNU_SOURCE
     2  #include <stdlib.h>
     3  #include <stdio.h>
     4  
     5  char *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  }