/* test-printf-round.c */

#define _POSIX_SOURCE
#define _XOPEN_SOURCE	600

#include <stdio.h>
#include <stdlib.h>
#include <string.h>



#if 0
#define V		0X1.52f8a8e32e982P+140
#define V		0X0.0000000000000P+0
#endif
#define V		0X1.52f8a8e32e982P-140
#define DECIMALS	43



int
main(void)
{
    int		decpt		= 0;
    int		sgn		= -1;
    char	*b;
    static char zeros[128]	= 
	"0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000";
    static char buf[128]	= { 0 };

    b = fcvtbuf(V, DECIMALS, &decpt, &sgn, buf);

    printf("sgn %d decpt %d %s%.*s%s%s %.*f\n",
		sgn, decpt,
		    !sgn ? "+" : 1 == sgn ? "-" : "",
			/* 0 < decpt -> decpt digits | . | buf + decpt digits */
			/* decpt < 0 -> 0. | decpt zeros | buf digits */
			decpt < 0 ? 2 : decpt,
			    decpt < 0 ? "0." : b,
				decpt < 0 ? zeros + strlen(zeros) + decpt : ".",
				    decpt < 0 ? b : b + decpt,
					DECIMALS, V);
}