[apple/libc.git] / stdlib / OpenBSD / gcvt.c

/*	$OpenBSD: gcvt.c,v 1.11 2009/10/16 12:15:03 martynas Exp $	*/

/*
 * Copyright (c) 2002, 2003, 2006 Todd C. Miller <Todd.Miller@courtesan.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Sponsored in part by the Defense Advanced Research Projects
 * Agency (DARPA) and Air Force Research Laboratory, Air Force
 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
 */

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

extern char *__dtoa(double, int, int, int *, int *, char **);
extern void  __freedtoa(char *);

char *
gcvt(double value, int ndigit, char *buf)
{
	char *digits, *dst, *src;
	int i, decpt, sign;
	struct lconv *lconv;

	lconv = localeconv();
	if (ndigit == 0) {
		buf[0] = '\0';
		return (buf);
	}

	digits = __dtoa(value, 2, ndigit, &decpt, &sign, NULL);
	if (digits == NULL)
		return (NULL);
	if (decpt == 9999) {
		/*
		 * Infinity or NaN, convert to inf or nan with sign.
		 * We assume the buffer is at least ndigit long.
		 */
		snprintf(buf, ndigit + 1, "%s%s", sign ? "-" : "",
		    *digits == 'I' ? "inf" : "nan");
		__freedtoa(digits);
		return (buf);
	}

	dst = buf;
	if (sign)
		*dst++ = '-';

	if (decpt < 0 || decpt > ndigit) {
		/* exponential format (e.g. 1.2345e+13) */
		if (--decpt < 0) {
			sign = 1;
			decpt = -decpt;
		} else
			sign = 0;
		src = digits;
		*dst++ = *src++;
		dst = stpcpy(dst, lconv->decimal_point);
		while (*src != '\0')
			*dst++ = *src++;
		*dst++ = 'e';
		if (sign)
			*dst++ = '-';
		else
			*dst++ = '+';
		if (decpt < 10) {
			*dst++ = '0';
			*dst++ = '0' + decpt;
			*dst = '\0';
		} else {
			/* XXX - optimize */
			for (sign = decpt, i = 0; (sign /= 10) != 0; i++)
				continue;
			dst[i + 1] = '\0';
			while (decpt != 0) {
				dst[i--] = '0' + decpt % 10;
				decpt /= 10;
			}
		}
	} else {
		/* standard format */
		for (i = 0, src = digits; i < decpt; i++) {
			if (*src != '\0')
				*dst++ = *src++;
			else
				*dst++ = '0';
		}
		if (*src != '\0') {
			if (src == digits)
				*dst++ = '0';	/* zero before decimal point */
			dst = stpcpy(dst, lconv->decimal_point);
			for (i = decpt; digits[i] != '\0'; i++) {
				*dst++ = digits[i];
			}
		}
		*dst = '\0';
	}
	__freedtoa(digits);
	return (buf);
}
Commit	Line	Data
1f2f436a	1	/* $OpenBSD: gcvt.c,v 1.11 2009/10/16 12:15:03 martynas Exp $ */
3d9156a7 A	2
3d9156a7 A	3	/*
1f2f436a	4	* Copyright (c) 2002, 2003, 2006 Todd C. Miller <Todd.Miller@courtesan.com>
3d9156a7 A	5	*
	6	* Permission to use, copy, modify, and distribute this software for any
	7	* purpose with or without fee is hereby granted, provided that the above
	8	* copyright notice and this permission notice appear in all copies.
	9	*
	10	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	11	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	12	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	13	* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	14	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
	15	* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
	16	* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	17	*
	18	* Sponsored in part by the Defense Advanced Research Projects
	19	* Agency (DARPA) and Air Force Research Laboratory, Air Force
	20	* Materiel Command, USAF, under agreement number F39502-99-1-0512.
	21	*/
	22
1f2f436a	23	#include <locale.h>
3d9156a7 A	24	#include <stdio.h>
	25	#include <stdlib.h>
	26	#include <string.h>
	27
	28	extern char __dtoa(double, int, int, int , int , char *);
1f2f436a	29	extern void __freedtoa(char *);
3d9156a7 A	30
	31	char *
	32	gcvt(double value, int ndigit, char *buf)
	33	{
	34	char digits, dst, *src;
	35	int i, decpt, sign;
1f2f436a	36	struct lconv *lconv;
3d9156a7	37
1f2f436a	38	lconv = localeconv();
3d9156a7 A	39	if (ndigit == 0) {
	40	buf[0] = '\0';
	41	return (buf);
	42	}
	43
	44	digits = __dtoa(value, 2, ndigit, &decpt, &sign, NULL);
1f2f436a A	45	if (digits == NULL)
1f2f436a A	46	return (NULL);
3d9156a7	47	if (decpt == 9999) {
1f2f436a A	48	/*
	49	* Infinity or NaN, convert to inf or nan with sign.
	50	* We assume the buffer is at least ndigit long.
	51	*/
	52	snprintf(buf, ndigit + 1, "%s%s", sign ? "-" : "",
	53	*digits == 'I' ? "inf" : "nan");
	54	__freedtoa(digits);
3d9156a7 A	55	return (buf);
	56	}
	57
	58	dst = buf;
	59	if (sign)
	60	*dst++ = '-';
	61
	62	if (decpt < 0 \|\| decpt > ndigit) {
1f2f436a	63	/* exponential format (e.g. 1.2345e+13) */
3d9156a7 A	64	if (--decpt < 0) {
	65	sign = 1;
	66	decpt = -decpt;
	67	} else
	68	sign = 0;
1f2f436a A	69	src = digits;
1f2f436a A	70	dst++ = src++;
ad3c9f2a	71	dst = stpcpy(dst, lconv->decimal_point);
1f2f436a	72	while (*src != '\0')
3d9156a7 A	73	dst++ = src++;
	74	*dst++ = 'e';
	75	if (sign)
	76	*dst++ = '-';
	77	else
	78	*dst++ = '+';
	79	if (decpt < 10) {
	80	*dst++ = '0';
	81	*dst++ = '0' + decpt;
	82	*dst = '\0';
	83	} else {
	84	/* XXX - optimize */
	85	for (sign = decpt, i = 0; (sign /= 10) != 0; i++)
1f2f436a A	86	continue;
1f2f436a A	87	dst[i + 1] = '\0';
3d9156a7 A	88	while (decpt != 0) {
	89	dst[i--] = '0' + decpt % 10;
	90	decpt /= 10;
	91	}
	92	}
	93	} else {
	94	/* standard format */
	95	for (i = 0, src = digits; i < decpt; i++) {
	96	if (*src != '\0')
	97	dst++ = src++;
	98	else
	99	*dst++ = '0';
	100	}
	101	if (*src != '\0') {
1f2f436a A	102	if (src == digits)
1f2f436a A	103	dst++ = '0'; / zero before decimal point */
ad3c9f2a	104	dst = stpcpy(dst, lconv->decimal_point);
3d9156a7 A	105	for (i = decpt; digits[i] != '\0'; i++) {
	106	*dst++ = digits[i];
	107	}
	108	}
	109	*dst = '\0';
	110	}
1f2f436a	111	__freedtoa(digits);
3d9156a7 A	112	return (buf);
3d9156a7 A	113	}