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Revision 1.3, Sat Jan 7 18:40:56 2012 UTC (8 years, 5 months ago) by christos
Branch: MAIN
CVS Tags: yamt-pagecache-base9, yamt-pagecache-base8, yamt-pagecache-base7, yamt-pagecache-base6, yamt-pagecache-base5, yamt-pagecache-base4, tls-maxphys-base, tls-maxphys, tls-earlyentropy-base, tls-earlyentropy, riastradh-xf86-video-intel-2-7-1-pre-2-21-15, riastradh-drm2-base3, riastradh-drm2-base2, riastradh-drm2-base1, riastradh-drm2-base, riastradh-drm2, prg-localcount2-base3, prg-localcount2-base2, prg-localcount2-base1, prg-localcount2-base, prg-localcount2, phil-wifi-base, phil-wifi-20200421, phil-wifi-20200411, phil-wifi-20200406, phil-wifi-20191119, phil-wifi-20190609, phil-wifi, pgoyette-localcount-base, pgoyette-localcount-20170426, pgoyette-localcount-20170320, pgoyette-localcount-20170107, pgoyette-localcount-20161104, pgoyette-localcount-20160806, pgoyette-localcount-20160726, pgoyette-localcount, pgoyette-compat-merge-20190127, pgoyette-compat-base, pgoyette-compat-20190127, pgoyette-compat-20190118, pgoyette-compat-1226, pgoyette-compat-1126, pgoyette-compat-1020, pgoyette-compat-0930, pgoyette-compat-0906, pgoyette-compat-0728, pgoyette-compat-0625, pgoyette-compat-0521, pgoyette-compat-0502, pgoyette-compat-0422, pgoyette-compat-0415, pgoyette-compat-0407, pgoyette-compat-0330, pgoyette-compat-0322, pgoyette-compat-0315, pgoyette-compat, perseant-stdc-iso10646-base, perseant-stdc-iso10646, netbsd-9-base, netbsd-9-0-RELEASE, netbsd-9-0-RC2, netbsd-9-0-RC1, netbsd-9, netbsd-8-base, netbsd-8-2-RELEASE, netbsd-8-1-RELEASE, netbsd-8-1-RC1, netbsd-8-0-RELEASE, netbsd-8-0-RC2, netbsd-8-0-RC1, netbsd-8, netbsd-7-nhusb-base-20170116, netbsd-7-nhusb-base, netbsd-7-nhusb, netbsd-7-base, netbsd-7-2-RELEASE, netbsd-7-1-RELEASE, netbsd-7-1-RC2, netbsd-7-1-RC1, netbsd-7-1-2-RELEASE, netbsd-7-1-1-RELEASE, netbsd-7-1, netbsd-7-0-RELEASE, netbsd-7-0-RC3, netbsd-7-0-RC2, netbsd-7-0-RC1, netbsd-7-0-2-RELEASE, netbsd-7-0-1-RELEASE, netbsd-7-0, netbsd-7, netbsd-6-base, netbsd-6-1-RELEASE, netbsd-6-1-RC4, netbsd-6-1-RC3, netbsd-6-1-RC2, netbsd-6-1-RC1, netbsd-6-1-5-RELEASE, netbsd-6-1-4-RELEASE, netbsd-6-1-3-RELEASE, netbsd-6-1-2-RELEASE, netbsd-6-1-1-RELEASE, netbsd-6-1, netbsd-6-0-RELEASE, netbsd-6-0-RC2, netbsd-6-0-RC1, netbsd-6-0-6-RELEASE, netbsd-6-0-5-RELEASE, netbsd-6-0-4-RELEASE, netbsd-6-0-3-RELEASE, netbsd-6-0-2-RELEASE, netbsd-6-0-1-RELEASE, netbsd-6-0, netbsd-6, matt-nb8-mediatek-base, matt-nb8-mediatek, matt-nb6-plus-nbase, matt-nb6-plus-base, matt-nb6-plus, localcount-20160914, is-mlppp-base, is-mlppp, bouyer-socketcan-base1, bouyer-socketcan-base, bouyer-socketcan, agc-symver-base, agc-symver, HEAD
Changes since 1.2: +37 -2 lines

- add strspct
- be explicit about string not being NUL terminated if bufsiz == 0

/* $NetBSD: strpct.c,v 1.3 2012/01/07 18:40:56 christos Exp $ */

/*-
 * Copyright (c) 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Erik E. Fair
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Calculate a percentage without resorting to floating point
 * and return a pointer to a string
 *
 * "digits" is the number of digits past the decimal place you want
 * (zero being the straight percentage with no decimals)
 *
 * Erik E. Fair <fair@clock.org>, May 8, 1997
 */

#include <sys/cdefs.h>
__RCSID("$NetBSD: strpct.c,v 1.3 2012/01/07 18:40:56 christos Exp $");

#include <stdint.h>
#include <locale.h>
#include <limits.h>
#include <stdio.h>
#include <errno.h>
#include <util.h>

char *
strspct(char *buf, size_t bufsiz, intmax_t numerator, intmax_t denominator,
    size_t digits)
{
	int sign;

	switch (bufsiz) {
	case 1:
		*buf = '\0';
		/*FALLTHROUGH*/
	case 0:
		return buf;
	default:
		break;
	}

	if (denominator < 0) {
		denominator = -denominator;
		sign = 1;
	} else
		sign = 0;

	if (numerator < 0) {
		numerator = -numerator;
		sign++;
	}

	sign &= 1;
	(void)strpct(buf + sign, bufsiz - sign, (uintmax_t)numerator,
	    (uintmax_t)denominator, digits);
	if (sign)
		*buf = '-';
	return buf;
}

char *
strpct(char *buf, size_t bufsiz, uintmax_t numerator, uintmax_t denominator,
    size_t digits)
{
	uintmax_t factor, result;
	size_t u;

	factor = 100;
	for (u = 0; u < digits; u++) {
		/* watch out for overflow! */
		if (factor < (UINTMAX_MAX / 10))
			factor *= 10;
		else
			break;
	}

	/* watch out for overflow! */
	if (numerator < (UINTMAX_MAX / factor))
		numerator *= factor;
	else {
		/* toss some of the bits of lesser significance */
		denominator /= factor;
	}

	if (denominator == 0)
		denominator = 1;

	result = numerator / denominator;

	if (digits == 0)
		(void)snprintf(buf, bufsiz, "%ju", result);
	else {
		factor /= 100;		/* undo initialization */

		(void)snprintf(buf, bufsiz, "%ju%s%0*ju",
		    result / factor, localeconv()->decimal_point, (int)u,
		    result % factor);
	}       

	return buf;
}