procps/lib/strutils.c

/*
 * strutils.c - various string routines shared by commands
 * This file was copied from util-linux at fall 2011.
 *
 * Copyright (C) 2010 Karel Zak <kzak@redhat.com>
 * Copyright (C) 2010 Davidlohr Bueso <dave@gnu.org>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include <stdlib.h>
#include <ctype.h>

#include "c.h"
#include "strutils.h"

/*
 * same as strtol(3) but exit on failure instead of returning crap
 */
long strtol_or_err(const char *str, const char *errmesg)
{
	long num;
	char *end = NULL;

	if (str != NULL && *str != '\0') {
		errno = 0;
		num = strtol(str, &end, 10);
		if (errno == 0 && str != end && end != NULL && *end == '\0')
			return num;
	}
	error(EXIT_FAILURE, errno, "%s: '%s'", errmesg, str);
	return 0;
}

/*
 * same as strtod(3) but exit on failure instead of returning crap
 */
double strtod_or_err(const char *str, const char *errmesg)
{
	double num;
	char *end = NULL;

	if (str != NULL && *str != '\0') {
		errno = 0;
		num = strtod(str, &end);
		if (errno == 0 && str != end && end != NULL && *end == '\0')
			return num;
	}
	error(EXIT_FAILURE, errno, "%s: '%s'", errmesg, str);
	return 0;
}

/*
 * Covert a string into a double in a non-locale aware way.
 * This means the decimal point can be either . or ,
 * Also means you cannot use the other for thousands separator
 *
 * Exits on failure like its other _or_err cousins
 */
double strtod_nol_or_err(char *str, const char *errmesg)
{
    double num;
    const char *cp, *radix;
    double mult;
    int negative = 0;

    if (str != NULL && *str != '\0') {
        num = 0.0;
        cp = str;
        /* strip leading spaces */
        while (isspace(*cp))
            cp++;

        /* get sign */
        if (*cp == '-') {
            negative = 1;
            cp++;
        } else if (*cp == '+')
            cp++;

        /* find radix */
        radix = cp;
        mult=0.1;
        while(isdigit(*radix)) {
            radix++;
            mult *= 10;
        }
        while(isdigit(*cp)) {
            num += (*cp - '0') * mult;
            mult /= 10;
            cp++;
        }
        /* got the integers */
        if (*cp == '\0')
            return (negative?-num:num);
        if (*cp != '.' && *cp != ',')
            error(EXIT_FAILURE, EINVAL, "%s: '%s'", errmesg, str);

        cp++;
        mult = 0.1;
        while(isdigit(*cp)) {
            num += (*cp - '0') * mult;
            mult /= 10;
            cp++;
        }
        if (*cp == '\0')
            return (negative?-num:num);
    }
    error(EXIT_FAILURE, errno, "%s: '%s'", errmesg, str);
    return 0;
}