/*-

 * Copyright (c) 2007 Eric Anderson <anderson@FreeBSD.org>

 * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>

 * All rights reserved.

 *

 * 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 AUTHORS 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 AUTHORS 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.

 */

#include <sys/cdefs.h>

__FBSDID("$FreeBSD: head/lib/libutil/expand_number.c 211343 2010-08-15 18:32:06Z des $");

#include <sys/types.h>

#include <ctype.h>

#include <errno.h>

#include <inttypes.h>

//#include <libutil.h>

#include <stdint.h>

/*

 * Convert an expression of the following forms to a uint64_t.

 *  1) A positive decimal number.

 *  2) A positive decimal number followed by a 'b' or 'B' (mult by 1).

 *  3) A positive decimal number followed by a 'k' or 'K' (mult by 1 << 10).

 *  4) A positive decimal number followed by a 'm' or 'M' (mult by 1 << 20).

 *  5) A positive decimal number followed by a 'g' or 'G' (mult by 1 << 30).

 *  6) A positive decimal number followed by a 't' or 'T' (mult by 1 << 40).

 *  7) A positive decimal number followed by a 'p' or 'P' (mult by 1 << 50).

 *  8) A positive decimal number followed by a 'e' or 'E' (mult by 1 << 60).

 */

int

expand_number(const char *buf, uint64_t *num)

{

  uint64_t number;

  unsigned shift;

  char *endptr;

  number = strtoumax(buf, &endptr, 0);

  if (endptr == buf) {

    /* No valid digits. */

    errno = EINVAL;

    return (-1);

  }

  switch (tolower((unsigned char)*endptr)) {

  case 'e':

    shift = 60;

    break;

  case 'p':

    shift = 50;

    break;

  case 't':

    shift = 40;

    break;

  case 'g':

    shift = 30;

    break;

  case 'm':

    shift = 20;

    break;

  case 'k':

    shift = 10;

    break;

  case 'b':

  case '\0': /* No unit. */

    *num = number;

    return (0);

  default:

    /* Unrecognized unit. */

    errno = EINVAL;

    return (-1);

  }

  if ((number << shift) >> shift != number) {

    /* Overflow */

    errno = ERANGE;

    return (-1);

  }

  *num = number << shift;

  return (0);

}