/*  $OpenBSD: strtonum.c,v 1.8 2015/09/13 08:31:48 guenther Exp $ */

/*

 * Copyright (c) 2004 Ted Unangst and Todd Miller

 * All rights reserved.

 *

 * 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.

 */

#include <errno.h>

#include <limits.h>

#include <stdlib.h>

#define INVALID   1

#define TOOSMALL  2

#define TOOLARGE  3

long long

strtonum(const char *numstr, long long minval, long long maxval,

    const char **errstrp)

{

  long long ll = 0;

  int error = 0;

  char *ep;

  struct errval {

    const char *errstr;

    int err;

  } ev[4] = {

    { NULL,   0 },

    { "invalid",  EINVAL },

    { "too small",  ERANGE },

    { "too large",  ERANGE },

  };

  ev[0].err = errno;

  errno = 0;

  if (minval > maxval) {

    error = INVALID;

  } else {

    ll = strtoll(numstr, &ep, 10);

    if (numstr == ep || *ep != '\0')

      error = INVALID;

    else if ((ll == LLONG_MIN && errno == ERANGE) || ll < minval)

      error = TOOSMALL;

    else if ((ll == LLONG_MAX && errno == ERANGE) || ll > maxval)

      error = TOOLARGE;

  }

  if (errstrp != NULL)

    *errstrp = ev[error].errstr;

  errno = ev[error].err;

  if (error)

    ll = 0;

  return (ll);

}