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/*

 * strtol.c - This file is part of the libc-8086 package for ELKS,

 * Copyright (C) 1995, 1996 Nat Friedman <ndf@linux.mit.edu>.

 *

 *  This library is free software; you can redistribute it and/or

 *  modify it under the terms of the GNU Library General Public

 *  License as published by the Free Software Foundation; either

 *  version 2 of the License, or (at your option) any later version.

 *

 *  This library 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

 *  Library General Public License for more details.

 *

 *  You should have received a copy of the GNU Library General Public

 *  License along with this library; if not, write to the Free

 *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

 *

 */

#include <ctype.h>

#include <stdlib.h>

long int

strtol(const char *nptr, char **endptr, int base)

{

  const char * ptr;

  unsigned short negative;

  long int number;

  ptr=nptr;

  while (isspace(*ptr))

    ptr++;

  negative=0;

  if (*ptr=='-')

    negative=1;

  number=(long int)strtoul(nptr, endptr, base);

  return (negative ? -number:number);

}

unsigned long int

strtoul(const char *nptr, char **endptr, int base)

{

  unsigned long int number;

  /* Sanity check the arguments */

  if (base==1 || base>36 || base<0)

    base=0;

  /* advance beyond any leading whitespace */

  while (isspace(*nptr))

    nptr++;

  /* check for optional '+' or '-' */

  if (*nptr=='-')

      nptr++;

  else

    if (*nptr=='+')

      nptr++;

  /* If base==0 and the string begins with "0x" then we're supposed

     to assume that it's hexadecimal (base 16). */

  else

    if (base==0 && *nptr=='0')

      if (toupper(*(nptr+1))=='X')

        {

          base=16;

          nptr+=2;

        }

  /* If base==0 and the string begins with "0" but not "0x",

     then we're supposed to assume that it's octal (base 8). */

      else

        {

          base=8;

          nptr++;

        }

  /* If base is still 0 (it was 0 to begin with and the string didn't begin

     with "0"), then we are supposed to assume that it's base 10 */

  if (base==0)

    base=10;

  number=0;

  while (isalnum(*nptr))

    {

      number= (number*base)+((isalpha(*nptr) ? toupper(*nptr) : *nptr)

                             - (isdigit(*nptr) ? '0' : 'A' - 10));

      nptr++;

      /*if (*nptr>'0'+base)

        break;*/

    }

  /* Some code is simply _impossible_ to write with -Wcast-qual .. :-\ */

  if (endptr!=NULL)

    *endptr=(char *)nptr;

  /* All done */

  return number;

}