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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;
}