strtol.c

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/*
 * Copyright (c) 1994-1995, 1998 University of Utah and the Flux Group.
 * All rights reserved.
 * 
 * This file is part of the Flux OSKit.  The OSKit is free software, also known
 * as "open source;" you can redistribute it and/or modify it under the terms
 * of the GNU General Public License (GPL), version 2, as published by the Free
 * Software Foundation (FSF).  To explore alternate licensing terms, contact
 * the University of Utah at [e-mail] or [phone].
 * 
 * The OSKit 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 GPL for more details.  You should have
 * received a copy of the GPL along with the OSKit; see the file COPYING.  If
 * not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
 */

#include <ctype.h>
#include <string.h>

long strtol(const char *p, char **out_p, int base)
{
	long v = 0;
	int is_neg = 0;

	while (isspace(*p))
		p++;
	if (*p == '-')
		is_neg = 1, p++;
	else if (*p == '+')
		is_neg = 0;
	if (((base == 16) || (base == 0)) &&
	    ((*p == '0') && ((p[1] == 'x') || (p[1] == 'X'))))
	{
		p += 2;
		base = 16;
	}
	if (base == 0)
	{
		if (*p == '0')
			base = 8;
		else
			base = 10;
	}
	while (1)
	{
		char c = *p;
		if ((c >= '0') && (c <= '9') && (c - '0' < base))
			v = (v * base) + (c - '0');
		else if ((c >= 'a') && (c <= 'z') && (c - 'a' + 10 < base))
			v = (v * base) + (c - 'a' + 10);
		else if ((c >= 'A') && (c <= 'Z') && (c - 'A' + 10 < base))
			v = (v * base) + (c - 'A' + 10);
		else
			break;
		p++;
	}
	if (is_neg)
		v = -v;
	if (out_p) *out_p = (char*)p;
	return v;
}