strtol.c

MIPS下的boottloader yamon 的源代码

/************************************************************************
 *
 *  strtol.c
 *
 *  Note: signed long is assumed to equal INT32.
 *
 *
 * ######################################################################
 *
 * Copyright (c) 1999-2000 MIPS Technologies, Inc. All rights reserved. 
 * 
 * Unpublished rights reserved under the Copyright Laws of the United States of 
 * America. 
 * 
 * This document contains information that is proprietary to MIPS Technologies, 
 * Inc. ("MIPS Technologies"). Any copying, modifying or use of this information 
 * (in whole or in part) which is not expressly permitted in writing by MIPS 
 * Technologies or a contractually-authorized third party is strictly 
 * prohibited. At a minimum, this information is protected under unfair 
 * competition laws and the expression of the information contained herein is 
 * protected under federal copyright laws. Violations thereof may result in 
 * criminal penalties and fines. 
 * MIPS Technologies or any contractually-authorized third party reserves the 
 * right to change the information contained in this document to improve 
 * function, design or otherwise. MIPS Technologies does not assume any 
 * liability arising out of the application or use of this information. Any 
 * license under patent rights or any other intellectual property rights owned 
 * by MIPS Technologies or third parties shall be conveyed by MIPS Technologies 
 * or any contractually-authorized third party in a separate license agreement 
 * between the parties. 
 * The information contained in this document constitutes one or more of the 
 * following: commercial computer software, commercial computer software 
 * documentation or other commercial items. If the user of this information, or 
 * any related documentation of any kind, including related technical data or 
 * manuals, is an agency, department, or other entity of the United States 
 * government ("Government"), the use, duplication, reproduction, release, 
 * modification, disclosure, or transfer of this information, or any related 
 * documentation of any kind, is restricted in accordance with Federal 
 * Acquisition Regulation 12.212 for civilian agencies and Defense Federal 
 * Acquisition Regulation Supplement 227.7202 for military agencies. The use of 
 * this information by the Government is further restricted in accordance with 
 * the terms of the license agreement(s) and/or applicable contract terms and 
 * conditions covering this information from MIPS Technologies or any 
 * contractually-authorized third party. 
 *
 ************************************************************************/

#include <ctype.h>
#include <sysdefs.h>
#include <errno.h>

#define	 max_allowable(A) 	 (MAXINT(sizeof(INT32))/A - 1)


long strtol(
	const 	char 	*str, 
		char 	**endptr, 
		int 	base)
{
	long  	i = 0;
	int   	s = 1;
	int 	c;
	
	/* skip white space */
	while(isspace(*str)) {
		str++;
	}
	
	/* sign flag check */
	if (*str == '+') str++;
	else if (*str == '-') {
		s = -1;
		str++;
	}

	if (*str == '0') {
		if (toupper(*++str) == 'X')	base = 16,str++;
		else if (base == 0)		base = 8;
		}
	if (base == 0) base = 10;
	
	
	if (base <= 10)
	/* digit str to number */
		for (; isdigit(*str); str++) {
			if (i < max_allowable(base))
				i = i * base + (*str - '0');
			else {
				i = MAXINT(sizeof(INT32));
				errno = ERANGE;
			}
		}
	else if (base > 10) {
		for (; c = *str; str++) {
			if (isdigit(c))
			 	c = c - '0';
			else {
				c = toupper(c);

				if (c >= 'A' && c < ('A' - 10 + base))
				 	c = c - 'A' + 10;
				else
				 	break;
			}
			if (i < max_allowable(base))
			 	i = i * base + c;
			else {
			 	i = MAXINT(sizeof(INT32));
				errno = ERANGE;
			}
		}
	}	
 	else
	 	return 0;		/* negative base is not allowed */
	
	if (endptr) *endptr = (char *) str;

	if (s == -1)
		i = -i;

	return i;
}