atoi.c revision 7257d1b4d25bfac0c802847390e98a464fd787ac
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1988 AT&T */
/* All Rights Reserved */
#pragma ident "%Z%%M% %I% %E% SMI"
#include "lint.h"
#include <ctype.h>
#include <stdlib.h>
#define ATOI
#ifdef ATOI
typedef int TYPE;
#else
typedef long TYPE;
#endif
NAME(const char *p)
{
TYPE n;
int c, neg = 0;
unsigned char *up = (unsigned char *)p;
while (isspace(c))
c = *++up;
switch (c) {
case '-':
neg++;
/* FALLTHROUGH */
case '+':
c = *++up;
}
if (!isdigit(c))
return (0);
}
n *= 10; /* two steps to avoid unnecessary overflow */
n += '0' - c; /* accum neg to avoid surprises at MAX */
}
return (neg ? n : -n);
}