atoi.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (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 (c) 1984 AT&T */
/* All Rights Reserved */
#pragma ident "%Z%%M% %I% %E% SMI" /* from S5R2 2.1 */
/*LINTLIBRARY*/
#include <ctype.h>
#define ATOI
#ifdef ATOI
typedef int TYPE;
#else
typedef long TYPE;
#endif
NAME(p)
register char *p;
{
register TYPE n;
register int c, neg = 0;
if (!isdigit(c = *p)) {
while (isspace(c))
c = *++p;
switch (c) {
case '-':
neg++;
case '+': /* fall-through */
c = *++p;
}
if (!isdigit(c))
return (0);
}
for (n = '0' - c; isdigit(c = *++p); ) {
n *= 10; /* two steps to avoid unnecessary overflow */
n += '0' - c; /* accum neg to avoid surprises at MAX */
}
return (neg ? n : -n);
}