xref: /titanic_51/usr/src/lib/libc/port/gen/atoi.c (revision 7257d1b4d25bfac0c802847390e98a464fd787ac)
17c478bd9Sstevel@tonic-gate /*
27c478bd9Sstevel@tonic-gate  * CDDL HEADER START
37c478bd9Sstevel@tonic-gate  *
47c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*7257d1b4Sraf  * Common Development and Distribution License (the "License").
6*7257d1b4Sraf  * You may not use this file except in compliance with the License.
77c478bd9Sstevel@tonic-gate  *
87c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
97c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
107c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
117c478bd9Sstevel@tonic-gate  * and limitations under the License.
127c478bd9Sstevel@tonic-gate  *
137c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
147c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
157c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
167c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
177c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
187c478bd9Sstevel@tonic-gate  *
197c478bd9Sstevel@tonic-gate  * CDDL HEADER END
207c478bd9Sstevel@tonic-gate  */
21*7257d1b4Sraf 
227c478bd9Sstevel@tonic-gate /*
23*7257d1b4Sraf  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
247c478bd9Sstevel@tonic-gate  * Use is subject to license terms.
257c478bd9Sstevel@tonic-gate  */
267c478bd9Sstevel@tonic-gate 
277c478bd9Sstevel@tonic-gate /*	Copyright (c) 1988 AT&T	*/
287c478bd9Sstevel@tonic-gate /*	  All Rights Reserved  	*/
297c478bd9Sstevel@tonic-gate 
30*7257d1b4Sraf #pragma ident	"%Z%%M%	%I%	%E% SMI"
317c478bd9Sstevel@tonic-gate 
32*7257d1b4Sraf #include "lint.h"
337c478bd9Sstevel@tonic-gate #include <ctype.h>
347c478bd9Sstevel@tonic-gate #include <sys/types.h>
357c478bd9Sstevel@tonic-gate #include <stdlib.h>
367c478bd9Sstevel@tonic-gate 
377c478bd9Sstevel@tonic-gate #define	ATOI
387c478bd9Sstevel@tonic-gate 
397c478bd9Sstevel@tonic-gate #ifdef	ATOI
407c478bd9Sstevel@tonic-gate typedef int TYPE;
417c478bd9Sstevel@tonic-gate #define	NAME	atoi
427c478bd9Sstevel@tonic-gate #else
437c478bd9Sstevel@tonic-gate typedef long TYPE;
447c478bd9Sstevel@tonic-gate #define	NAME	atol
457c478bd9Sstevel@tonic-gate #endif
467c478bd9Sstevel@tonic-gate 
477c478bd9Sstevel@tonic-gate TYPE
487c478bd9Sstevel@tonic-gate NAME(const char *p)
497c478bd9Sstevel@tonic-gate {
507c478bd9Sstevel@tonic-gate 	TYPE n;
517c478bd9Sstevel@tonic-gate 	int c, neg = 0;
527c478bd9Sstevel@tonic-gate 	unsigned char	*up = (unsigned char *)p;
537c478bd9Sstevel@tonic-gate 
547c478bd9Sstevel@tonic-gate 	if (!isdigit(c = *up)) {
557c478bd9Sstevel@tonic-gate 		while (isspace(c))
567c478bd9Sstevel@tonic-gate 			c = *++up;
577c478bd9Sstevel@tonic-gate 		switch (c) {
587c478bd9Sstevel@tonic-gate 		case '-':
597c478bd9Sstevel@tonic-gate 			neg++;
607c478bd9Sstevel@tonic-gate 			/* FALLTHROUGH */
617c478bd9Sstevel@tonic-gate 		case '+':
627c478bd9Sstevel@tonic-gate 			c = *++up;
637c478bd9Sstevel@tonic-gate 		}
647c478bd9Sstevel@tonic-gate 		if (!isdigit(c))
657c478bd9Sstevel@tonic-gate 			return (0);
667c478bd9Sstevel@tonic-gate 	}
677c478bd9Sstevel@tonic-gate 	for (n = '0' - c; isdigit(c = *++up); ) {
687c478bd9Sstevel@tonic-gate 		n *= 10; /* two steps to avoid unnecessary overflow */
697c478bd9Sstevel@tonic-gate 		n += '0' - c; /* accum neg to avoid surprises at MAX */
707c478bd9Sstevel@tonic-gate 	}
717c478bd9Sstevel@tonic-gate 	return (neg ? n : -n);
727c478bd9Sstevel@tonic-gate }
73