xref: /onnv-gate/usr/src/lib/libc/port/gen/gethz.c (revision 6812:febeba71273d)
10Sstevel@tonic-gate /*
20Sstevel@tonic-gate  * CDDL HEADER START
30Sstevel@tonic-gate  *
40Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*6812Sraf  * Common Development and Distribution License (the "License").
6*6812Sraf  * You may not use this file except in compliance with the License.
70Sstevel@tonic-gate  *
80Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
90Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
100Sstevel@tonic-gate  * See the License for the specific language governing permissions
110Sstevel@tonic-gate  * and limitations under the License.
120Sstevel@tonic-gate  *
130Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
140Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
150Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
160Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
170Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
180Sstevel@tonic-gate  *
190Sstevel@tonic-gate  * CDDL HEADER END
200Sstevel@tonic-gate  */
21*6812Sraf 
220Sstevel@tonic-gate /*
23*6812Sraf  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
240Sstevel@tonic-gate  * Use is subject to license terms.
250Sstevel@tonic-gate  */
260Sstevel@tonic-gate 
270Sstevel@tonic-gate /*	Copyright (c) 1988 AT&T	*/
280Sstevel@tonic-gate /*	  All Rights Reserved  	*/
290Sstevel@tonic-gate 
30*6812Sraf #pragma ident	"%Z%%M%	%I%	%E% SMI"
310Sstevel@tonic-gate 
32*6812Sraf #pragma weak _gethz = gethz
330Sstevel@tonic-gate 
34*6812Sraf #include "lint.h"
350Sstevel@tonic-gate #include <stdio.h>
360Sstevel@tonic-gate #include <ctype.h>
370Sstevel@tonic-gate #include <stdlib.h>
380Sstevel@tonic-gate 
390Sstevel@tonic-gate /*
400Sstevel@tonic-gate  *	gethz -- get the value of the clock hertz from the environment.
410Sstevel@tonic-gate  *
420Sstevel@tonic-gate  *	return the clock hertz value if the string "HZ" in the environment is:
430Sstevel@tonic-gate  *		1) Composed entirely of numbers.
440Sstevel@tonic-gate  *		2) Not equal to zero.
450Sstevel@tonic-gate  *	Otherwise 0 is returned.
460Sstevel@tonic-gate  */
470Sstevel@tonic-gate int
gethz(void)480Sstevel@tonic-gate gethz(void)
490Sstevel@tonic-gate {
500Sstevel@tonic-gate 	char *sptr, *cptr;
510Sstevel@tonic-gate 
520Sstevel@tonic-gate 	if ((sptr = getenv("HZ")) == NULL) {
530Sstevel@tonic-gate 		return (0);
540Sstevel@tonic-gate 	} else {
550Sstevel@tonic-gate 		cptr = sptr;
560Sstevel@tonic-gate 
570Sstevel@tonic-gate 		/* Check that all characters are numeric */
580Sstevel@tonic-gate 		while (*cptr) {
590Sstevel@tonic-gate 			if (!isdigit((unsigned char)*cptr))
600Sstevel@tonic-gate 				return (0);
610Sstevel@tonic-gate 			cptr++;
620Sstevel@tonic-gate 		}
630Sstevel@tonic-gate 		return (atoi(sptr));
640Sstevel@tonic-gate 	}
650Sstevel@tonic-gate }
66