xref: /onnv-gate/usr/src/lib/libc/port/gen/gethz.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24*0Sstevel@tonic-gate  * Use is subject to license terms.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate /*	Copyright (c) 1988 AT&T	*/
30*0Sstevel@tonic-gate /*	  All Rights Reserved  	*/
31*0Sstevel@tonic-gate 
32*0Sstevel@tonic-gate 
33*0Sstevel@tonic-gate #pragma weak gethz = _gethz
34*0Sstevel@tonic-gate 
35*0Sstevel@tonic-gate #include "synonyms.h"
36*0Sstevel@tonic-gate #include <stdio.h>
37*0Sstevel@tonic-gate #include <ctype.h>
38*0Sstevel@tonic-gate #include <stdlib.h>
39*0Sstevel@tonic-gate 
40*0Sstevel@tonic-gate /*
41*0Sstevel@tonic-gate  *	gethz -- get the value of the clock hertz from the environment.
42*0Sstevel@tonic-gate  *
43*0Sstevel@tonic-gate  *	return the clock hertz value if the string "HZ" in the environment is:
44*0Sstevel@tonic-gate  *		1) Composed entirely of numbers.
45*0Sstevel@tonic-gate  *		2) Not equal to zero.
46*0Sstevel@tonic-gate  *	Otherwise 0 is returned.
47*0Sstevel@tonic-gate  */
48*0Sstevel@tonic-gate int
49*0Sstevel@tonic-gate gethz(void)
50*0Sstevel@tonic-gate {
51*0Sstevel@tonic-gate 	char *sptr, *cptr;
52*0Sstevel@tonic-gate 
53*0Sstevel@tonic-gate 	if ((sptr = getenv("HZ")) == NULL) {
54*0Sstevel@tonic-gate 		return (0);
55*0Sstevel@tonic-gate 	} else {
56*0Sstevel@tonic-gate 		cptr = sptr;
57*0Sstevel@tonic-gate 
58*0Sstevel@tonic-gate 		/* Check that all characters are numeric */
59*0Sstevel@tonic-gate 		while (*cptr) {
60*0Sstevel@tonic-gate 			if (!isdigit((unsigned char)*cptr))
61*0Sstevel@tonic-gate 				return (0);
62*0Sstevel@tonic-gate 			cptr++;
63*0Sstevel@tonic-gate 		}
64*0Sstevel@tonic-gate 		return (atoi(sptr));
65*0Sstevel@tonic-gate 	}
66*0Sstevel@tonic-gate }
67