1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /* Copyright (c) 1988 AT&T */
28 /* All Rights Reserved */
29
30 #pragma ident "%Z%%M% %I% %E% SMI"
31
32 #pragma weak _gethz = gethz
33
34 #include "lint.h"
35 #include <stdio.h>
36 #include <ctype.h>
37 #include <stdlib.h>
38
39 /*
40 * gethz -- get the value of the clock hertz from the environment.
41 *
42 * return the clock hertz value if the string "HZ" in the environment is:
43 * 1) Composed entirely of numbers.
44 * 2) Not equal to zero.
45 * Otherwise 0 is returned.
46 */
47 int
gethz(void)48 gethz(void)
49 {
50 char *sptr, *cptr;
51
52 if ((sptr = getenv("HZ")) == NULL) {
53 return (0);
54 } else {
55 cptr = sptr;
56
57 /* Check that all characters are numeric */
58 while (*cptr) {
59 if (!isdigit((unsigned char)*cptr))
60 return (0);
61 cptr++;
62 }
63 return (atoi(sptr));
64 }
65 }
66