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 weak _gethz = gethz
31
32 #include "lint.h"
33 #include <stdio.h>
34 #include <ctype.h>
35 #include <stdlib.h>
36
37 /*
38 * gethz -- get the value of the clock hertz from the environment.
39 *
40 * return the clock hertz value if the string "HZ" in the environment is:
41 * 1) Composed entirely of numbers.
42 * 2) Not equal to zero.
43 * Otherwise 0 is returned.
44 */
45 int
gethz(void)46 gethz(void)
47 {
48 char *sptr, *cptr;
49
50 if ((sptr = getenv("HZ")) == NULL) {
51 return (0);
52 } else {
53 cptr = sptr;
54
55 /* Check that all characters are numeric */
56 while (*cptr) {
57 if (!isdigit((unsigned char)*cptr))
58 return (0);
59 cptr++;
60 }
61 return (atoi(sptr));
62 }
63 }
64