gloadavg.c revision 50476 
1/*
2 *  gloadavg.c - get load average for Linux
3 *  Copyright (C) 1993  Thomas Koenig
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. The name of the author(s) may not be used to endorse or promote
11 *    products derived from this software without specific prior written
12 *    permission.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef lint
27static const char rcsid[] =
28  "$FreeBSD: head/libexec/atrun/gloadavg.c 50476 1999-08-28 00:22:10Z peter $";
29#endif /* not lint */
30
31#ifndef __FreeBSD__
32#define _POSIX_SOURCE 1
33
34/* System Headers */
35
36#include <stdio.h>
37#else
38#include <stdlib.h>
39#endif
40
41/* Local headers */
42
43#include "gloadavg.h"
44
45/* Global functions */
46
47void perr(const char *a);
48
49double
50gloadavg(void)
51/* return the current load average as a floating point number, or <0 for
52 * error
53 */
54{
55    double result;
56#ifndef __FreeBSD__
57    FILE *fp;
58
59    if((fp=fopen(PROC_DIR "loadavg","r")) == NULL)
60	result = -1.0;
61    else
62    {
63	if(fscanf(fp,"%lf",&result) != 1)
64	    result = -1.0;
65	fclose(fp);
66    }
67#else
68    if (getloadavg(&result, 1) != 1)
69	    perr("error in getloadavg");
70#endif
71    return result;
72}
73