xref: /freebsd/libexec/atrun/gloadavg.c (revision a7623790fb345e6dc986dfd31df0ace115e6f2e4)
1 /*-
2  *  gloadavg.c - get load average for Linux
3  *  Copyright (C) 1993  Thomas Koenig
4  *
5  * SPDX-License-Identifier: BSD-2-Clause
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. The name of the author(s) may not be used to endorse or promote
13  *    products derived from this software without specific prior written
14  *    permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #ifndef lint
29 static const char rcsid[] =
30   "$FreeBSD$";
31 #endif /* not lint */
32 
33 #ifndef __FreeBSD__
34 #define _POSIX_SOURCE 1
35 
36 /* System Headers */
37 
38 #include <stdio.h>
39 #else
40 #include <stdlib.h>
41 #endif
42 
43 /* Local headers */
44 
45 #include "gloadavg.h"
46 
47 /* Global functions */
48 
49 void perr(const char *fmt, ...);
50 
51 double
52 gloadavg(void)
53 /* return the current load average as a floating point number, or <0 for
54  * error
55  */
56 {
57     double result;
58 #ifndef __FreeBSD__
59     FILE *fp;
60 
61     if((fp=fopen(PROC_DIR "loadavg","r")) == NULL)
62 	result = -1.0;
63     else
64     {
65 	if(fscanf(fp,"%lf",&result) != 1)
66 	    result = -1.0;
67 	fclose(fp);
68     }
69 #else
70     if (getloadavg(&result, 1) != 1)
71 	    perr("error in getloadavg");
72 #endif
73     return result;
74 }
75