xref: /freebsd/libexec/atrun/gloadavg.c (revision f0adf7f5cdd241db2f2c817683191a6ef64a4e95)
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
27 static const char rcsid[] =
28   "$FreeBSD$";
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 
47 void perr(const char *a);
48 
49 double
50 gloadavg(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