libexec/atrun/gloadavg.c

   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  * $FreeBSD: src/libexec/atrun/gloadavg.c,v 1.5 1999/08/28 00:09:12 peter Exp $
  26  * $DragonFly: src/libexec/atrun/gloadavg.c,v 1.3 2004/02/03 23:24:50 rob Exp $
  27  */
  28
  29 #ifndef __DragonFly__
  30 #define _POSIX_SOURCE 1
  31
  32 /* System Headers */
  33
  34 #include <stdio.h>
  35 #else
  36 #include <stdlib.h>
  37 #endif
  38
  39 /* Local headers */
  40
  41 #include "gloadavg.h"
  42
  43 /* Global functions */
  44
  45 void perr(const char *a);
  46
  47 double
  48 gloadavg(void)
  49 /* return the current load average as a floating point number, or <0 for
  50  * error
  51  */
  52 {
  53     double result;
  54 #ifndef __DragonFly__
  55     FILE *fp;
  56
  57     if((fp=fopen(PROC_DIR "loadavg","r")) == NULL)
  58         result = -1.0;
  59     else
  60     {
  61         if(fscanf(fp,"%lf",&result) != 1)
  62             result = -1.0;
  63         fclose(fp);
  64     }
  65 #else
  66     if (getloadavg(&result, 1) != 1)
  67             perr("error in getloadavg");
  68 #endif
  69     return result;
  70 }