system_cmds/atrun.tproj/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
  26 #ifndef lint
  27 static const char rcsid[] =
  28   "$FreeBSD: src/libexec/atrun/gloadavg.c,v 1.5 1999/08/28 00:09:12 peter Exp $";
  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 }