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/* Get system load averages. Linux (/proc/loadavg) version.
Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
/* Put the 1 minute, 5 minute and 15 minute load averages
into the first NELEM elements of LOADAVG.
Return the number written (never more than 3, but may be less than NELEM),
or -1 if an error occurred. */
int
getloadavg (double loadavg[], int nelem)
{
int fd;
fd = __open ("/proc/loadavg", O_RDONLY);
if (fd < 0)
return -1;
else
{
char buf[65], *p;
ssize_t nread;
int i;
nread = __read (fd, buf, sizeof buf - 1);
__close (fd);
if (nread < 0)
return -1;
buf[nread - 1] = '\0';
if (nelem > 3)
nelem = 3;
p = buf;
for (i = 0; i < nelem; ++i)
{
char *endp;
loadavg[i] = strtod (p, &endp);
if (!endp || endp == p)
/* This should not happen. The format of /proc/loadavg
must have changed. Don't return with what we have,
signal an error. */
return -1;
p = endp;
}
return i;
}
}
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