68 lines
1.9 KiB
C
68 lines
1.9 KiB
C
/* Get system load averages. Linux (/proc/loadavg) version.
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Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <errno.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <stdlib.h>
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/* Put the 1 minute, 5 minute and 15 minute load averages
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into the first NELEM elements of LOADAVG.
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Return the number written (never more than 3, but may be less than NELEM),
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or -1 if an error occurred. */
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int
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getloadavg (double loadavg[], int nelem)
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{
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int fd;
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fd = __open ("/proc/loadavg", O_RDONLY);
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if (fd < 0)
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return -1;
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else
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{
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char buf[65], *p;
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ssize_t nread;
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int i;
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nread = __read (fd, buf, sizeof buf - 1);
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__close (fd);
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if (nread < 0)
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return -1;
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buf[nread - 1] = '\0';
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if (nelem > 3)
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nelem = 3;
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p = buf;
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for (i = 0; i < nelem; ++i)
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{
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char *endp;
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loadavg[i] = strtod (p, &endp);
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if (!endp || endp == p)
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/* This should not happen. The format of /proc/loadavg
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must have changed. Don't return with what we have,
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signal an error. */
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return -1;
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p = endp;
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}
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return i;
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}
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}
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