Avenrun in IRIX 3.2

[Patrick Wolfe]

> Written by srp at babar.mmwb.ucsf.edu
>	Avenrun seems to be available in the IRIX 3.2 kernel as an array of
> longs.  But as in the Sun kernel it appears to need a scaling... 1024 seems
> about right.  Does anyone know what and/or where the appropriate constant
> might be found?

FSCALE is sometimes defined in <sys/param.h>, and on some machines it's
missing.  It's usually either 1 or 1000.  Here's a program that displays the
hostname and three load average numbers successfully on SGI Irix 3.2, Sequent
Dynix V3.0, Alliant Concentrix V5.0, Concurrent RTU V5.0, and (I think) SunOS
3.0.  The original load average code is from the screen program.  You need
read permissions on /dev/kmem to make it work.

#! /bin/sh
# This is a shell archive.  Remove anything before this line, then unpack
# it by saving it into a file and typing "sh file".  To overwrite existing
# files, type "sh file -c".  You can also feed this as standard input via
# unshar, or by typing "sh <file", e.g..  If this archive is complete, you
# will see the following message at the end:
#		"End of shell archive."
# Contents:  loadavg.c Makefile
# Wrapped by pwolfe at kailand on Thu Nov 30 13:07:36 1989
PATH=/bin:/usr/bin:/usr/ucb ; export PATH
if test -f 'loadavg.c' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'loadavg.c'\"
else
echo shar: Extracting \"'loadavg.c'\" \(2516 characters\)
sed "s/^X//" >'loadavg.c' <<'END_OF_FILE'
X/*
X *	loadavg.c - display system load average
X *
X *	Original load average code from the screen V2 program by Oliver Lauman.
X */
X
X#include <stdio.h>
X#include <nlist.h>
X#include <sys/types.h>
X#include <sys/file.h>
X
X#if defined(sun) || defined(sequent) || defined(sgi)
X#define SUNLOADAV
X#endif
X
X#ifdef SUNLOADAV
X#include <sys/param.h>
X#endif
X
X#undef FSCALE
X#ifdef SUNLOADAV
X#define FSCALE 1000.0
X#else
X#define FSCALE 1.0
X#endif
X
X#define KMEMNAME "/dev/kmem"
X
X#ifdef sequent
X#define KERNELPATH "/dynix"
X#else
X#if defined(masscomp) || defined(sgi)
X#define KERNELPATH "/unix"
X#else
X#define KERNELPATH "/vmunix"
X#endif /* masscomp or sgi */
X#endif /* sequent */
X
X#ifdef alliant
X#define LOADAVGSYMBOL "_Loadavg"
X#else
X#ifdef sgi
X#define LOADAVGSYMBOL "avenrun"
X#else
X#define LOADAVGSYMBOL "_avenrun"
X#endif /* sgi */
X#endif /* alliant */
X
X#ifdef SUNLOADAV
X#define LOADAVGTYPE long
X#else
X#ifdef alliant
X#define LOADAVGTYPE long
X#else
X#ifdef masscomp
X#define LOADAVGTYPE float
X#else
X#define LOADAVGTYPE double
X#endif /* masscomp */
X#endif /* alliant */
X#endif /* SUNLOADAV */
X
Xstatic struct nlist nl[2];
X#	Alliant actually has FOUR numbers available, the last one
X#	being the load average over the past 60 minutes.
X#	We'll ignore that for portability
Xstatic LOADAVGTYPE loadav[3];
Xstatic int kmemf;
Xstatic char KmemName[] = KMEMNAME;
Xstatic char UnixName[] = KERNELPATH;
Xstatic char AvenrunSym[] = LOADAVGSYMBOL;
Xstatic char hostname[64];
X
Xmain () {
X
X	/*
X	 *	get name of this host
X	 */
X	if (gethostname (hostname, 64) == -1) {
X		perror ("gethostname failed");
X		exit (1);
X		}
X
X	/*
X	 *	open kernel memory
X	 *	may require special priviledges
X	 */
X	if ((kmemf = open (KmemName, O_RDONLY)) == -1) {
X		perror ("open of /dev/kmem failed:");
X		exit (1);
X		}
X
X	/*
X	 *	locate load average numbers
X	 */
X	nl[0].n_name = AvenrunSym;
X	nlist (UnixName, nl);
X	if (nl[0].n_type == 0 || nl[0].n_value == 0) {
X		perror ("nlist of Unix kernel failed:");
X		exit (1);
X		}
X
X	/*
X	 *	seek into kmem
X	 */
X#ifdef sgi
X	if (lseek (kmemf, nl[0].n_value & ~0x80000000, 0) == -1) {
X#else
X	if (lseek (kmemf, nl[0].n_value, 0) == -1) {
X#endif
X		perror ("lseek into /dev/kmem failed");
X		exit (1);
X		}
X
X	/*
X	 *	read numbers from memory
X	 */
X	if (read (kmemf, loadav, sizeof (loadav)) != sizeof (loadav)) {
X		perror ("read from /dev/kmem failed");
X		exit (1);
X		}
X
X	/*
X	 *	display the numbers
X	 */
X
X	printf ("%s %04.2f %04.2f %04.2f\n", hostname, (LOADAVGTYPE)loadav[0]/FSCALE,
X	    (LOADAVGTYPE)loadav[1]/FSCALE, (LOADAVGTYPE)loadav[2]/FSCALE);
X
X	exit (0);
X	}
END_OF_FILE
if test 2516 -ne `wc -c <'loadavg.c'`; then
    echo shar: \"'loadavg.c'\" unpacked with wrong size!
fi
# end of 'loadavg.c'
fi
if test -f 'Makefile' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'Makefile'\"
else
echo shar: Extracting \"'Makefile'\" \(377 characters\)
sed "s/^X//" >'Makefile' <<'END_OF_FILE'
X#	uncommment for SGI
X#LIBS     = -lmld
X
XCFLAGS   = -g $(INCLUDES) $(DEFINES)
XBIN      = /usr/local/bin
XKMEMGRP  = kmem
XSHELL    = /bin/sh
X 
Xloadavg: loadavg.c
X	$(CC) $(CFLAGS) -o loadavg loadavg.c $(LIBS)
X
Xinstall: loadavg
X	rm -f $(BIN)/loadavg
X	cp loadavg $(BIN)/loadavg
X	-chgrp $(KMEMGRP) $(BIN)/loadavg
X	chmod 2711 $(BIN)/loadavg
X
Xclean:
X	rm -f a.out core mklog loadavg *.o
END_OF_FILE
if test 377 -ne `wc -c <'Makefile'`; then
    echo shar: \"'Makefile'\" unpacked with wrong size!
fi
# end of 'Makefile'
fi
echo shar: End of shell archive.
exit 0