Mac Geekery

Macs have quite a few hardware and temperature sensors, but the only CLI option I’d run across is the tool that comes with Temperature Monitor.app, which is a binary. I was thinking that you’d have to use some sort of frameworks and compiled Obj-C to access these readouts, but while mucking around in the guts of my machine trying to write a system monitoring script, I noticed that the information is available deep within ioreg, apparently undocumented and slightly hidden (all the numbers are multiplied by 65536).

Update: See comments, this may not be that accurate at all.

So I was able to write a script that displays all the hardware sensor readouts of my machine. It turns out that all the different macs have different sensors and the formatting in ioreg can also vary, but after getting some dumps from friends with different macs, and visiting an Apple Store and looking in the guts of a few of them, I was able to make a script that should return all the hardware sensor values (if any — the mac mini seems to have none) of any recent mac, without having to write a special case for each one.

The formatting of the display may be a little wierd (then again it may not be) but this is so it will work even on dual G5s, which have an absurd amount of obscure sensors, and are not available for me to test on.

Also, the script can be pretty easily scripted itself to make the display prettier, and I am willing to fix up displays for individual machines if you send me what the readout looks like . Please, anyone that tests this leave a comment or email telling me how it works and what machine you are running and improve this thing.

But yeah, maybe I just haven’t seen where this has been done before, but I think it’s pretty sweet to be able to get these readouts through bash.

Here’s the script. Save it, chmod +x, throw it in your PATH, and use “tp -h” for usage instructions.

#!/bin/bash
#
	

		
TP Probe v.0.1
	
#

	

		
Gets stats from hardware sensors, such as temperatures, voltages,
		
and fanspeeds. For Mac OS X. Sensors vary depending on machine,
		
Powermacs have lots, down to mac mini’s, which don’t seem to have
		
any. Formatting may be rough, because there is wide variation
		
between machines, and I wanted to capture all possible sensors on
		
as many macs as possible and I only own one.
	
#

	

		
If you run this and it works, or doesn’t work, or looks awful, or
		
anything, please send me an email, preferably including the output
		
of tp -l so I can make this better.
	
#

	

		
————————————————————————————————-
		
This program is free software; you can redistribute it and/or
		
modify it under the terms of the GNU General Public License
		
as published by the Free Software Foundation; either version 2
		
of the License, or (at your option) any later version.
		

		
This program 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 General Public License for more details.
		
http://www.gnu.org/licenses/gpl.html
	
#

	

		
Copyright © 2005 Rupa Deadwyler djbidi@gmail.com
	


	

		
test operating sytem
	

	
if [ `uname` == “Darwin” ]
 then

	

		
help message
	

 if [ “$1” == “-h” ]
  then 
  basename=`echo $0 | sed ‘s/.*\///’`
  echo “usage: $basename [option]”
  echo “     -l also show Machine Name and CPU Type”
  echo “     -h display this help message”
  echo “     -e  diplay only lines that match regex”
  exit
 fi

	

		
if -l display Machine Name and CPU Type
	

 if [ “$1” == “-l” ]
  then
  system_profiler SPHardwareDataType | awk ‘/Machine Name/ || /Machine Model/ || /CPU Type/’ | sed ‘s/[^:]*: //’ | awk ‘{ printf $0 “  “ }’
  echo
 fi

	

		
sensor data

sensors=`ioreg -n IOHWSensor | awk ‘/location/ || /current-value/ || /“type”/’ | sed -e ‘s/[^”]*”//’ -e ‘s/” =//’ -e ‘s/location//’ -e ‘s/type//’ -e ‘s/”//g’ | awk ‘{ d=($2/65536); if ($1==“current-value”) print substr(d,1,7) “\t” ; if ($1!=“current-value”) print $0 }’ | sed -e ‘s/temperature/Celsius/’ -e ‘s/voltage/volts/’ -e ‘s/fanspeed/fan RPM/’ -e ‘s/current/Amps/’ -e ‘s/^temp$//’ -e ‘s/ //’ | awk ‘{ if ((NR % 3) == 0) print $0; else printf $0 “ “ }’`
	

	

		

	

	
if [ “$1”  "-e" ]
 then
 if [ "$2"  “” ]
  then
  echo no regex selected
 else
  echo “$sensors” | awk “/$2/”
 fi

else
 echo “$sensors”

fi

	

		
error message if unsupported machine
	

	
else
 echo -e “\nThis appears not to be an OS X machine\n”

fi

The script is also available here: cutup.org/code/sh