ENV['COMPUTERNAME'] for Mac?

honkinberry

Hi all,
long-time fan, first time posting.

I was hoping to access ENV['COMPUTERNAME'] to use with our License management system.
But it seems that value is only available on the PC side. Is there a way to get this on the Mac side?

Thanks for any assistance!

--J

Jim

Does Mac have an /etc/hostname file?

Aerilius

You can't rely on the existence of environment variables (they are not cross-platform like the SketchUp API and even differ between operating system versions). Take them rather as "hints".

Did you already look through all results of this?
ENV.each{|k,v| puts " #{k}: #{v}" }; nil

In case it's not in ENV, I guess OS X has an app for that: uname -n``
(Just a guess, I don't use that.)

honkinberry

There is indeed an etc/hostname file, and that's what I want -- how to read that from SU Ruby?

And as for iterating ENV, isn't it a bit quicker to just type ENV ? That seems to work.

--J

Dan Rathbun

@honkinberry said:

And as for iterating ENV, isn't it a bit quicker to just type ENV ? That seems to work.

Problem is that setting a bogus environment variable, or setting a valid variable to a bogus temporary setting, is quite easy; .. both with a shell script, and from within Ruby.

I would suggest looking into some sort of encrypted key.. what about SSH ?

honkinberry

I'm not so concerned if a user has set the ENV variable to a bogus value in an attempt to circumvent our licensing system. I was hoping for just a 95% solution.
(Key point, why would someone hack a license system for free software???)

So I just want to query the machine name on a Mac, secure or not.
If there's a way to do that with SSH, if you could point in the right direction, I'll find out.

Dan Rathbun

@honkinberry said:

(Key point, why would someone hack a license system for free software???)

Your OP said nothing about it being free.

I would counter, why would you want to complicate free software with a license management system ?

Why would users want the hassle ?

Aerilius

So why don't you query it simply with uname -n``? No ssh needed (?).

driven

from Ruby Console

`ioreg -rd1 -c IOPlatformExpertDevice | awk '/IOPlatformUUID/ { printf; }' `

returns
"IOPlatformUUID" = "00000000-0000-1000-8000-001E••••••••"
I believe this is reasonably robust and unique...
the ••••• are just me masking mine.
john

edit to add from the man page...

DESCRIPTION
ioreg displays the I/O Kit registry. It shows the heirarchical registry
structure as an inverted tree. The provider-client relationships among
those objects is shown as follows:

 +-o provider
   |
   +-o client

 By default, object properties are not shown.  The use of the -c, -k, -l,
 or -n options cause ioreg to show properties for objects that match the
 specified criteria.

Jim

@honkinberry said:

There is indeed an etc/hostname file, and that's what I want -- how to read that from SU Ruby?

--J

Just read it.

hostname = File.read('/etc/hostname').strip

driven

@jim said:

Does Mac have an /etc/hostname file?

only if someone/or some code has added it already...
Error: #<Errno::ENOENT: (eval):2:inread': No such file or directory - /etc/hostname>`
in /etc/ I have
hostconfig
hosts
hosts.equiv
but none contain any 'unique-ness' identifiers.
john

honkinberry

driven is correct, no such filename.
I was incorrect, I did a "cd /etc" and then typed "hostname", like an idiot. Sorry.

the ioreg is interesting, but when I try that from Ruby console I get undefined local variable or method.

I appreciate everybody's help.
To emphasize, I was looking for something quick and easy, along the lines of the ENV vars.
If SU doesn't have that on the Mac side, I can add a config.rb faster than any other solution.
It sure would be nice to have, hint hint!!!

--J

driven

@honkinberry said:

the ioreg is interesting, but when I try that from Ruby console I get undefined local variable or method.

try without the awk filtering

theLot=(`ioreg -rd1 -c IOPlatformExpertDevice 2>&1` )

should give a proper error if not the return...

then sort from the return what you want...
{ "compatible" = <"iMac7,1"> "version" = <"1.0"> "board-id" = <"Mac-F42386C8"> "IOInterruptSpecifiers" = (*********************long number hidden by me*************************) "IOPolledInterface" = "SMCPolledInterface is not serializable" "serial-number" = <*********************long number hidden by me*************************> "IOInterruptControllers" = ("io-apic-0") "IOPlatformUUID" = "*********************long number hidden by me*************************" "IOPlatformArgs" = <*********************long number hidden by me*************************> "clock-frequency" = <0008af2f> "manufacturer" = <"Apple Inc."> "IOConsoleSecurityInterest" = "IOCommand is not serializable" "IOPlatformSerialNumber" = "W8****ditto****T" "system-type" = <01> "product-name" = <"iMac7,1"> "model" = <"iMac7,1"> "name" = <"/"> "IOBusyInterest" = "IOCommand is not serializable" }
remember, not all macs have a serial number
john

Jim

@honkinberry said:

I was incorrect, I did a "cd /etc" and then typed "hostname", like an idiot. Sorry.

You can use that then.

hostname =hostname.stip

(Works on win 8, but not sure how far back in terms of windows versions the command exists.)

I just assumed unique-ness was not an issue otherwise it would have been part of the original request.

host names and computer names are definitely not unique.

honkinberry

Oh, both of these last pasts, bammo, thank you guys!!!!
the ioreg is interesting for sure -- the board-id seems valuable for my purposes.

But Jim is correct!
hostname does indeed work.
So for me at least, it's as easy as:
machinename = ENV['COMPUTERNAME']
if (!machinename) then machinename = hostname # must be a Mac

Thanks all!!!

driven

@honkinberry said:

Jim is correct!
hostname does indeed work.

but that returns the same on all 5 macs on my network, so for a Licence management usage it seems a bit pointless?
If you only need to know if it's a mac or not there are many simple ways to get that...

glad your happy

john