Tag Archives: Mac OS X

WhatsApp Web is keeping my Mac awake

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The new WhatsApp Web client is a welcome companion to the hugely popular WhatsApp Messenger cross-platform mobile application. It allows users to link their browser to their WhatsApp account and interact with chat sessions just like you do in the mobile app.

So far so good, but I have encountered one significant drawback. If you run the web client in a Google Chrome session on Mac OS X then a kernel assertion is established which prevents the system from sleeping, regardless of energy saver system preferences.

With the WhatsApp Web client running:

$ /usr/bin/pmset -g assertions
2015-01-29 17:47:11 +0000 
Assertion status system-wide:
 BackgroundTask 0
 ApplePushServiceTask 0
 UserIsActive 0
 PreventUserIdleDisplaySleep 0
 PreventSystemSleep 0
 ExternalMedia 0
 PreventUserIdleSystemSleep 1
 NetworkClientActive 0
Listed by owning process:
 pid 346(coreaudiod): [0x0006336d00011046] 00:00:50 PreventUserIdleSystemSleep named: "com.apple.audio.context532.preventuseridlesleep" 
 Created for PID: 12006.

With the WhatsApp Web session closed:

$ /usr/bin/pmset -g assertions
2015-01-29 17:47:23 +0000 
Assertion status system-wide:
 BackgroundTask 0
 ApplePushServiceTask 0
 UserIsActive 0
 PreventUserIdleDisplaySleep 0
 PreventSystemSleep 0
 ExternalMedia 0
 PreventUserIdleSystemSleep 0
 NetworkClientActive 0

I assume that this sleep issue is related to the notification feature of WhatsApp Web, since the assertion references Mac OS X’s coreaudiod process. Turning off desktop alerts and sounds in the client settings does not fix it however, so for the moment it doesn’t seem possible to prevent this system insomnia from occurring.

I shall contact WhatsApp product support and see what they can do.

Printing to a Samsung ML-1210 on Mac OS X

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Although Samsung stopped providing official Mac OS drivers for the ML-1210 laser printer long ago, it is still possible to use this venerable old laser printer with the latest Mac OS X.

First download the latest Open Source Samsung-GDI for Mac OS X and GPL Ghostscript for Mac OS X packages from The Linux Foundation.

Next you’ll need the Foomatic-RIP package, but don’t download the latest version!

You need to use Foomatic-RIP version 3.0.2 (dated 30th January 2008), otherwise your print-outs will include a top margin which you can’t remove. Fortunately the older working version is still available from OpenPrinting.org.

Open each downloaded disk image in turn and run the installers. When all three packages have been installed you are ready to add the printer.

Connect your printer using an appropriate USB cable. Now go to Mac OS X System Preferences and select ‘Print & Scan’. Click on the ‘+’ button and a new ‘Add Printer’ window will open.

Assuming your printer is connected you should see ‘Samsung ML-1210’ already in the printer window. Click on that printer name and then open the drop-down list of printer drivers next to “Print Using”. Select ‘Samsung ML-1210 Foomatic/GDI’ and then the ‘Add’ button.

Your printer has been added. Legacy printer revival achievement unlocked!

Dropbox & EncFS on OS X Lion

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I previously wrote about a method for creating a super-secure filesystem using Dropbox’s cloud storage.

After updating to Mac OS Lion I struggled to get the MacFusion GUI to work and so I wrote an application to automate the mounting and unmounting of the EncFS filesystem.

I also took the opportunity to switch from the now abandoned MacFUSE to Fuse4X, which is a properly maintained fork of MacFUSE started in June 2011.

The install procedure is much simpler than before, you install Fuse4X and EncFS, but instead of using the MacFusion GUI you just call my script instead.

To the instructions!

First download and install Fuse4X and a version of EncFS which uses the Fuse4X APIs. Thanks to Simone Lehmann for providing an EncFS Mac installer at http://www.lisanet.de/?p=128 (also mirrored here).

To create a new encrypted volume (stored locally at first to prevent the EncFS key from being synchronised with Dropbox):

encfs ~/Desktop/_Encrypted ~/Documents/_DropSec

Answer ‘yes’ when prompted to create the new folders and choose ‘p’ for pre-configured paranoia mode (256-bit AES encryption). Enter a secure EncFS password when prompted and you’re done.

Now the filesystem has been created we can deal with securing the key.

umount ~/Documents/_DropSec
mkdir ~/.keys
mv ~/Desktop/_Encrypted/.encfs6.xml ~/.keys/dropsec.xml

The commands above move your key from the EncFS filesystem into a hidden folder in your (local) home directory

Now move the entire ~/Desktop/_Encrypted folder (minus your key) into your Dropbox:

mv ~/Desktop/_Encrypted ~/Dropbox/

Finally download my DropSec application and copy it to your Applications folder.

The first time you run DropSec it will prompt you for your EncFS password which it stores in your local login keychain. The password must match the secure password you set in a previous step.

To mount or unmount the encrypted filesystem simply run the DropSec app. For convenience copy it to your Mac OS Dock for quick access.