WTF!, when did those files get deleted ?!

A guy I work with recently showed me a bad situation he had with iPhoto, some family videos had gone missing from his harddisk. The thumbnails were in iPhoto, but when he clicked on them, they wouldn't play because the files were gone. He had Time Machine backups, but they were gone even in the oldest copies. Apparently the files had been deleted quite a while ago.

This got me thinking about a huge problem with backups - you can be very diligent about keeping them, but if you have no idea that something's missing they don't do you much good.

What you need is something that would alert you of unexpected deletions. Thinking about my friend's experience, I whipped together a small shell script that would be run periodically to take an inventory of the iPhoto originals, and if something was removed compared to the last run, it would place a file on my desktop that hopefully I'd notice, listing a diff of the changes.

I saved this on my disk as /Users/barryp/bin/

# Check if anything has been deleted from the iPhoto Originals
# folder, and if so, place a file on the Desktop listing what's
# gone missing


find ~/Pictures/iPhoto\ Library/Originals -type f | sort >$
if [ -e $CHECK_FILE ]
    diff -u $CHECK_FILE $ >$CHECK_FILE.diff
    grep '^-/' $CHECK_FILE.diff >$CHECK_FILE.gone
    if [ -s $CHECK_FILE.gone ]
        mv $CHECK_FILE.diff "$HOME/Desktop/DELETED iPhoto files-`date "+%Y-%m-%d %H%M%S"`.txt"
        rm $CHECK_FILE.diff
    rm $CHECK_FILE.gone

and made it executable with

chmod +x /Users/barryp/bin/

Other than the directory name to check, there's nothing iPhoto or even Mac specific about this, it could be easily adapted for other uses.

You can run the script manually too anytime you want, and you can test this out by running once, editing ~/Library/Logs/com.diskcompare.inventory_iphoto.txt to add a line (starting with a /), and then running the script again to make sure a diff file pops up on your desktop showing how the line you manually added is gone in the updated inventory.

Next, I setup the Mac to run this once a day or so, by creating a launchd job saved as /Users/barryp/Library/LaunchAgents/com.diskcompare.inventory_iphoto.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "">
<plist version="1.0">

(You'll have to change the path to the script to suit your setup, unfortunately it doesn't seem you can use tilde expansion in a launchd job)

and then activated it in launchd with this command at the command prompt:

launchctl load ~/Library/LaunchAgents/com.diskcompare.inventory_iphoto.plist

Fortunately my friend found a really old harddisk that happened to have his missing videos on it, but he's even more lucky to have noticed the problem in the first place.

With a periodic inventory as described above, hopefully a person would become aware of a problem with in a day or two, in plenty of time get the files out of a backup system.

Flash playback on MacOSX Firefox

For a long time I've been annoyed by really jerky playback on Flash videos under Firefox on MacOSX.
This YouTube video for example, was just awful to watch, stuttering very frequently.

Turns out the fix is pretty simple: just go into about:config and increase the browser.sessionstore.interval setting in Firefox from the default of 10000 (10 seconds) to something larger like 120000 (120 seconds).
Got it from this page, even though it's talking about Ubuntu Firefox, it still applies to MacOSX and seems to have made a world of difference.

Building additional PHP modules on OSX

Normally I try to avoid dealing with PHP if at all possible, but there is now a PHP port of py-amqplib called php-amqplib, and I offered to help out with it a bit. Maybe partially out of guilt for having written the mess of Python code it was based on :)

I thought it would be handy to work on it using my MacBook. OS X 10.5 (Leopard) has PHP 5.2.6 built in standard, but unfortunately it doesn't have the bcmath extension included, which php-amqplib makes use of. Turns out building the module wasn't that difficult. This page got me going - although building bcmath was much simpler. Since I had the Apple Developer Tools for 10.5 installed, it was just a matter of ...

And then edit /etc/php.ini to make these two changes:

--- php.ini.default 2008-07-15 14:19:15.000000000 -0500 +++ php.ini 2008-12-08 21:44:52.000000000 -0600 @@ -483,7 +483,7 @@ user_dir = ; Directory in which the loadable extensions (modules) reside. -extension_dir = "./" +;extension_dir = "./" ; Whether or not to enable the dl() function. The dl() function does NOT work ; properly in multithreaded servers, such as IIS or Zeus, and is automatically @@ -595,6 +595,7 @@ ; needs to go here. Specify the location of the extension with the ; extension_dir directive above. ; Windows Extensions ; Note that ODBC support is built in, so no dll is needed for it.

After that, I was able to run the amqp_test.php file for the first time, sending a message and receiving it in py-amqplib's demo/

Macbook sleep problem

I've been using a Macbook for a couple years now, and really love the thing - but it's had an annoying sleep disorder that I finally found a workaround for.

I rarely shut it off, usually just closing the lid when I'm not using it, so it goes to sleep. The problem has been waking up back up - often I'd open the lid and start to enter the password to unlock the system, and the screen would go black and the machine would act sort of half-asleep. It almost seemed like it was confused as to whether the lid was open or not - maybe it was something with the lid sensor (which some other discussions online hinted at).

It turns out there's a command-line utility to change some power settings, and using it to set the machine not to wake up when the lid opens seems to help. The command is:

sudo pmset -a lidwake 0

The machine still goes to sleep when the lid closes, but now after opening the lid it waits until I hit a key on the keyboard before it rouses itself. After 3 or 4 days of this, it hasn't acted up yet, so I think this is a good fix.

Logitech QuickCam Communicate STX

Earlier, I wrote about setting up a Mac Mini user running OSX Tiger 10.4.x with a Logitech QuickCam Pro 5000, and how there was trouble using the camera's microphone. Fixing it involved mucking around with Mac OSX kernel extensions, and later automatic updates seem to have messed that up.

Rather than keep fighting with OSX, I swapped out that webcam for a Logitech QuickCam Communicate STX. Specifically, the model with part # 961464-0403.

It's not supported by default with OSX 10.4.x, but it is supported by macam, which is ridiculously easy to install. After doing so it worked fine with Skype, and the auto-exposure feature even worked, where it adjusted itself automatically for the lighting in the room.

Mac OSX USB-Serial Adapter

At work I occasionally need to work with devices that have serial interfaces, like Cisco Access points, and wanted to do so with my MacBook. One particular USB-to-Serial adapter that I found works OK is a Sabrent SBT-USC1K, which uses the same MacOSX Prolific driver I had installed a while back for use with a GPS. I've used this on both MacOSX Tiger (10.4) and Leopard (10.5).

There are probably lots of USB-Serial adapters that work with a Mac, and even use that same driver. I just thought I'd jot down one in particular, so someone doesn't have to make a wild guess and order something hoping it happens to work with OSX.

Logitech QuickCam Pro 5000 on a Mac Mini

I was recently working on finding a reasonable webcam that would work with an Intel Mac Mini, since Apple no longer sells the iSight and the prices for them on eBay are outrageous.

After reading reports that newer versions of the Logitech QuickCam Pro 5000 (labeled as "Vista Ready") worked on Macs, I picked one up and tried it out on my Intel MacBook laptop, running OSX 10.4.8 at the time I believe.

Despite what I had read on various postings, the camera didn't show up at all, although the built-in microphone worked OK, appearing as something like "Unknown USB Audio Device". The camera worked OK in Windows, so I figured the hardware was OK - and returned it to the store and started looking again.

After a while, 10.4.9 came out, and supposedly included updates that supported more webcams. I bought another QuickCam Pro 5000, and this time found that the camera and microphone worked in iChat, but the version of Skype I had at the time ( only saw the microphone.

I figured this was good enough and took it out to the person with the Mini. While there, I updated OSX to 10.4.10. When I plugged in the QuickCam, I found that the camera worked, but now the microphone didn't show up at all. When plugged into my 10.4.9 laptop, the camera and mic worked fine. Apparently Apple broke something in the 10.4.10 update. (there's a discussion of it here.)

After poking around, I found the AppleUSBAudio system extension, which seemed like a likely suspect. By replacing it with the same extension from 10.4.9, I was able to get the mic working - it went something like:

sudo -s
(type in password)

cd /System/Library/Extensions
kextunload AppleUSBAudio.kext

(backup the AppleUSBAudio.kext directory somewhere else)
(copy the 10.4.9 AppleUSBAudio.kext directory to this directory)

(permissions got changed moving between machines, fix that up)
chown -R root:wheel AppleUSBAudio.kext  

kextload AppleUSBAudio.kext

Plugged in the webcam, and now both camera and mic work. Tried a newer Skype -, and that works too.

So I think we'll be able to chat between the Mac Mini and the MacBook for a while - at least until Apple updates the OS again.

In a followup entry, I replaced this camera with a Logitech QuickCam Communicate STX.


Since I'm fooling around with USB GPS stuff today, also figured I'd stick the Holux in my MacBook (which I'm really loving). Found the gpsdX FAQ was a good starting point. Downloaded and installed the Prolific driver from the link in the FAQ, rebooted, and now see a /dev/tty.usbserial appeared.

Once the machine was back up, installed gpsdX which installed like most other Mac programs, ran the gpsdXConfig app to select the tty.usbserial device, and that was about it. Am now able to telnet localhost 2947 and type some simple commands like d to get the date from the GPS. KisMAC seems to work fine with it, and the gps2geX app fired up Google Earth, zoomed down and put an icon right on the roof of my house - pretty slick.