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Past Episodes

#328 HeyTell, Hack Mifi Cable, ScreenFlow 3, Seismic Isolation, SSL Certificates, Plists Demystified

I’ll be speaking on Mac Mania 15 to Autralia in November of 2012 with Don McAllister and Leo LaPorte on Insight Cruises. Mistaken Marks and mispronunciation. Rod Simmons reviews HeyTell and Jonathan Quinlan answers Professor Albert’s question about bits and bytes. I created a ScreenSteps tutorial including embedded video on how and why to hack the USB cable for the Novatel Mifi 4G 4510L from Verizon. Paul from Peru explains Seismic Isolation and I tell my own anecdote about it. Full review of ScreenFlow 3 from telestream.net. Ken Wolf from the Manhattan Repertory Theater in New York City does a testimonial about TextExpander. In Chit Chat Across the Pond Bart explains the SSL Certificate drama (hint: don’t use Safari for a while), he gives more detail on how secure File Vault 2 is for whole disk encryption, and Bart answers Pierre Bourgeois’ “dumb question” about what a plist actually is and why do they get mucked up.

itunes

Hi this is Allison Sheridan of the NosillaCast Mac Podcast, hosted at Podfeet.com, a technology geek podcast with an EVER so slight Macintosh bias. Today is Sunday September 4th, 2011 and this is show number 328.

MacMania 2012

I can’t believe I forgot to tell you something REALLY exciting last week! Have you ever heard of the Mac Mania Cruises? Captain Neil of Insight Cruises is the mastermind – he buys something like 300 rooms on a Holland America cruise ship that holds maybe 2000 people. He then arranges speakers on a specific topic, say history, or science or astronomy, or in this case, the Mac. You do pay an extra fee to go to this conference at sea, but you get sort of a private party feel on the ship – you eat meals and play with people all of the same interest. I’ve wanted to go on one of these cruises forever. Leo LaPorte speaks on lots of them, and our good friend Don McAllister has spoken on the last few too.

Well, I get to be one of the speakers on MacMania 15! It’s not until November of 2012, but I’m so excited already! Leo and Don are also speaking as is Wally Cherwinski. Don and I have to do most of the heavy lifting – get this – we have to do eight NINETY MINUTE seminars! Isn’t that insane? Steve gets to go with me, but he gets the best deal – the trip without any of the work. Of course he’ll have the job of talking me down off the ceiling for the last couple of weeks before we go as I’m frantically trying to get prepared. I freak out before vacations anyway, this will be insanity – he may need to anesthetize me.

Oh wait – I forgot to tell you where Mac Mania 15 goes. It starts in Sydney Australia, goes up the east coast, and then out to New Caledonia, a French-owned island off the coast, and then back down to Sydney. But get this. There’s a Sky and Telescope group going on the same cruise…because there’s a total eclipse of the sun while we’re on our way to New Caledonia! It’s actually on the agenda – 7 pm cocktails and solar eclipse. Isn’t that crazy?

I put a link in the shownotes to the Insight Cruises site where you can read all about the trip and what Don and I are going to be talking about.

Errata

I have a couple of important corrections to last week’s show.

Dean on Leo Apotheker

Last week I talked about the HP story, and I referred to the CEO as Leo Apotheker. I got a call from listener Dean to correct my pronunciation. He said the CEO’s name is pronounced Leo Apotheker. There, did I say it right Dean? He knows this because he used to work for the man at SAP. Dean also said I could very well be right in my assessment of Leo as being smart like a fox.

Mixed up Marks

I was alerted by Kevin Allder, aka @Big_in_VA, aka Steve’s wingman, that in my discussion with Rod Simmons last week, I inadvertently referred to Mark Sheppard as my pusher, when in fact the real gear dealer who costs me a fortune is Mark Dalton. To be fair, the chat room during the live show is a veritable HIVE of Marks. in fact, I may just start calling EVERYONE Mark to make it easier on me. In any case, my deepest apologies for any harm done to the character of one of the finest members of the NosillaCast crew, Mark Sheppard. now wait, which one is Switcher Mark then?

NosillaCast News

While we’re doing administrative stuff – I haven’t mentioned the NosillaCast News in a while. The show comes out pretty much like clockwork, so there’s not always a big thing to chat about but subscribing to the newsletter would let you know if anything big was happening, like my site being down or the feed being boogered, that sort of thing. If you subscribe using the easy little form on podfeet.com you’ll always know if things are going on swimmingly like usual or if something odd has occurred. I really encourage you to subscribe to the NosillaCast News.

Rod Simmons on HeyTell

Rod’s written review of the free iPhone App HeyTell.

Well I’ve been having a blast with HeyTell ever since I heard Rod’s review. I installed it and instantly started having voice conversations with Rod. I think convinced my friend Diane to try it on her iPhone and we had a blast with it too. I think she put it best – it’s like a walkie talkie, but you don’t have to answer it that quickly! She was really excited to find out that it was cross-platform, since her son is on Android. I’m sure he’ll be thrilled to get voice messages this way from his mom, right? We also noted an interesting use case – we can’t text while driving (not if we’ve got a single functioning brain cell in our heads, but if you leave HeyTell open when you turn off your phone, it will play the messages immediately while you’re driving. Then, by simply holding your thumb down on the phone, you can answer. It seemed a LOT safer than text messaging and accomplished the same thing. Of course doing neither would be even safer. anyway, I put a Link to HeyTell in iTunes in the shownotes so you can play too.

Jonathan Quinlan Answers Professor Albert

When Katie hijacked the show, Professor Albert called in with some questions for the listeners to answer. Listen as jonathan Quinlan (aka @jquinlan96) answers what is a kilobyte, does it bite, and do you die from it?

ScreenSteps

A few weeks ago I reviewed a whole slew of wireless hotspots and finally settled on the Novatel Mifi 4G 4510L from Verizon. I liked everything about the device EXCEPT that it wouldn’t charge and operate as a hotspot at the same time. I did some hunting around for a solution and from a Verizon Wireless message board I discovered that you could hack the USB cable itself to fix the problem. Some people would tell you that a charge-only cable would work, but they don’t. You have to cut the wire in half, strip back the insulation, strip back the wires on either side and then short the green/white data pair in order to trick the device into working, just not having the data wires doesn’t fix the problem. I decided to give it a try and I was successful, and only for a couple of dollars.

While I was doing it, I took a bunch of photos of my progress, because I had a plan. I decided before I did it to create a ScreenSteps tutorial to post to my blog so that I could teach other people how to do it. I mean, duh, right? What good is it knowing stuff if you don’t teach other people?

Then I got to thinking how cool a video would be, but of course a video of stripping wires and soldering wouldn’t be all that interesting. What would be interesting though would be a demonstration of the behavior of the mifi (not working) before the hack and working great after the hack. So I finally took advantage of a feature that’s been in ScreenSteps for ages and ages, and embedded my video right into the ScreenSteps lesson. I uploaded the video to YouTube, grabbed the embed code and slapped it right into ScreenSteps. Easy as pie. I pushed publish to my blog as a Page so that it can be one of my Tutorials right from the menu bar of my Web site. I’d love it if you checked it out, even if you don’t need to do this hack, I’m pretty darn proud of it!

Link to tutorial on How to Make Your Own Charge-Only USB Cable for the Novatel Mifi 4510L

I have so much fun (as you can tell) when I use ScreenSteps, I really hope you’ll check it out yourself. They have a free 30 day trial, what do you have to lose? check it out at ScreenSteps.com. It’s only $40 to be able to do what I did! You may also want to check out the free public beta for the Mac of their newest product, Clarify from bluemangolearning.com/clarify.

Paul from Peru on Seismic Isolation

I’ve mentioned a lot of times that I purposely named the podcast with a vague name so that I could talk about whatever fascinated me. Many years ago I got an email from an engineering student in Peru named Paul Korswagen. Over the years I’ve enjoyed hearing about his engineering degree work, very much like pen pals chatting. Paul decided, in keeping with my “talk about what interests me”, that he’d teach us about seismic isolation. Let’s hear what he has to say:

Hi Allison and fellow Nosillacast listeners this is Paul from Peru, and I’m here with a A brief and not too technical overview on seismic isolation. Since Allison likes to include a great variety of topics in her podcast, I thought she’d like a brief explanation of what seismic isolation is.

Isolated buildings exist since the 80’ies, and if you live in a seismic area you’ve probably used some seismic isolated structures, although probably just bridges. Japan is the world’s leader in seismic isolation with thousands of isolated buildings.

First, to understand seismic isolation we need a bit of background into structure and earthquake dynamics. Lets start with a practical example: Take a metallic ruler or any object that is rigid enough to stand upright and flexible enough to oscillate if you move it at the base. Now, wiggle its base and you’ll notice that at a certain speed (frequency), the ruler will bend the most; if you wiggle its base really fast it will probably not move much more than your hand, and perhaps the tip moves less. Now, hold a pen to the ruler’s top end and try to make it oscillate: it should now require a slower vibrating frequency to reach the maximum movement at the top. This is because every configuration has a specific frequency at which it would naturally vibrate if you were to give it a first impulse. A building is no different, so when an earthquake comes, it will vibrate differently depending on what frequency the earthquake has. If the natural frequency of the building were very different to the one of the earthquake, it would hardly move at all.

And the more a building moves or more precisely, the more adjacent stories move relating to each other, the more damage the structure will take, windows will shatter and plumbing will fail. Also, the harder a building vibrates, the more its contents will suffer: shelfs will fall over, appliances and special equipment will break, etc.

The problem is that buildings can’t be constructed so that they have a specific natural frequency that avoids the earthquakes’ movement. First, it would be technically very difficult to build a structure with a frequency lower than ¼ Hz (that means it moves back and fourth one time in 4 seconds). Most buildings have a natural frequency between 1 and 10 Hz which depend on their mass and their flexibility. Secondly, they don’t necessarily have one predominant natural frequency (like the ruler) but can have a couple of important vibrating modes (theoretically they are an infinite number), so depending on how they are moved, they will vibrate taking different forms.

Another problem is that earthquakes have a big range of frequencies, that means, the earth moves at many frequencies at the same time, usually from 0.3 Hz to 10 Hz. The range varies depending on the type of ground you’re standing on and how the earthquake is produced: earthquakes are different around the world.

So, “what is seismic isolation” you ask? The concept is very simple, you put the whole building on top of a device that deforms easily (think rubber), so that when the earthquake comes, the ground moves but the building stays relatively stationary (because of its inertia). In the case of bridges, the flexible layer is installed between the deck and the piers. These isolation devices can actually include layers of rubber in such a way that they deform easily in one direction but are stiff on its vertical direction, otherwise they would crush under the weight of the building. There are others that use friction or the principle of an inverted pendulum, but they all do the same thing: create a flexible layer between the ground and the structure.

And how does this affect building dynamics? First, the system isolation_layer-building can be designed so that its natural frequency is between 0.25 and 0.5 Hz. Most earthquakes, on a good soil, don’t move slower than 1 Hz, so you can effectively have a building that almost doesn’t move during an earthquake. Secondly, because the natural frequency of the building is very slow, when it moves, its contents won’t be damaged. This is very important in buildings that house expensive equipment like servers and MRI-type machines. Thirdly, the isolated natural frequency of the building becomes strongly dominant, so there is no fear of the building taking other modes of vibrating. And fourthly, the isolation devices can add a bit of dampening to the structure, so that once it starts moving it will try to stop quicker.

Of course, seismic isolation has its compromises: there has to be a lot of space around the building in order for it to move, because with a flexible base, the building will move considerably more that a fixed-based one. Also, the plumbing and wiring connections must be able to take the distortion, the plane above the isolators must be rigid, so that all isolators move the same and, the price for the isolation devices is not yet justifiable for all types of buildings. Besides, isolation doesn’t work everywhere, for example if you were to build an isolated structure in Mexico city it wouldn’t help much, because the soil amplifies the earthquake’s vibration at the slow end with a predominant frequency of 0.5 Hz.

I hope I got you a bit interested in structures and earthquakes and that you’ve enjoyed this article.

Thanks Paul, this was great! I bet no other podcast has had an explanation of seismic isolation! I have a great story for you that goes right with this. When I was in graduate school, I took a rotation through our structural engineering organization at work. Our boss, DOCTOR Holman thought I was an idiot. Ok, perhaps I’m not the #1 engineer in the company but I do all right. Many years later, when I was working in the design organization, someone designed a laser that was to stand on four “legs” as vibration isolators.

Before I go on, a bit of background (which it sounds like you’d already know, but just in case). So there’s the natural frequency (which is hard to calculate) but there’s also how much something will react when rung at it’s natural frequency. That’s called the Q of the system, which is essentially the multiplier to be applied when the device (or building in your example) hits the natural frequency. A tuning fork has a VERY high Q because it’s got no dampening at all, so a graph of amplitude on the vertical scale and frequency on the horizontal scale would give you a very tall but narrow spike around the natural frequency. Take a building, which has a lot of natural dampening, and that same curve would be short and wide.

So, in mechanical vibration analysis, we build these very elegant models of the structure, and run it through very very expensive software to analyze it’s characteristics under dynamic conditions. All this hardware and software and modeling – right before the analyst starts the job on the computer, he or she GUESS Q. yup. they guess. and they almost always guess that Q is 10.

So back to our little laser up on it’s four little legs. DOCTOR Holman for some reason was taken out of mothballs and asked to do the analysis. He guessed that Q was 10, and ran the analysis. They built the model, and took it down to the vibration lab, and started shaking it – and suddenly all four legs snapped right off and the laser shot across the room! Q was actually 100.

The reason I love this story was that the design organization (of which I was now a part) was asked to come in and figure out what could possibly have gone wrong. I was assigned to the project. It was awesome. In 10 minutes of looking at the design I found probably three major flaws – sharp corners, no surface finish, even the wrong materials were chosen, and of course, no dampening material. It was as if they had put the laser up on four poorly made tuning forks!

So you can see this is a subject near and dear to my heart – it’s probably been 25 years since that happened and I still smile at the thought that I was brought to come in and fix DOCTOR Holman’s mistakes.

ScreenFlow 3

Every once in a while you find a software developer who consistently creates outstanding products. There’s a lot of great developers out there, don’t get me wrong, but one hit wonders are far more frequent than companies that relentlessly create quality products. One of those companies is Telestream, from telestream.net. I’ve reviewed many of their programs, most recently Wirecast 4 that allows me to create my live show and broadcast it to multiple services like Justin.tv, supports HD video, lower thirds, all kinds of cool features that give the impression I’m a professional.

This time I’m going to talk to you about their screencasting software ScreenFlow. Bart first talked about ScreenFlow back in 2008, I reviewed ScreenFlow 2 in 2009, and now we have ScreenFlow 3. I have to tell you, when I heard about ScreenFlow 3 coming out, I tried to think what they could do to make it better. You may know that I’m saddled with Windows at work, so all my screencasting there has to be done using Camtasia. It’s horrible. it’s clunky, it’s buggy, it loses data, it’s unpredictable, and it even gets voice and video out of sync, it takes FOREVER to encode on a workstation class machine, AND it costs $300. Other than that I’m really quite fond of it. Now consider ScreenFlow that’s beautiful and elegant, intuitive, and actually WORKS, and it’s only $99. If you’re a fan of ScreenFlow and have version 2, you’ll also be interested in this review since the upgrade cost is only $30 to go from version 2 to 3.

Like I said, I enjoy the ScreenFlow experience so much I was wondering what they could do to improve it. They’ve included a laundry list of new features. The first and possibly most important thing is that they’ve upgraded to support Lion features like autosave, version control and full screen capability. That by itself is worth the $30 but let’s see what else it can do.

I find it really useful on my videos using the craptastic Camtasia (when I can beat it into submission) to include annotations. Since this is screencasting software, it makes sense that you’d want to highlight an area, draw a box around it, or put a big giant arrow pointing to the thing you’re trying to explain on screen (a la ScreenSteps, right?) ScreenFlow 3 adds that capability. You can freehand draw lines with all kinds of endpoints and draw filled or transparent boxes or circles around items to grab the viewer’s attention. One thing I wish they’d included, and perhaps I just didn’t find it, would be the ability to create a highlight box – like a translucent yellow box. I couldn’t change the opacity of the boxes in the annotation.

However, there’s a callout function that does provide most of that functionality. In callouts you can either have your cursor surrounded by a circle to show exactly where you’re pointing, or you can draw a freehand rectangle. When you create a callout, it automatically makes the rest of the video darker so it highlights the callout area. I had trouble getting some of this function to work properly. One of the options is to blur the background, but it repeatedly blurred what was inside my callout as well. I’m certain that’s not the desired behavior, so it looks like I’ve uncovered a little bug.

Creating text boxes is super fun – if you have actual artistic talent you can use the tools they provide to add gradient fills to the text and the background of the callout, play with the fonts, and add outlines to the text. I say if you have actual artistic talent, because I managed to make a nasty looking text box with purple to green gradient on the text and a puke orange background. Art is definitely not in my talent set!

I was going to say that I wanted an enhancement to be able to add transitions to text boxes, but I kept poking at it and figured it out. If you hover over the text box in the timeline, and you’ll see a little gear, and sure enough you can add transitions. You can also right click on any kind of clip including Text clips and get to the transitions. I should have assumed that Telestream wouldn’t leave me wanting!

There are a ton of enhancements to video editing that I didn’t even get a chance to test, like how you can now reorder, delete and resize the height of your tracks; group clips; insert gaps; and select and remove gaps.

They’ve also added audio quality controls like the ability to remove background noise and smooth volume levels. You can view the audio waveforms and increase the size visually so you can see what you’re doing. This lets you see where your audio peaks and then view those peaks as you modify the audio with the quality controls. I really enjoyed messing around with the audio (you know I’m an audio person, right?) I’m not sure I’d use some of the effects for the kind of work I do, but I was astonished at how well the “remove background noise” filter worked. The great thing about ScreenFlow is that you get pretty much instant gratification on all the effects, in just a few seconds you can listen to the change the filter or effect made, and they give you a cool animation on the audio waveform to entertain you for those few seconds.

You can publish from ScreenFlow directly to YouTube, Vimeo, Flash, or to your disk using some nice presets like the new one for viewing on the iPad. And if you want to ruin your life you can go into the custom settings and start fiddling around…like I do!

It’s time for the bottom line. I’ve tested out a fair number of video editors (even been playing with Final Cut Pro X this week) and by far ScreenFlow is my favorite. I wish I had ScreenFlow at work, that’s for sure. ScreenFlow is fairly priced at $100, lower than Camtasia for Mac (WAY lower than Camtasia for Windows). If you’ve got ScreenFlow 2, the $30 upgrade is more than worth it, even if it’s only to get autosave and versioning from Lion. I can without reservation recommend ScreenFlow from Telestream.net.

Now it’s time for a confession. I told you earlier about a video I produced to embed in the ScreenSteps tutorial on hacking the Mifi charging cable, right? Well I tried to create it in Final Cut Pro X, but the titles gave me fits, and I found that certain things seemed very unpredictable. I probably spent two hours on it and while I learned a lot, I was fairly frustrated. I also had Bart try to convince me that iMovie has an intuitive interface; I couldn’t disagree more. The lack of a linear timeline drives me batty. Then I got a crazy idea – what if I tried to use ScreenFlow to do it? I know, ScreenFlow is a screencasting app, but you can instantly drag in any video clip (takes forever in iMovie), you can add transitions, you can add titles, you can drag in music, you can edit in a lovely timeline view…and guess what? It worked PERFECTLY! In less than an hour I had my movie complete and ready to export to disk. Even the export took way less time than the other tools. So don’t tell the Telestream guys, but ScreenFlow is a fantastic, simple, editor for making movies too!

Smile

I’ve asked you guys to tell me how you use TextExpander from Smile smilesoftware.com and Ken Wolf gladly wrote the following testimonial – I think he’s more passionate about TextExpander than I am!

This is Ken Wolf from Manhattan Repertory Theatre in New York City. I was listening to your Podcast today as you talked about one of the many uses of TextExpander and I thought I would let you know about how I use TextExpander and how it literally saves me thousands of keystrokes a day.

Here at Manhattan Rep, we produce a lot of new theatre. Over 6 years, we have produced over 600 plays – so that averages out to about 100 plays a year. All our communication with the creative teams putting together new plays is done by email. Of course, I use the standard signature snippet, but what I do everyday to save copying time and thousands of keystrokes is to use TextExpander for ENTIRE letters.

For plays submissions, we have a standard TextExpander letter. 4 keystrokes and a 300 word letter appears. When we receive contracts and release forms, again another TextExpander snippet creates a response letter. When we accept plays for our theatre festivals, I use a combination of TextExpander snippets for different parts of the body of the letter, and another for the subject heading.

I have probably 20 different response letters with easy to remember snippets. TextExpander is awesome. At any given time, we can be dealing with up to 60 creative teams, and TextExpander helps me speed through Manhattan Rep’s email, giving me time to do all the other myriad of things that need to be done to run a successful Indie Theater in New York City. Honestly, I would pay $500 for TextExpander. $34.95 is a bargain for all the time I save.

To have a computer without TextExpander, is like running a Marathon without sneakers. It is just plain silly. TEXTEXPANDER is AWESOME! Your podcast couldn’t be supported by a better product.

With best regards, Ken Wolf, Artistic Director, Manhattan Repertory Theatre

Chit Chat Across the Pond

Security Light

SSL Drama:

  • A fraudulent SSL Cert for *.Google.com issued byDigiNotar is causing a lot of frantic activity all over the IT industry. FireFox have issued updates, as have Chrome, and Microsoft. Note the missing name – Apple have yet to respond :(
  • This fraudulent SSL Cert allows those in possession of the CERT to carry out man-in-the-middle attacks on SSL connections to any Google site on anyone who trusts the DigiNotar root cert (the root cert which signed the fraudulent cert)
  • Google are reporting attacks in the wild, mainly in Iran – http://googleonlinesecurity.blogspot.com/2011/08/update-on-attempted-man-in-middle.html
  • If you browse with IE, FireFox, or Chrome only, you will be fine assuming you are fully patched, however, Safari users are not protected in any way, so either don’t use Safari until Apple get their update out, or consider taking matters into your own hands and manually deleting the cert from your computer using the KeyChain Access app. (search for ‘DigiNotar’ and delete the one cert it finds)
  • http://us-cert.gov/current/#fraudulent_diginotar_ssl_certificate

As always happens when something makes big news, there are Irene phishing attacks doing the rounds

On Mark’s “Not Another Mac Podcast” Episode 19 (http://www.everydaymacsupport.com/Everyday_Mac_Support/Not_Another_Mac_Podcast/Entries/2011/8/31_Not_Another_Mac_Podcast_-_Episode_19.html)(the one where Kirschen and John F Braun were on) Jodi Spangler gave an interesting Lion tip. She said she was taking care of a client who had forgotten his password. She said she was able to boot the Lion machine holding down Command-R key, which booted into the recovery partition. From there she was able to run the password utility and get into the machine. That doesn’t sound too secure to me. Also, if you have whole disk encryption on the boot drive, this would still work, maybe?

Can’t find any details in the show notes, so somewhat in the dark here, but I can say the following:

1) if the password is in the keychain, it is encrypted, and cannot be extracted without the password to unlock the keychain

2) there is no way around whole disk encryption – without the password the drive is random gibberish. No way to get around it with any sort of recovery anything, you always need the password.

Main Topic -Dumb Question Corner

Pierre Bourgeios asks:

Here is a potential dumb question for you.In troubleshooting problems for myself or others, the solution is oft times to delete the Plist file and relaunch the software. This does often fix whatever is the particular mysterious ailment. I do not know what a plist file is and did some research with “the Google” but the explanations are over the head of this wannabe techie (remember I am an accountant by training so this limits my geeky-ness).

My dumb questions are:

What is a plist file?

Why does it get mucked up?

Why does deleting this file fix certain problems with software?

What is a PList File?

PList stands for property list, it is a file format for storing so-called key-value pairs. It is mostly used for storing Application settings in the OS X OS itself, and in OS X Apps that use Apple’s APIs (i.e. cocoa and carbon apps). The idea of PList files goes back to NeXTStep, but the format has changed since then, and there are now two modern PList formats, an easy to edit but less efficient XML one, and a more efficient but harder to edit binary one. If you’re curious you can open XML-based .plist files in any programming (plain text) editor, and see the XML, but that can be quite hard to interpret. An easier way to see the contents of any given PList file (XML or Binary) is to open it in XCode where it will show the keys and values, rather than the encoding of the keys and values (in older versions of XCode there was a stand-alone app for this called “Property List Editor”).

There are LOADS of PLists on your Mac. The terminal command below will show how many you have in just your account:

find ~ -name *\.plist | wc -l

When I run that command I find I have 1,934 of them!

On Windows this kind of key-value data is not stored in lots of separate files, but in the Registry. This means that all data for all apps is always in memory, while with the OS X system of lots of separate PList files, only the needed data is in memory at any time.

Why does it get mucked up?

Bad programming! Generally it’s not actually the plist file that is mucked up, but rather the values the app chose to store in it are triggering a bug in the app that is causing the app to crash. The file is fine, but the app is barfing on the data it stores. There is no valid reason for this to happen, it is always a bug!

Why does deleting this file fix certain problems with software?

When an app that uses PList files to store it’s preferences starts up, the first thing it does is check for a pre-existing PList file with the right name in your Library folder, if it finds one it uses it, so if that plist file has data that trips up the app in it, the app will keep crashing. However, if it doesn’t find a PList with the right name, it will create a default one, with all the default keys and values, so in effect it restores itself to a default state.

Nuking a PList file is the OS X equivalent of re-installing an app in Windows. Because Widnows uses a single central store for configuration and settings info (the Registry) it is very hard to kill the settings for just one app, so your only way to get back to a default state is to re-install the app, which will over-write all the settings in the registry with default values. For all the same reasons that a re-install often works in Windows, nuking an app’s PList file often works on OS X. It’s less work to nuke a plist file than to re-install though :)

I hope you’ll take a moment to drop a comment in on iTunes – like Ken Wolf did – thanks for a lovely review Ken! Remember you don’t have to say nice things – just go say SOMETHING!!!

That’s going to wind this up for this week, many thanks to our sponsors for helping to pay the bills: ScreenSteps, and Smile. Don’t forget to send in your Dumb Questions, comments and suggestions by emailing me at allison@podfeet.com, follow me on twitter at twitter.com/podfeet. If you want to join in the fun of the live show, head on over to podfeet.com/live on Sunday nights at 5pm Pacific Time. Thanks for listening, and stay subscribed.

2 comments to #328 HeyTell, Hack Mifi Cable, ScreenFlow 3, Seismic Isolation, SSL Certificates, Plists Demystified

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