Mac OS X Boot, Sleep and Wake Time and Date

For several times I wondered what was the exact time my machine booted, woke up or slept. So, I did a little investigation to find out that's actually very simple to get those answers.

Using the Mac OS X Terminal, you can run the following commands:

 
- For System Boot Time, use: systcl -a | grep kern.boottime

You should get results similar to the picture below

- For System Sleep Time, use: sysctl -a | grep sleeptime

You should get results similar to the picture below  

- For System Wake Time, use: sysctl -a | grep waketime

You should get results similar to the picture below

I typically use the "uptime" command (just type uptime on the Mac OS X Terminal) to find out how long my machine has been powered on.

Lastly, you can get a short history of the machine boot using the "last reboot" command (just type last reboot on the Mac OS X Terminal) to get the last three boots of the system.

You can get the same information reviewing system log files but I think opening the terminal and typing a few commands easy enough to get the information you're looking for.

Debugging Oracle ADF Mobile Applications - Part I

I've been involved with the Oracle Mobile Application Framework (a.k.a. ADF Mobile) lately and one of the things developers typically ask me during my talks is how to debug mobile applications created with the Oracle framework.

To give you a little bit of context, the Oracle Mobile Application Framework does generate a hybrid app (native container + HTML/JavaScript) so standard debugging techniques apply here. The Oracle Mobile Application Framework has some other capabilities like running Java code on the device but that's a topic for another post.

So, there is more than one way for debugging Oracle-generated (read hybrid) applications depending on the platform your are own and the target device you are working on. I'll try to isolate specific use cases on different posts so you don't get distracted with irrelevant stuff.

The first one on the list is debugging Oracle Mobile Applications on iOS and Mac OS X.

The ingredients are:

- Oracle JDeveloper 11.1.2.4.0
- XCode 5.1 (for the Simulator)
- Apple Safari

The setup is pretty straightforward and here is what you have to do:

On the iOS Simulator (works on iOS +6.x), go to Settings > Safari > Advanced > and make sure Web Inspector is turned ON.

Open up the Safari web browser and enable the Develop features. To do that, go to Preferences > Advanced and check the Show Develop menu in the menu bar.

If you don't have an app deployed to the simulator yet, this is a good time to do so. Open up JDeveloper and deploy a simple application to the simulator (you can use the same approach with a real device but I'd rather start debugging on the simulator).

Once you have the app installed/deployed and running on your iOS simulator go to Safari and select the Develop menu.   

You should see something similar to the picture below where you select the iPhone Simulator and then the name of your application (in my case - MyWeatherChannel). The below HTML pages are part of your application and highlighting one of them in the Safari menu will also highlight them on the iOS simulator.

Selecting that highlighted page will bring Safari's Web Inspector up. Click on the first icon on the left (Resources) and that should show you the DOM for the page you selected.

At this point, you have many options but you may want to try enabling the Styles (click on the Styles button on the top menu) and make changes to the existing components on the page. That would give a good idea on what to look for when doing further debugging.

You can also manipulate the DOM to change the name or size of the labels and see how they are going to look like.

What is also very interesting are the Timelines (click on the Timelines button on the top menu) where you can see how long it takes to make a network request, to load different components of your application and the details of JavaScript calls.

The last thing I'd like to show you here is the option to enable the Console (click on the Console button on the top menu) and you can many other things like triggering commands or watching the console output. You can also reload the application by pressing Cmd + R.

In the test above, I just fired an alert command (alert("My Test Message");) from the console and saw the JavaScript alert on the simulator.

You can also change the current values (by also manipulating the DOM) in the app like the example below where the command: document.getElementById("ot3").innerHTML=72; changes the value of one the fields in the app.

Happy debugging!

Do Not Disturb!

To all of my friends out there with their powerful iOS 6 devices, you may haven't noticed yet but if you use the Do Not Disturb feature it will stay on after scheduled time and that's caused by a bug reported here: http://support.apple.com/kb/TS4510 and it will stay on until Jan, 07th 2013 causing your device to do not alert, notify, ring, etc (depending on your setup) until you turn DND off manually.

The mysterious behavior of Mac Mail and Yahoo! Mail Plus

If you, like me, uses Mac Mail as your primary email client and you also have an Yahoo! Mail Plus subscription (which gives you IMAP access to your Yahoo Mail account), you may have experienced an intermittent connection behavior where the email client is not able to connect due an invalid password even though you're using the correct one.

I've been reading lots of blog posts and forums reporting the exact same behavior and I was not able to find a concrete answer but the following approach seems to be working for me so far.

So, next time you see that dialog box requesting that you enter your password again to login to Yahoo, go to your web browser of choice and navigate to Yahoo Mail (mail.yahoo.com).

If you are automatically logged into the system then make sure you click on the Sign Out button first.

When you return to the login screen, type your username and password normally but make sure you select the Keep Me Signed In checkbox and then click Sign In. That should solve the problem.

Have fun...

Installing Erlang on Mac OS X Snow Leopard

I'm working with a customer who is using the Kaazing WebSocket Gateway - AMQP Edition with RabbitMQ and while his install was pretty straightforward on Windows 7 I thought the same would be applicable to my case (a Mac user). Well, to summarize the process, it was quite of a challenge to get everything working, not from the complexity perspective but for the number of steps involved in the process to get the environment running starting from the point that RabbitMQ depends on Erlang to run. So, that was the first step... Installing Erlang on Mac OS X

Here are the steps I had to take:

- Download and install Apple Xcode 4.3 from Apple's AppStore (yeah, you read it right!)

- The tricky part here was to enable Command Line Tools which is not selected by default in Xcode. To do that, go to Xcode Preferences --> Downloads --> Components and install Command Line Tools. It's just another 170MB over the already downloaded 1.35GB of Xcode :)

- Download Erlang latest release from http://www.erlang.org/download.html

- Extract the Erlang package (i.e. tar -xvf otp_src_R15B.tar) and navigate into the recently created directory

- Run ./configure

- Run ./make

- Run sudo make install

Hope this help you to get your project going...