Learning OS X

OS X includes Parental Control software and it’s a great way to filter out unwanted content on your family computer. However, sometimes this program causes problems with other applications. We used it for a while and noticed that we couldn’t use the iTunes Music Store or Gmail.

Searching the Internet for an answer, we found another way to filter out porn and other offensive material that is completely free. OpenDNS.

What is DNS?

DNS is a service that translates the a websites name (i.e., www.learningosx.com) to it’s IP address (192.168.1.100). When your computer is connected to your ISP, it sets it’s own DNS server. However, you can override this setting, change it to OpenDNS and in addition to having fast DNS lookups, you can add parental filters.

The filtering works by comparing the website address you are trying to go to to a “blacklist” of sites you want blocked. Any that are found in the blacklist are denied.

What’s really cool about this service is the basic features are totally free. You only need to have some comfort in adjusting your internet settings. The steps below will show you how.

Before you can use the free Internet Porn filter, you need to first sign-up at OpenDNS. Go to OpenDNS.com and create an account now and come on back here when you are done.

Open the System Preferences

Click on Network

Select the network connection marked Connected. It’s likely the first one.

Click the Advanced button

Select the DNS tab

Add 208.67.222.222 and 208.67.220.220 to the list of DNS servers.

Click OK

Then, the next step is to go back to the OpenDNS site and setup your filters. Go to the OpenDNS dashboard, signing in again if you have to.

On the top of the Dashboard you should see a Settings tab. Click it. It will take you to the Settings page.

You should then see a Web Content Filtering dialog that lets you adjust the filtering you want for your machine. I leave mine set to Moderate. Change yours and click Apply. Don’t worry, if you need to you can change it again.

At this point you are done. It usually takes a couple of minutes for the filters to kick in. You can test your configuration by going to Google and typing search terms that you think will return inappropriate results. I’ll leave the specifics as an exercise to the reader.

Special Note for Mac Book users. If you carry your laptop around and are often on other networks, you will need to run a utility that tells the OpenDNS website about your web address. You can read how to do this here.

Watching DVDs on your Mac is easy with the built in DVD player. You can launch it two ways.

1. Pop a DVD in your Super Drive and the DVD player launches.
2. Open the Applications folder and click the DVD Player icon.

Once a DVD starts playing, you can go to full screen mode by clicking Cmd-F

or How I learned to kill my badly behaving OS X apps.

This question comes up a lot so I thought it was worth a dedicated post. On Windows, when an application is in a hung state and your system becomes unresponsive you can press Ctrl + Alt + Del to open the task manager. There is an equivalent key sequence on OS X.

If you have a hung application pressing Alt+Cmd+Esc will bring up a list of running applications with a button to allow you to Force Quit the application. Select the application you want to close and click Force Quit should kill the offending applications. You can also access this dialog by clicking the Apple menu and choosing Force Quit.

That’s it pretty simple. Hopefully the Mac applications you have behave so well you never have to do this.

When you use the keyboard shortcuts to take screen grabs in OS X the default is to save them to the Desktop. If you are like me and you use these keys a lot, your desktop will quickly become crowded. What you need to do is change the default folder for screen shots.

I don’t know why this isn’t a System Preference but it’s pretty simple to change the defaults with a little Terminal-fu.

1. Open an OS X Terminal (Go to Utilities->Terminal)
2. Inside the terminal, issue the following command

defaults write com.apple.screencapture location /DESTINATION

where DESTINATION is the directory you wish to save to.

3. Logout and Log back in.

So, for example, if you create a Screenshots folder inside the Pictures directory your command would look like this:

defaults write com.apple.screencapture location ~/Pictures/Screenshots

That’s all there is to it. If you have any interesting system tweaks, let us know in the comments.

There are two ways you can grab screen shots from OS X. Through the use of built in shortcuts and by using the Grab utility.  I use this feature all the time when taking screenshots for Learning OS X. I’m also constantly using it to send images of error screens to customer support. It’s a great utility, it’s free and once you make it part of your arsenal, I guarntee you will use it on a regular basis.

The system short cuts for taking screen captures are

• Shift+⌘+3 to take a picture of the entire screen and save to a file
• Shift+Ctrl+⌘+3 to take a picture of the entire screen and save to the clipboard
• Shift+⌘+4 to take a picture of a rectangular area and save to a file
• Shift+Ctrl+⌘+4 to take a picture of a rectangular area and save to the clipboard

When they images are saved to a file, they are saved as a PDF or TIFF file to the desktop

I generally use the Control modifier to save them to the clipboard and then open Preview, paste them into the preview window and save the file.

Grab on the other hand is a Utility that you launch to allow you to take screen captures. There are a few cases where Grab is better for making screen captures then the system shortcuts.

• Grab lets you decide whether or not to include the cursor when you take a screen capture. If you are using the OS X system screen capture, the cursor is hidden
• Grab also lets you take delayed pictures of your desktop. This is useful if you need to setup a state before grabbing the image. You can do this by pressing Shift+⌘+Z

There you have it, two simple ways to grab beautiful screen captures from OS X. If you have any cool uses of Grab, let us know in the comments.