Print a File - Remove Blank Lines and Comments

A favorite Grep command...

grep -v '^$\|^\s*\#' squid.conf

OS X Yosemite - Create Boot Disk

There are multiple ways to create a boot disk, this is just one that I've found simple and efficient.

Steps:

1. Connect a formatted 8GB (or larger) usb drive, and rename the drive Yosemite. (The Terminal command used here assumes the drive is named Yosemite.) Also, make sure the Yosemite installer, called Install OS X Yosemite.app, is in its default location in your main Applications folder (/Applications). 
2. Run the following command (remember the file must be in the right location and the usb drive named "Yosemite" or change the command to match the name you've selected): 

   sudo /Applications/Install\ OS\ X\ Yosemite.app/Contents/Resources/createinstallmedia --volume /Volumes/Yosemite --applicationpath /Applications/Install\ OS\ X\ Yosemite.app --nointeraction

3. Launch Terminal app.  Warning: This step will erase the usb drive. Paste the copied command into Terminal and press Return.
4. Type your admin account password when prompted.
5. You'll see the following... Erasing Disk: 0%... 10 percent...20 percent... etc. Wait until you see the text Copy Complete. Done. This step may take 20 minutes or more to complete as it is copying a large amount of data.

You now have a bootable install drive.