Maccast Members 036 - 2010.08.22
V Follow-up on router security
V My pal George tells me MAC address filtering is pointless since the address is in the packet headers unencrypted.
* It's not possible to encrypt Mac addresses. If you did that packets couldn't flow as a device would not know when packets are sent to it.
* The payload of the packet is encrypted, but the sender and receiver layer two (aka Mac addresses) can't be or you could not send and receive between network cards.
V OS X Alias vs. Symbolic
* What are the differences between OS X aliases and symbolic links.
V Anatomy of an alias
* Apple's developer site has some info on Aliases vs. symbolic links
V Aliases and symbolic links are lightweight references to files and folders.
* That just means they are little files (or data references) with information that points to the original file.
* when you select or try to open the alias in one location to actually opens the file or folder in the other location.
* You can delete aliases and the originals remain
V On HFS and HFS+ file systems, each file and folder has a unique, persistent identity. Aliases use this identity along with pathname information to find files and folders on the same volume.
* On the same volume is important, but confusing.
* Aliases will not work across volumes or partitions, but if you move the original across volumes then the link breaks.
V Moving or even re-naming originals on the same volume is OK and the alias will even still find the original
* Beginning with OS 10.2 when you click an alias OS X will check for a file or folder (with the same name) at the original file path and it if finds the item there it will open that item.
V If it doesn't find the item, it then uses the unique, persistent identity to find the original item.
* As long as it's still on the volume that the alias was created on.
* The original item could even have been re-named.
V The exception is if you place a new file or folder with the same name at the original location that the alias pointed to.
* If that is the case the alias will update and point to the new file, since it resolves the path information first and only uses the unique identifier if it can't find the item with the original path data.
V How to create aliases
* Control+Click and item in the finder and choose 'Make Alias'
* File-->Make Alias (Command+L)
* Drag with the Command+Option keys held down.
V Alias are generally great in the Finder and for most OS X applications, but fail in some applications.
* Because it is an actual file programs like Dropbox just see it as a file.
* Some can't follow the path
* Unix-level commands and utilities do not understand aliases. They just see a file
V Enter Symbolic links
* Just like aliases, but in the UNIX world
* They are "dumb" and just contain a pointer to the original
* If you move or rename the original the link breaks.
* Have to create them in the Terminal or with a dedicated app.
V But the advantage over an Alias is that as a low system level apps can follow them
* If you create a symbolic link inside Dropbox then anything you add in that alias from outside the dropbox folder will be uploaded to dropbox.
* To dropbox the symbolic link looks just like the original folder, not just a file.
V Ways to create symbolic links
V Terminal
* ln -s [/path/for/your/original_file.txt] [/path/to/alias.symlink]
* remember you can drag an item from the Finder into the Terminal window to have it's full path populated.
V Automator services or AppleScript
V Automator Service
* Open it in Automator
* Choose “Save as” to save it in your Services folder (which is in your home folder Library/Services).
* Now it will be an option in Services in the Finder. Just control+click. Services-->Create Symbolic Link
V 3rd party apps
V Path Finder
* File-->Make Alias-->Make Symbolic Link
* SymbolicLinker, runs as a service in 10.6 and a Contextual Menu Item in earlier versions of OS X
V Alias your protected images
* Alias or sym link will work.
V Closing
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* ideas for topics, subjects you'd like covered, etc.