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badtz · Dec 14, 2005, 12:11 PM

I recently installed (and now using) Symbolic Linker to create a symbolic link to my home folder's "Application Support" folder onto a secondary HD.

Are there any negative consequences to doing this? I'm wondering if this will create any problems later with OS X not being able to save and properly forward information to that directory..

?

Tesseract · Dec 14, 2005, 12:30 PM

As long as the secondary HD is always present, you should be fine. What you are doing is one of the things symbolic links were designed for.

If for some reason the secondary HD is not attached or not working, then you'll have a 'broken symlink' and apps and/or the OS might start giving you error messages.

Artanis · Dec 14, 2005, 12:43 PM

Originally Posted by badtz

I recently installed (and now using) Symbolic Linker to create a symbolic link to my home folder's "Application Support" folder onto a secondary HD.

Are there any negative consequences to doing this? I'm wondering if this will create any problems later with OS X not being able to save and properly forward information to that directory..

?

Where can I get this program from?

Tesseract · Dec 14, 2005, 12:49 PM

I assume badtz is talking about this app: http://seiryu.home.comcast.net/symboliclinker.html

Located with the help of macupdate.com

badtz · Dec 14, 2005, 01:15 PM

Originally Posted by Tesseract

As long as the secondary HD is always present, you should be fine. What you are doing is one of the things symbolic links were designed for.

If for some reason the secondary HD is not attached or not working, then you'll have a 'broken symlink' and apps and/or the OS might start giving you error messages.

Is something like this able to be done using "aliases" instead of symbolic links? If I read correctly, OS X won't do the same with aliases, but it will forward things properly w/symlinks.

Hopefully my internet 2nd HD doesn't stop running anytime soon

Tesseract · Dec 14, 2005, 01:31 PM

I don't know whether an alias would work for this purpose or not. The symlink definitely will.

Chuckit · Dec 14, 2005, 01:57 PM

I don't see why an alias wouldn't work for this. The only difference would be if you for some reason renamed your Application Support folder and put another one in its place. The alias would point to the old, renamed folder, while a symlink always points to the exact same path.

P · Dec 14, 2005, 02:23 PM

Originally Posted by badtz

Is something like this able to be done using "aliases" instead of symbolic links? If I read correctly, OS X won't do the same with aliases, but it will forward things properly w/symlinks.

Hopefully my internet 2nd HD doesn't stop running anytime soon

Depends on which program will use it. Generally no, though.

Aliases are resolved at a higher level than symlinks. Symlinks come from the BSD layer and are support by all layers above it. Aliases come from Carbon and are not resolved by the filesystem driver.

IMO, using aliases instead of symlinks in OS X was one of Apple's mistakes in the transition. Both aliases and symlinks are supported by the Finder, but if you make an alias from the Finder you make an OS 9-style alias. It would have been easy to make it a symlink instead. The reason they didn't is that OS 9 and below don't support symlinks. I can't think that it would have been hard to add support for symlinks to the HFS+-driver in OS 9. In fact, why not add it to all the older versions via the Carbon libs - or already when implementing the HFS+ driver in OS 8.1? Aliases is one thing I wish would have been deprecated long ago. It's bordering on the absurd to have three levels of shortcuts in the OS with varying levels of support.

Tesseract · 02:31 PM

Originally Posted by P

Depends on which program will use it. Generally no, though.

Aliases are resolved at a higher level than symlinks. Symlinks come from the BSD layer and are support by all layers above it. Aliases come from Carbon and are not resolved by the filesystem driver.

IMO, using aliases instead of symlinks in OS X was one of Apple's mistakes in the transition. Both aliases and symlinks are supported by the Finder, but if you make an alias from the Finder you make an OS 9-style alias. It would have been easy to make it a symlink instead. The reason they didn't is that OS 9 and below don't support symlinks. I can't think that it would have been hard to add support for symlinks to the HFS+-driver in OS 9. In fact, why not add it to all the older versions via the Carbon libs - or already when implementing the HFS+ driver in OS 8.1? Aliases is one thing I wish would have been deprecated long ago. It's bordering on the absurd to have three levels of shortcuts in the OS with varying levels of support.

A symlink points to a path. An alias points to a filesystem object. Aliases have the advantage that they won't break if the target of the alias is moved, so there is still at least one reason to use aliases. Apple could have decided to have the Finder support making both, but that might have been confusing to less savvy users. So they stuck with the (familiar) alias.

Dog Like Nature · Dec 14, 2005, 03:04 PM

Originally Posted by Tesseract

A symlink points to a path. An alias points to a filesystem object. Aliases have the advantage that they won't break if the target of the alias is moved

True, but hard links do point to inodes (i.e filesystem objects).
Of course, hard links don't work across volumes, so the point is moot.

badtz · Dec 14, 2005, 04:07 PM

Originally Posted by P

Depends on which program will use it. Generally no, though.

Aliases are resolved at a higher level than symlinks. Symlinks come from the BSD layer and are support by all layers above it. Aliases come from Carbon and are not resolved by the filesystem driver.

thanks P for the thorough answer!

That's what I remember reading about [diff. between the two].

Do you happen to know in the case of the Application Support folder / Preferences folder, if aliases would work?

Currently I have it set up usinsg symlinks, and my folder hierarchy on the secondary HD is fine.

But I'm just curious about using OS X's aliases, in case I decide to modify the names and rearrange the folders on the secondary HD in the future.

If aliases don't work in this instance, then I'll just stick with the symlinks and the way I currently have things set up

QUESTION: what happens if you create a symlink to the /Library (not ~/Library) folder, and you have multiple users on the computer. What would happen if you turned on the option "ignore ownership of this volume" in the Get Info window for the secondary drive? Wouldn't this allow users to delete those files without admin permissions? curious.

Tesseract · Dec 14, 2005, 04:22 PM

Originally Posted by badtz

QUESTION: what happens if you create a symlink to the /Library (not ~/Library) folder, and you have multiple users on the computer. What would happen if you turned on the option "ignore ownership of this volume" in the Get Info window for the secondary drive? Wouldn't this allow users to delete those files without admin permissions? curious.

It would. Don't do that.

(The reason: symlinks don't have permissions of their own; the only permissions are on the files the symlink points to. If those files are on a drive that has its permissions ignored, the permissions are ignored just as if there were no symlink.)

badtz · Dec 14, 2005, 04:52 PM

Originally Posted by Tesseract

It would. Don't do that.

(The reason: symlinks don't have permissions of their own; the only permissions are on the files the symlink points to. If those files are on a drive that has its permissions ignored, the permissions are ignored just as if there were no symlink.)

gotcha. just making sure

Artanis · Dec 15, 2005, 06:15 AM

U guys are good.

I have a question. I want to use symbolic linker to create a link for a file that is in a folder wich has password protection. The folder is mine, I know the password...........
The password is created with Lame Secure

So can u guys help me?

Thanx

badtz · Dec 15, 2005, 06:23 AM

Can OS X at any point lose the link for a symlink?

I have a feeling that this might have just happened to me [presumably after installing some software updates via software update] .....

I went back into my /Library and saw that "application support" wasn't a symlink anymore to my 2nd HD and the folder was re-created and all the new apps I just opened created their folders in Application Support but on the primary HD.

are there any cases where OS X will dump symlinks? I definitely don't want to find out about this later