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Automatically added Symlinks removal?

Posted: 15 Oct 2017, 15:29
by Kellemora
Hi Yogi

Back when they switched from Thunderbird to IceDove, we had to manually rename and copy our .thunderbird to .icedove which was no problem at all.

I just upgraded my computers to Debian 9.2
With this distribution upgrade, they changed the name of IceDove back to Thunderbird.
Only now I have TWO files in my directory .icedove as before, but not also have .thunderbird
Just to be safe, I saved my current .icedove to another folder before running today's e-mail on Thunderbird.

When I ran backup, I used my original script to save .icedove folder to my backup drive, worked great.
Then I made a new backup script to save .thunderbird folder to my backup drive. Got the useless message about rsync skipped a non-regular file .thunderbird

I checked the .thunderbird file and it has the exact same data in it as the .icedove
However, it appears there is a Symlink joining these two files. I don't know how to tell if this is true, but I'm sure it is.

My question is this. If I delete the .icedove hidden file, with this break the Symlink so I can then begin using .thunderbird to run a backup from, or is there other settings or scripts I have to worry about that might mess things up?

What I'm thinking is, what files I see in .thunderbird are not really there, and I'm actually looking at .icedove when I open .thunderbird

I did look on-line, but whatever they are talking about is way over my head, other than I did learn the two files are Symlinked together. But what that means exactly I don't really know. If I right click and select properties on .thunderbird, it shows the same size file as .icedove, but not if the data is really there or not. I DO KNOW the new profile data is in .thunderbird but that's all I know.

Re: Automatically added Symlinks removal?

Posted: 15 Oct 2017, 16:18
by yogi
I'll begin by saying that I do not use Thunderbird in any of my Linux machines. That means I do not have any first hand experience with it outside of Windows, but, as usual, that won't stop me from making up some explanation. :mrgreen:

A "symlink" is the short way of saying symbolic link. I've run across and used such things in my programming days, but to be honest I never saw the need or sense to using them. Then again, I wasn't a great programmer either. A coder would tell you that a 'simlink' is a method of indirect addressing. Quite often data, like the template for this web page, is stored in a block of dedicated memory. The starting address of that memory block is typically placed in a stack of similar addresses. Thus, you can switch between pages rather quickly by looking up the address in the stack and going directly to the memory block with the template. When you have a lot of tabs open in your browser, for example, you do not load them from the server each time you switch tabs. You get the tab address from the stack and that displays what is in the memory block. So, the addresses stored in the stack are links, symbolic links. They are symbolic because they have no data other than the starting address of a memory block.

How this applies to IceDove and Thunderbird is a mystery to me, but I can make an educated guess. The mail client profile is stored in a block of memory, just like those web pages from my example. The beginning address of that profile memory block is in the symbolic link byte of memory. Thus you can call the profile from either program by simply looking up the symlink.

My question as a programmer is, "why bother?" If the memory location for the profile is known, why not just go there without flipping through the stack of addresses in queue? Well, I think the answer is that the block of memory with the data changes but the symbolic link address (not its contents) does not. Thus the programmer is not burdened with keeping track of where in memory the needed data is located. All s/he has to do is indirectly address it via the program address stack.

Anyway, I hope you get the basic idea. Since I'm not sure what IceDove or Thunderbird is doing on your machine, it will be hard for me to say that the symlink can be broken. You may do what you said and simply remove the dot-file(s). When you start up Thunderbird (or IceDove) it will make a new profile for you with default values. I would guess that however that symlink was generated in the first place is part of the software for the mail client, thus you won't be able to separate the two unless you stop using one of the two programs. You might be able to use a text editor and look at what is inside those dot-files. Then again, it may all be binary and unreadable. I have fixed a few problems with Mozilla by removing it's profile/database and forcing it to create a new one. Plus, I know IE or Edge can steal the data from my Mozilla based browser, which tells me it's all in a block of memory that most likely has a symbolic link to those other browsers.

Re: Automatically added Symlinks removal?

Posted: 16 Oct 2017, 14:25
by Kellemora
Thanks Yogi

I tried doing a direct copy of the .thunderbird hidden folder, the only thing that appeared in the new folder were the files associated with Thunderbird. At least now I know my huge e-mail file is not taking up twice the amount of space, hi hi...

I used Eudora for many years. It was taken over by Thunderbird, which was not exactly like how Eudora worked, but close.
Then there was a legal issue of some sort and they changed the name to IceDove, but it was still Thunderbird.
At that time, I had to load IceDove from Synaptic, then make a copy of my .thunderbird hidden folder, and copy only the mail file over to the .icedove folder. Worked great ever since.
But now that they went back to Thunderbird, Thunderbird created its own .thunderbird file, and I see now the e-mail file itself is still in .icedove and only a symlink in .thunderbird to see it. This of course makes it appear the files are in .thunderbird and they are not. More things to have to remember when I set up another computer and move my e-mail to it.

They have made a LOT of changes in Debian 9.2!
I just went to the character map, which used to be massive, showed each font I have installed, and all the unicode codepoint numbers for each character.
The new one is super tiny and has very little in it. Leastwise nothing I would use much.

Today I needed a cursive four for something. I've used a cursive four many times. But now it is no longer in any of the new fonts. Won't do me any good to use it if no one else can see it. The unicode for a cursive four used to be only four digits long, now it is five digits long, so is not recognizable by most computers. It is U-109C3 now. Which will just print a box showing the code, like this 𐧃, well here it may just show an empty rectangle.

Have a great day Yogi!

Re: Automatically added Symlinks removal?

Posted: 16 Oct 2017, 15:55
by yogi
I used Eudora on my Windows 98 machine. Somewhere about the time Win98 died, Eudora was bought out by another company which was not Thunderbird nor Mozilla related. The new company said they are now selling the program, but since I was a long time Eudora customer they gave me a free license. It didn't work the same and I was very disappointed. I used web mail until Mozilla resurrected itself and created an e-mail client, i.e. Thunderbird. It was a dog to configure but worked very well after that. Periodically I back up the .msf (mail content) files which proved to be a life saver a time or two. They are easy to read with third party software via Windows. Not sure how easy it would be for Debian. The mail files are in a directory of their own and I suspect any program capable of reading them can link to the proper directory. The only problem I see would be if I uninstalled the program that created the files in the first place. Would it take the .msf files with it and thus crash both programs? If it did, I guess that would be the downside of symbolic links.

Re: Automatically added Symlinks removal?

Posted: 18 Oct 2017, 13:22
by Kellemora
Hmm. I responded to this yesterday.
I've noticed since the upgrade, after I hit submit, it may not go out, and I find a second submit button, if I catch it.

I probably said something about stopping using proprietary programs because they do not have a generic output to save stuff to, that is readable.
All of my old Eudora files were converted to text files, and Thunderbird files can be read with Gedit OK if need be.

I had hundreds of drawings I made in Auto-Sketch, the dumbed down version of Auto-CAD. The only way I could keep them is if I exported them as an image file, aka a picture. So they were technically useless after that. Can't zoom in on an image the way you can on Auto-CAD, hi hi...

I did learn I can create a new Thunderbird file, then copy my e-mail file over to it, and it will be like before, no symlinks.

I forget whatever else I may have said.
Have a great day Yogi!