1. If you never empty it, it grows and wastes valuable disk space
2. If you empty it frequently, you lose its buffer benefits for recovery. Plus, who likes frequently doing this highly manual task?
3. Finally, if like me, you get bored by this nonsense, you end up permanently bypassing the trash (with systematic Shift+Delete instead of Delete), which is of course very dangerous

Linux users, rejoice! Enter Autotrash. The name may sound a little scary, but this tiny command-line Python application is actually very friendly and fully solves the problems I just exposed. Its humble task is to selectively purge your trash based on certain criteria that you specify, like Deletion date, Remaining disk space, or Regular expressions.

Edit 2010/04/14: Windows users, Martin found a great app for you, read his followup article.

For example, you can tell Autotrash to delete files that have been in the trash for more than 7 days ago, and to ensure that at least 10GB remain available:

This means our three problems are solved:

1. The trash never gets too big
2. It always contains a reasonable recent backlog of deleted items, ready for the occasional recovery
3. Geeks like me can come back to sane Delete practices

The next question you’ll probably ask is: “Great, but I don’t want to have to run Autotrash manually, how do I setup a schedule?”. In typical GNU style, Autotrash doesn’t do that, and it’s okay because it’s not its job. To do the scheduling, I suggest that:

• Either you setup a cron task running every n hours
• Or, if you are as lazy as I am, you can simply add Autotrash to the Startup programs:
  
  In my case, I generally shut down my computer for the night, so launching Autotrash at startup is a satisfying “good enough” tradeoff.

The most straightforward way to install Autotrash on an Ubuntu machine is to use its PPA. Inside a terminal, enter:
sudo add-apt-repository ppa:bneijt/ppa && sudo apt-get update && sudo apt-get install autotrash

Once the installation is done, open the manual page to see what it can do, and do your own setup:
man autotrash

Autotrash is free software licensed under the GPLv3, currently available as source or Ubuntu PPA. Special thanks to nekohayo who made me discover it.

Ronan is a geek and musician living in Montreal. He enjoys days when his hard drive doesn’t evaporate because of an accidental keystroke and rambles about software, music and life at flying molehill.

Such is the case with removing files. There are two fundamental ways to remove a file:

With the help of a GUI such as Thunar, Dolphin, or Nautilus

With the help of a command such as rm or shred.

In this article we will primarily examine the latter and touch on the former.

The former – GUI

As you would expect, in all three of the graphical file managers you can easily remove a file simply by right clicking the file and selecting Delete. There are, however, some subtle differences. You will notice, in both Dolphin and Nautilus you can choose between Deleting a file and moving a file to the Trash. This behavior mimics that of Windows Explorer. Once you move a file to the Trash it will remain there until you empty your trash. Should you select to actually Delete the file, however, that file is deleted right away.

This behavior is not available in Thunar. With Thunar you can keep it or delete it.

rm that file

The basic remove command is rm. It is used like this:

rm OPTIONS

Believe it or not there are options to go along with the rm command. There are two options that are used most often:

f – This option will force the delete. In other words you will not have to answer “y” to every file you want to delete. This is very handy when you are deleted a directory.

r – This option will recursively delete all files within a directory as well as the directory itself.

As you can surmise, the r and f options are most often used together. So to delete the ~/TEST directory and all of its files you would issue the command:

rm -rf ~/TEST

If you only wanted to delete the file test.txt within the ~/TEST directory you would issue the command:

rm ~/TEST/test.txt

What if you wanted to delete all jpg files within the ~/TEST directory? Simple:

rm -f ~/TEST/*.jpg

The * character is a wild card which means, in this case, anything that ends with .jpg. Notice the “.”. If you leave that out you can delete any file ending in jpg – not just any file with the extension .jpg.

shredd’ing a file

The shred command is a whole different beast. Shred is for the paranoid. Shred completely obliviates a file by overwriting its contents. Instead of deleting a file shred will simply overwrite a file and the end results will be an unreadable binary file that can then be safely removed.

And no matter how paranoid you are, shred will help you out. You can declare how many overwrite iterations shred will perform. You can even add a final overwrite of nothing but zeros to hide the fact that you ever shredded a file. And finally, you can also add a switch to inform shred to automatically remove the file after the iterations.

Shred is used like so:

shred OPTIONS filename

The most popular options are:

v – Show progress.

z – Add final overwrite of zeros.

u – Remove file after iterations

n – Overwrites n times

So to shred a file by iterating 10 times, followed by a final iteration of zeros, and then deleting the file upon completion you would issue the command:

shred -v -n 10 -z  FILENAME -u

Where FILENAME is the actual file name.

After that command your removed file has vanished into thin air.

Final thoughts

Many different routes to the same destination. Of this, Linux is the master. In the case of removing files, you can send it to the trash for possible later easy retrieval, remove it with the possibility of a much more difficult retrieval, or shred it with no hopes of retrieval. Your call.

Open the Thunderbird Application Data folder which is located in your document and settings folder in Windows. Select the appropriate Thunderbird profile if there is more than one and click on Mail in that profile. You get a listing of all your email addresses. If you setup Firefox to have different mail folders for every email address you have to click in the folder of the email address that received (or send) the message. Otherwise Local Folders is the way to go.

The important files are those without extensions (Trash, Sent, Inbox ..) – locate the one that contained the mail(s) that you have deleted or are corrupted (do not show up anymore). Open it in an text editor, you could use notepad2 for instance for this purpose. Some folders might be rather big so choose a text editor that can handle large files. Thunderbird should be closed completely while editing those files.

All mails are basically stored in that file. The important part for us are the lines X-Mozilla-Status which defines a certain state of a message such as Read, Unread or Deleted. Search for the message(s) that you want to recover and edit the X-Mozilla-Status: XXXX line into X-Mozilla-Status: 0000 for unread or X-Mozilla-Status: 0001 for read messages.

Recovered messages will appear at the bottom of the folder and should be there after you startup Thunderbird for the next time. You sometimes have to delete the .msf file to make this work. If you edited the file Trash you would delete the file Trash.msf afterwards if the mails do not re-appear after a new start of Thunderbird.

source (and additional information)