Tilde files

[Keith]

Before modifying an Ubuntu system file recently (mimeapps.list), I saved a backup copy first.  Upon bravely using my new-found Unix skills to remove the backup once everything was working, I found another copy of the original (and hence backup) file with the “~” symbol appended (mimeapps.list~). 
Can anyone explain the reason for its presence, before I delete it?

[Mark Greaves (PCNetSpec)]

You probably have gedit set to save a backup copy of changed files before saving .. in which case gedit saves a file called original_filen ame~ as a backup.

Point is I had no way of knowing if you had gedit set to do this, so erred on the side of caution .. better to have two backups than none


You can change this setting in gedit if you wish .. it's in the gedit preferences.

[Keith]

Ah, yes - it was my first use of gedit and you are right. 
I think I'll leave it like that as I can screw up anything!
My thanks, as usual.

[Tony Norton]

Don't know if this is relevant to Unix, but in Windows a tilde, usually precedes the filename in Windows, is an indicator that the file is open and stops another user on the terminal or network from altering the file. If you have a program crash the tilde file will remain on the system and needs to be deleted before you can further modify the original file.

Tony N

[Mark Greaves (PCNetSpec)]

Yeh, some applications in Linux do something similar .. take LibreOffice for example, if you open a file called mydoc.odt it will create a hidden lock file in the same directory called .~lock.mydoc.odt# (where the "." at the beginning makes it a hidden file) .. to stop it being edited by others.

Meanwhile if any changes are made to the document, and you have Autorecovery enabled, a backup will be created at ~/.config/libreoffice/3/user/backup/Untitled 1.odt_0.odt .. the number in red will count up in increments every time it is autosaved.

LibreOffice also supports versioning.

As in Windows .. only certain apps do this


But the files Keith was referring to were backups made by gedit .. where it creates a backup with a tilde suffix when you save a file .. it's a backup, not a lock or even a recovery, as it doesn't lock the file and if the machine went down before you saved changes, the backup wouldn't be created.

[Keith]

Thank you, gents - I learn something every day.  Sadly, I rarely remember it.