Protect your Linux files by an accidental deletion

November 7th, 2008 by T4L

You can protect your most important files from accidental deletion by giving them a “sticky bit” attribute: chmod +t filename

T4L ;

syphus
November 27th, 2008 at 6:48 pm

That will protect files not owned by you (only from being renamed or deleted), another way to do it that would protect any file (from rename / delete / modification) is:

chattr +i

I think this is specific to ext2/3/4

1
syphus
November 27th, 2008 at 6:50 pm

Actually, sticky bit only works like that on directories, from the man-page:

RESTRICTED DELETION FLAG OR STICKY BIT
The restricted deletion flag or sticky bit is a single bit, whose interpretation depends on the file type. For directories, it prevents unprivileged users from
removing or renaming a file in the directory unless they own the file or the directory; this is called the restricted deletion flag for the directory, and is com?
monly found on world-writable directories like /tmp. For regular files on some older systems, the bit saves the program’s text image on the swap device so it will
load more quickly when run; this is called the sticky bit.

2
Live
May 4th, 2010 at 8:12 am

Or you can do this:

sudo chmod 1755 file_or_folder_name, normally we just type:

sudo chmod 755 file_or_folder_name, but the presence of 1 makes it the same as chmod +t filename as stated above.

Then apply it recursively to the contents of a folder, so finally

sudo chmod -R 1755 file_or_folder_name

3

About