(cache)How to allow everyone to set the last modified time of a file?

exerceo · Today, 10:10 AM

cp -p allows preserving date and time stamps and touch has some parameters to set a custom last modified time (mtime).

But normally, in Linux (and Android by extension), only a file owner can set a custom date and time.

Is there a way to give everyone the ability to set a custom date and time of a file?

jmccue · Today, 10:24 AM

I have not used this on Linux, but I have used it on AIX. I believe Linux does have this ability, depending on distro and file system.

https://wiki.archlinux.org/title/Extended_attributes

I am rather sure there is a way of doing that under Linux. You need to use attributes to give specific users write access to the file. Maybe you can use it to prevent deletion too.

lvm_ · Today, 10:28 AM

[dumb post deleted]

mjolnir · Today, 11:21 AM

Caveat: This worked in bash, WSL2, as 'root.' You might have to play with it to get it to work with 'user.' There may also be security risks involved.
Install the acl package and verify with setfacl --version.
Apply write permissions to a test file:bash

Code:

setfacl -m o:rw /mnt/c/Users/Mjolnir/Downloads/Test/Archive_7zs/example.txt

Test mtime modification as a non-owner user:bash

Code:

touch -t 202510051200 /mnt/c/Users/Mjolnir/Downloads/Test/Archive_7zs/example.txt