Some web searching and reading on how linux permissions work and are used would probably be better than my explaining it here.
But in brief:
It gets complicated when using non Linux filesystems (e.g. FAT, exFAT, NTFS). Most of those have no support* for Lionux sytle owner, group, and permissions so what you see in the filemanager (or in ls -l) is a fiction created in the drive. This fiction is usually the same for every file and directory on the drive/partition, set at the time the drive/partition is mounted, and cannot be changed.**
I can't comment on the videos and guides you've used as you didn't link to them but on the face of it they likely the usual thirdhand "it'll just work" variety.
[shameless self promotion]
For more on getting stuff mounted with the correct permissions and at system boot have a look at Using fstab A Beginner's Guide
[/shameless self promotion]
*: i.e. the data is not present and cannot be added to the data on disc.
**: at least not with the usual tools. It can often be changed by unmounting and remounting with different optiond but impact every file and directory too.
But in brief:
- Linux is multi-user from the ground up
- Each file and directory has an owner and a group.
- It also has three sets of permissions: a set for the owner, a set for members of its group, and a set for everyone else.
- When you attempt to do anything to a file or directory your user ID and group ID is used to determine which set of permissions apply and these are checked for what you are allowed to do. For some actions on files directory permissions are checked too (as these actions modify data on the directory too).
It gets complicated when using non Linux filesystems (e.g. FAT, exFAT, NTFS). Most of those have no support* for Lionux sytle owner, group, and permissions so what you see in the filemanager (or in ls -l) is a fiction created in the drive. This fiction is usually the same for every file and directory on the drive/partition, set at the time the drive/partition is mounted, and cannot be changed.**
I can't comment on the videos and guides you've used as you didn't link to them but on the face of it they likely the usual thirdhand "it'll just work" variety.
[shameless self promotion]
For more on getting stuff mounted with the correct permissions and at system boot have a look at Using fstab A Beginner's Guide
[/shameless self promotion]
*: i.e. the data is not present and cannot be added to the data on disc.
**: at least not with the usual tools. It can often be changed by unmounting and remounting with different optiond but impact every file and directory too.
Statistics: Posted by thagrol — Tue Apr 16, 2024 11:20 pm