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I have just run into the case in which the owner-group of a file has more permissions than the owner-user of a file.
user1@pc:/tmp$ ls testfile -l ----rw---- 1 user1 user1 9 Okt 16 13:16 testfile
Since the user
user1 has no permissions to to read the file I get this
user1@pc:/tmp$ cat testfile cat: testfile: Permission denied
This suprised me as
user1 is member of the group
user1 which has permission to read the file.
Interesstingly when doing this:
root@pc:/tmp$ addgroup user2 user1 Adding user `test' to group `ress' ... Adding user test to group ress Done. root@pc:/tmp$ su user2 user2@pc:/tmp$ cat testfile content of testfile user2@pc:/tmp$
I can read
It seesms the permissions granded (or not) on the user-owner level take precedence over anything later like the permissions existing due to group membership.
My question is if there is a reference to this behaviour I experience in my linux system (that is that not having user-permissions takes away group-permissions)
Also is there a use case for this behaviour?