This is on MacOS Sequoia.
Several years ago, I created in the course of a backup process run by rsync, a file on an external hard disk:
ls -l /Volumes/V200GB_A/imac_save/Library/Containers/com.coteditor.CotEditor/Data/Library/Autosave\ Information/0F338E6B-512C-4998-A941-41B770B4351D.genstore.noindex/7F5BDCD7-2D3E-4CC1-9628-BDC6CB369986.html
shows:
-r-xr-xr-x 1 ronaldfischer staff 6538 Jan 14 2022 /Volumes/V200GB_A/imac_save/Library/Containers/com.coteditor.CotEditor/Data/Library/Autosave Information/0F338E6B-512C-4998-A941-41B770B4351D.genstore.noindex/7F5BDCD7-2D3E-4CC1-9628-BDC6CB369986.html
I am the owner, and also in the right group: The command id shows
uid=501(ronaldfischer) gid=20(staff) groups=20(staff),12(everyone),61(localaccounts),79(_appserverusr),80(admin),81(_appserveradm),98(_lpadmin),701(com.apple.sharepoint.group.1),702(com.apple.sharepoint.group.2),33(_appstore),100(_lpoperator),204(_developer),250(_analyticsusers),395(com.apple.access_ftp),398(com.apple.access_screensharing),399(com.apple.access_ssh),400(com.apple.access_remote_ae),703(com.apple.sharepoint.group.3)
But when I try to remove the file with
rm -f /Volumes/V200GB_A/imac_save/Library/Containers/com.coteditor.CotEditor/Data/Library/Autosave\ Information/0F338E6B-512C-4998-A941-41B770B4351D.genstore.noindex/7F5BDCD7-2D3E-4CC1-9628-BDC6CB369986.html
I get the error message:
rm: /Volumes/V200GB_A/imac_save/Library/Containers/com.coteditor.CotEditor/Data/Library/Autosave Information/0F338E6B-512C-4998-A941-41B770B4351D.genstore.noindex/7F5BDCD7-2D3E-4CC1-9628-BDC6CB369986.html: Permission denied
Is there some mysterious Apple protection mechanism in the way?
Note: The majority of the files on that disk can be deleted. There is just a couple of them which refuse deletion.
UPDATE
Based on the comment by bmike, I include here more information of that file:
> ls -led /Volumes/V200GB_A/imac_save/Library/Containers/com.coteditor.CotEditor/Data/Library/Autosave\ Information/0F338E6B-512C-4998-A941-41B770B4351D.genstore.noindex/7F5BDCD7-2D3E-4CC1-9628-BDC6CB369986.html
-r-xr-xr-x 1 ronaldfischer staff 6538 Jan 14 2022 /Volumes/V200GB_A/imac_save/Library/Containers/com.coteditor.CotEditor/Data/Library/Autosave Information/0F338E6B-512C-4998-A941-41B770B4351D.genstore.noindex/7F5BDCD7-2D3E-4CC1-9628-BDC6CB369986.html
> ls -lO /Volumes/V200GB_A/imac_save/Library/Containers/com.coteditor.CotEditor/Data/Library/Autosave\ Information/0F338E6B-512C-4998-A941-41B770B4351D.genstore.noindex/7F5BDCD7-2D3E-4CC1-9628-BDC6CB369986.html
-r-xr-xr-x 1 ronaldfischer staff - 6538 Jan 14 2022 /Volumes/V200GB_A/imac_save/Library/Containers/com.coteditor.CotEditor/Data/Library/Autosave Information/0F338E6B-512C-4998-A941-41B770B4351D.genstore.noindex/7F5BDCD7-2D3E-4CC1-9628-BDC6CB369986.html
I also did a
xattr /Volumes/V200GB_A/imac_save/Library/Containers/com.coteditor.CotEditor/Data/Library/Autosave\ Information/0F338E6B-512C-4998-A941-41B770B4351D.genstore.noindex/7F5BDCD7-2D3E-4CC1-9628-BDC6CB369986.html
but the output was empty.
In case it matters: The file system on the volume is shown as “Mac OS Extended (Case-sensitive, Journaled)”.
UPDATE
Adding information about the containing folder:
> ls -lOd /Volumes/V200GB_A/imac_save/Library/Containers/com.coteditor.CotEditor/Data/Library/Autosave\ Information/0F338E6B-512C-4998-A941-41B770B4351D.genstore.noindex/
dr-x------ 3 ronaldfischer staff - 170 Jan 14 2022 /Volumes/V200GB_A/imac_save/Library/Containers/com.coteditor.CotEditor/Data/Library/Autosave Information/0F338E6B-512C-4998-A941-41B770B4351D.genstore.noindex/
