Two files with exact same permissions, but one is opening read-only

Ben Hocking

4/4/24, 5:22 PM

On an Ubuntu 22.04 VM, when I look at my files, I see that they have read/write/execute permissions set up correctly for root and vboxsf:

$ ls -lrt foo.pvs bar.pvs
-rwxrwx--- 1 root vboxsf 23492 Jan 24 12:08 foo.pvs
-rwxrwx--- 1 root vboxsf  1328 Apr  4 09:50 bar.pvs

The user (me) is set up as a member of the group vboxsf. However, when I load the two files up in emacs, they act differently. The first file (which I'm calling foo.pvs here, but that's not its real name) works just fine, but the second file (which I'm calling bar.pvs) opens up as read-only for some reason. Is there some hidden setting somewhere else in Ubuntu (or VirtualBox) that is affecting this? If it matters, this is on a mounted folder with a Windows 11 host.

Additional fact I figured out while writing this question: when I open bar.pvs up using vi, it's not read-only. Making a change and saving it out, however, doesn't change the status in emacs. I need to open the file in emacs, because I'm really opening the file up in pvs (SRI's Prototype Verification System), which is a skin around emacs.

1 + 1

virtualbox

emacs

read-only

user68186

4/4/24, 5:26 PM

Please add the OS and version number to your question.

Score:0

Ubuntu

Ben Hocking

4/4/24, 5:32 PM

Short answer: delete the hidden file .#bar.pvs

As I was trying to add more detail to my question, I gathered the information I needed to figure it out.

When doing an ls -lart, I found a hidden file called .#bar.pvs file, but there was no .#foo.pvs. When I tried to delete this file, I couldn't do it from within Ubuntu (at least not easily, not even using sudo), so I deleted it from within Windows. From what I can tell, it seems the .#bar.pvs file was created when I was editing the file in PVS, but the system crashed while it was open and so it wasn't properly removed upon exit.

After doing so, opening it up in emacs no longer set the file to read-only.

+ 4

Hannu

4/4/24, 6:30 PM

`$ sudo rm '.#bar.pvs'`

David

4/5/24, 6:26 AM

@Hannu This needs some context.

Ben Hocking

4/5/24, 12:26 PM

I believe what Hannu is suggesting is that I could've used `sudo` to `rm` the files. Alas, due to the underlying Windows file system managing things, that was not the case.

Hannu

4/5/24, 7:02 PM

Yes that was a quickie to indicate exactly that, if the VM cannot handle it's own files, then that is a bug.

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Two files with exact same permissions, but one is opening read-only

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