[SOLVED] ext4 - permission to create/modify a file without 'delete' permission

BeachHead · 06-07-2014, 01:59 PM

Hallo,
i want to catch a temp file with dynamic name created by a program that is available only for some milliseconds. For this i probably need some permissions like this: Create/modify but no delete.

I can do this with NTFS but on ext4 it seems impossible. Chattr +i +u or setting folder to sticky seems useless. Setting folder to read-only probably works only if the file would already exist (allows 'modification' and 'no deletion' but unfortunately no 'creation').

Any suggestions?

unSpawn · 06-08-2014, 07:31 AM

Quote:

Originally Posted by BeachHead

i want to catch a temp file with dynamic name created by a program that is available only for some milliseconds.

If you mean "catch" as in "log" then you could use the audit service or FUSE LoggedFS or inotify(wait)?

BeachHead · 06-08-2014, 05:01 PM

Quote:

Originally Posted by unSpawn

If you mean "catch" as in "log" then you could use the audit service or FUSE LoggedFS or inotify(wait)?

No, that unfortunately doesn't help. Its a binary file and i'm trying to get it before it gets deleted.

rknichols · 06-08-2014, 08:16 PM

If this is a file that the program creates and immediately deletes while keeping the file open for its own use, you can still access the file via the /proc/{PID}/fd/{FD#} link.

BeachHead · 06-08-2014, 08:34 PM

That works indeed.

What a valuable tip.. Thank you!