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Other BSD and UNIX/UNIX-like Any other flavour of BSD or UNIX that does not have a section of its own.

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Old 21st April 2016
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Default /var/empty on Linux

Does anyone know what the equivalent of /var/empty is on Linux?

I wrote a program that chroots for security reasons. After initialisation it doesn't need to open any more files or devices, so chrooting to an empty directory would work just fine. On FreeBSD and OpenBSD I have the /var/empty directory for exactly this reason. IIRC it's even protected with the system immutable flag to prevent accidental writes.

On my CentOS 7 machine I have a /var/empty, but that has an (empty) sshd directory in it (?) On Ubuntu 15.04 I don't have a /var/empty at all.

Do I need to create a useless and empty /var/run/myprogram directory? Or is there some equivalent?
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Old 21st April 2016
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My Slackware 14.0 has a /var/empty, with nothing in it. Perhaps none of the installed programs are configured to use it? You could create one if you need it. For chroot-ing I've also created /var/jails with subdirectories for dnscrypt-proxy, mail (sendmail) and named.
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Old 5th June 2017
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Hmm, /dev/null?
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Old 5th June 2017
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This link suggests that /var/empty is a part of most Linux systems too, albeit not defined in the FHS.

The Arch Linux filesystem package also includes /var/empty so it seems to be "supported".

heir(7) in my Arch box notes:
Code:
       /var/tmp
              Like /tmp, this directory holds temporary files stored for an unspecified
              duration.
Perhaps this would be suitable?

EDIT: ha! Necrobump! Sorry...

Last edited by Head_on_a_Stick; 5th June 2017 at 03:08 AM. Reason: excusing my reply to a semi-necrobump.
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Old 9th June 2017
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The thing with chroot-ing it to /var/tmp/ (or /tmp/) is that you don't know which files may be there, and that the chrooting program may accidentally expose information present in those directories, or even worse allow modification of those files!

With /var/empty/, I don't need to worry about any of that.

At any rate, my eventual solution was to create an empty /var/program_name/ directory. I later added some support for file caching, so I had to do that in the long run anyway :-)
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