Where to save stuff (in snap-agnostic way)

[Luca Dionisi]

Well, it seems that the problem is the userspace tool itself.
bash-4.3$ mkfifo --help
bash: /usr/bin/mkfifo: Permission denied

On Sat, Feb 4, 2017 at 12:00 PM, Luca Dionisi <luca.dionisi at gmail.com> wrote:
> On Sat, Feb 4, 2017 at 11:43 AM, Oliver Grawert <ogra at ubuntu.com> wrote:
>> hi,
>> Am Freitag, den 03.02.2017, 21:04 +0100 schrieb Luca Dionisi:
>>> What is the best place to write (and read) a temporary FIFO file from
>>> a confined snap application?
>>> This is for simple IPC between 2 processes of the same snap.
>>> Before attempting to snap the application I was using a fixed
>>> filename
>>> in /tmp. Admittedly poor solution.
>>> The solution should be usable also with another packaging system.
>>>
>> well ... in case of snaps /tmp is a private directory that only your
>> snap can access so it is actually a good place for such stuff ...
>
> It's worse than that, Jim!
>
> Inside the snap environment I can write files and directories both in
> /tmp and in $XDG_RUNTIME_DIR.
> What I cannot do anywhere is create a FIFO.
>
> bash-4.3$ mkfifo a
> bash: /usr/bin/mkfifo: Permission denied
>
> What's the problem here?
>
> To be honest I should say that my tests have been conducted in LXD
> containers. I don't know if the situation holds true also in real
> machines.