[Buildroot] bash: /dev/fd/62: No such file or directory
joerg.krause at embedded.rocks
Thu Mar 29 19:46:27 UTC 2018
On Fri, 2018-03-16 at 15:19 +0100, Peter Korsgaard wrote:
> > > > > > "Jörg" == Jörg Krause <joerg.krause at embedded.rocks> writes:
> > Hi,
> > I am facing an issue with busybox init system, bash and mdev. When a
> > bash script uses process substitution, bash ends with an error:
> > """
> > # bash -c 'read x< <(echo 1); echo $x'
> > bash: /dev/fd/62: No such file or directory
> > """
> > The issue is addressed is some threads, e.g. . The problem is that
> > /dev/fd does not exist when using mdev:
> So that is really strictly seen a bug in bash. The /dev/fd convenience
> symlink is afaik a convention from udev/systemd.
> But OK, bash might not be alone and the pragmatic solution would indeed
> be to create these symlinks ourselves in the busybox and sysvinit
> inittabs, similar to how we create /dev/pts and /dev/shm.
> It is only really needed if (e)udev isn't used, but it doesn't really
> hurt to create them even if eudev will recreate them afterwards.
> Keep in mind that we still support a static /dev, so we should also add
> them to system/device_table_dev.txt and redirect errors to /dev/null so
> you don't get a bunch of warnings about these symlinks when booting with
> a static /dev.
I am trying to get this working. I managed to add the entries to
inittab for busybox and sysvinit, but I am unsure how to add those
symlinks to the static /dev. makedevs does not support symbolic links.
> Notice that it isn't only about /dev/fd. From
> static const char symlinks =
> "-/proc/kcore\0" "/dev/core\0"
> "/proc/self/fd\0" "/dev/fd\0"
> "/proc/self/fd/0\0" "/dev/stdin\0"
> "/proc/self/fd/1\0" "/dev/stdout\0"
> "/proc/self/fd/2\0" "/dev/stderr\0";
> There is some logic to only create /dev/core if /proc/kcore exists, but
> I think we can just create it unconditionally.
> Care to send patches doing this?
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