[PATCH] vars.sh: remove unnecessary fork to speedup boot/upgrades

[Thorsten Glaser]

On Mon, 31 Aug 2020, Trek wrote:

> -    for ARG in $(cat /proc/cmdline); do
> +    read -r cmdline </proc/cmdline

Please keep using cat for Linux procfs; reading it from the
shell is broken for many entries (/proc/cmdline isn’t one of
them, but others are:

	https://bugzilla.kernel.org/show_bug.cgi?id=209031

Furthermore, read is slower because it has to read byte for
byte, whereas cat can read in larger blocks. The fork is not
nice but at least one of the shells eligible for /bin/sh has
cat as builtin, so there’s that.

Looking at the script, there’s no way to avoid at least one
fork while sticking to portable /bin/sh due to the mentioned
Linux kernel bug. Sorry.

bye,
//mirabilos
-- 
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