Bug#1024811: linux: /proc/[pid]/stat unparsable

[Thorsten Glaser <tg@debian.org>]

Dixi quod…

>The effect is that /proc/[pid]/stat cannot be parsed the way it is
>documented, as it does not escape embedded whitespace characters;

… nor parenthesēs:

tglase@x61w:~ $ ./mk\)sh -c 'echo $$; sleep 10' &
[1] 13375
tglase@x61w:~ $ 13375
tglase@x61w:~ $ cat /proc/13375/stat
13375 (mk)sh) S 13330 13375 13330 34837 13377 4194304 124 0 0 0 0 0 0 0 20 0 1 0 59029474 2977792 180 18446744073709551615 94911056490496 94911056739789 140721459110048 0 0 0 0 0 134307847 0 0 0 17 1 0 0 0 0 0 94911056765744 94911056773808 94911059955712 140721459115917 140721459115946 140721459115946 140721459118064 0

This is… sad — extremely so. It does not escape anything.
I found proc_task_name(), which has an escape parameter,
which is set to false here, but it’s only for /status
which must escape newlines.

It’s used with false in /stat and /comm… the latter indeed
needing no escapes.

I’d argue that it needs a tristate argument, 0 for /comm
to not escape anything, 1 for /status to escape newlines,
and 2 for /stat to escape whitespace (and perhaps also a
closing parenthesis, using \x29, so splitting both using
scanf as indicated in the manpage and using parenthesēs
as people seem to do on the ’net is fixed).

bye,
//mirabilos
-- 
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