Re: [9fans] Novice question - run as other

[David Tolpin <dvd@davidashen.net>]

>
> >@{echo -n none > '#c/user' ; while() {sleep 1} }
>
> >succeeds but does not change the owner of the process. Why?
>
> well, seems it would be bad if all you had to do to change userid was 
> echo into '#c/user'
>
> So, starting from that, the why should be apparent.

The 'Why' was about a different issue.

The question was why the C program behaves differently than
the shell script.  The C program just writes to #c/user to
change the owner of the process.

The answer is that writing to #c/user is special
in the sense that although it is a part of namespace, it changes
the state of the process space, which is only apparent if you look
into the kernel source.

A more general conclusion is that for tasks where writing to
or reading from files reflects or affects process space, and not
name space, rc is not suitable and C code must be written.

I am now into the sources to understand which files in the namespace
are actually not in it, but in the process space.

David Tolpin
http://davidashen.net/