Re: defuncted printf process when using wpa_supplicant

[Alex fxmbsw7 Ratchev]

On Wed, Mar 30, 2022, 16:15 Chet Ramey <chet.ramey@case.edu> wrote:

> On 3/30/22 1:40 AM, Alex fxmbsw7 Ratchev wrote:
> > i do
> >
> > wpa_supplicant -i"$if" -c<( printf %s\\n \
> > 'network={' "ssid=\"$ssid\"" "psk=\"$pass\"" '}'
> > ) &
> > { sleep 3 ; dhclient "$if" ; } &
> >
> > which is simply wpa_supplicant -iiface -c<( conf file printing )
> >
> > it since years resuts in such : i think before it said printf defuncted
>
> Since printf is a shell builtin, there's no way for ps to reliably
> determine the name of the command in the process substitution.
>
> > root      1530  0.0  0.0      0     0 ?        Z    07:19   0:00  \_
> > [3.wpa] <defunct>
>
> Since the command is asynchronous, the shell forks and does word expansion
> in the subshell, at which point it creates the pipes for the process
> substitution. It then suppresses any additional forks and simply execs the
> sleep process. The shell started to run the process substitution sits there
> peacefully, not consuming any resources, until wpa_supplicant exits and
> everything gets reaped by init/systemd/whatever.
>

cool mate i halfway understand but great peaceful explaintion :)

-- 
> ``The lyf so short, the craft so long to lerne.'' - Chaucer
>                  ``Ars longa, vita brevis'' - Hippocrates
> Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/
>