Re: Monitor mode handling (bug ?)

[Steffen Nurpmeso <steffen@xxxxxxxxxx>]

Ganael Laplanche wrote in
 <3939408.BRNeRiNLvY@xxxxxxxxxxxxxxxxx>:
 |On Wednesday, January 11, 2023 5:25:10 PM CET Ganael Laplanche wrote:
 |
 |> This is exactly what I use fpsync for (to get a new process group). Do I
 |> understand that this feature is not available in Dash ?
 |
 |I'll rephrase : this is exactly what I use *for* fpsync (to get a new \
 |process 
 |group for each sub-job). Do I understand that this feature is not availa\
 |ble in 
 |Dash ?

Just to note that shells may have problems with monitor mode
(especially scripted, non-interactive).  This was a problem when
writing a scaling multi-processed test script.  I now do

        [ -n "${JOBMON}" ] && set -m >/dev/null 2>&1
        ( # Place the job in its own directory to ease file management
                trap '' EXIT HUP INT QUIT TERM USR1 USR2
                JOB_MSG_ID=
                ${mkdir} t.${JOBS}.d && cd t.${JOBS}.d &&
                        eval t_${1} ${JOBS} ${1} &&
                        ${rm} -f ../t.${JOBS}.id
        ) > t.${JOBS}.io </dev/null & # 2>&1 </dev/null &
        i=${!}
        [ -n "${JOBMON}" ] && set +m >/dev/null 2>&1
        JOBLIST="${JOBLIST} ${i}"

This is a problem if $JOBMON=, as unfortunately it may leave
zombie processes running.  Luckily all {,/usr/xpg4}/bin/sh'ells do
this well, including dash.

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)