Re: [PATCH] Making --fg return the exit code of the command

[Samuel Thibault]

Ping?

Samuel Thibault, le dim. 13 févr. 2022 16:44:55 +0100, a ecrit:
> Ping?
> 
> Samuel
> 
> Samuel Thibault, le dim. 30 janv. 2022 16:52:56 +0100, a ecrit:
> > Hello,
> > 
> > GNU parallel is doing almost exactly what I need, except that it does
> > not return the exit code of the command, but rather only 0/1.
> > 
> > 
> > Basically the kind of thing I am after is this kind of thing:
> > 
> > for algo in algo1 algo2 algo3
> > do
> >     for size in $(seq 1 10)
> >     do
> >             (
> >                     TEST=${algo}_${size}
> >                     sem --fg -j $J ./run_test $TEST
> >                     RET=$?
> >                     if [ $RET = 77 ] ; then
> >                             echo "$TEST" skipped
> >                     elif [ $RET = 0 ] ; then
> >                             echo "$TEST" succeeded
> >                     else
> >                             echo "$TEST" failed
> >                     fi
> >                     exit $RET
> >             ) &
> >     done
> > done
> > 
> > RESULT=0
> > while true
> > do
> >     wait -n
> >     RET=$?
> >     if [ $RET = 127 ]; then break; fi
> >     if [ $RET != 0 -a $RET != 77 ]; then RESULT=1 ; fi
> > done
> > 
> > exit $RESULT
> > 
> > And several of these are getting run in parallel etc. so it's a
> > parallelism mess. Using parallel --semaphore nicely allows to let all of
> > these use a given level of parallelism.
> > 
> > 
> > I know that parallel has functionalities to gather results etc. but the
> > example above is just a very simplified case of what I need (various
> > levels of loops, different levels of "I want to know whether this set of
> > runs failed or not", etc.), and as is shown we want to handle 77 (skip)
> > specially, so I need to keep the general shape of the code and not rely
> > on parallel for that part.
> > 
> > It happens that the only thing I currently miss is that I never get 77,
> > parallel --semaphore --fg always turns it into 1.
> > 
> > And it happens that it seems to be easy to get that behavior, see the
> > attached patch. The idea is that when using --fg, the situation is
> > similar to --halt now,fail=1: we have just one job to report the result
> > of, so we can just return its exit code. I added an --fg-exit option to
> > do that.
> > 
> > I would even argue that this should be the default of --fg:
> > parallel_tutorial says itself: “The difference between this [sem
> > --fg] and just running the command, is that a mutex is set, so if other
> > @strong{sem}s were running in the background only one would run at a
> > time.”  While reading that I was assuming that sem --fg would just
> > return the exit code of the command and was very surprised to see that
> > it does not. So we could even simplify my patch into not introducing an
> > fg-exit option, and just test for $opt::fg.
> > 
> > Put another way,
> > 
> > sem --fg exit 42
> > 
> > should return 42, not 1.
> > 
> > With regards,
> > Samuel
> 
> > diff --git a/src/parallel b/src/parallel
> > index 9ea69033..b6306cbd 100755
> > --- a/src/parallel
> > +++ b/src/parallel
> > @@ -115,7 +115,10 @@ sub halt() {
> >     }
> >     wait_and_exit($Global::halt_exitstatus);
> >      } else {
> > -   wait_and_exit(min(undef_as_zero($Global::exitstatus),101));
> > +   if(not defined $Global::halt_exitstatus) {
> > +       wait_and_exit(min(undef_as_zero($Global::exitstatus),101));
> > +   }
> > +   wait_and_exit($Global::halt_exitstatus);
> >      }
> >  }
> >  
> > @@ -1696,6 +1699,7 @@ sub options_hash() {
> >      "semaphoretimeout|st=s" => \$opt::semaphoretimeout,
> >      "semaphorename|id=s" => \$opt::semaphorename,
> >      "fg" => \$opt::fg,
> > +    "fg-exit" => \$opt::fg_exit,
> >      "bg" => \$opt::bg,
> >      "wait" => \$opt::wait,
> >      # Shebang #!/usr/bin/parallel --shebang
> > @@ -11101,6 +11105,14 @@ sub set_exitsignal($$) {
> >         $limit = $Global::total_completed;
> >     }
> >     if(not defined $limit) {
> > +       if($opt::fg and $opt::fg_exit and not defined 
> > $Global::halt_exitstatus) {
> > +           # --fg-exit
> > +           # Emulate Bash's +128 if there is a signal
> > +           $Global::halt_exitstatus =
> > +               ($job->exitstatus()
> > +                or
> > +                $job->exitsignal() ? $job->exitsignal() + 129 : 0);
> > +       }
> >         return ""
> >     }
> >     #  --halt # => 1..100 (number of jobs failed, 101 means > 100)
> > diff --git a/src/parallel.pod b/src/parallel.pod
> > index 2e2c6424..0bac31c8 100644
> > --- a/src/parallel.pod
> > +++ b/src/parallel.pod
> > @@ -908,7 +908,18 @@ foreground (opposite B<--bg>), and wait for completion 
> > of the command
> >  before exiting.
> >  
> >  
> > -See also: B<--bg> B<man sem>
> > +See also: B<--fg-exit> B<--bg> B<man sem>
> > +
> > +
> > +=item B<--fg-exit>
> > +
> > +Return exit code of command.
> > +
> > +Along with B<--fg> the exit value of GNU B<parallel> will be that of
> > +the command being run.
> > +
> > +
> > +See also: B<--fg-exit> B<--bg> B<man sem>
> >  
> >  
> >  =item B<--fifo>