Re: Is there some syntax for executing {} for 1..Inf?

[Ævar Arnfjörð Bjarmason]

On Thu, Dec 7, 2017 at 9:16 PM, Ole Tange <ole@tange.dk> wrote:
> On Thu, Dec 7, 2017 at 1:28 PM, Martin Møller Skarbiniks Pedersen
> <traxplayer@gmail.com> wrote:
>> On 7 December 2017 at 00:37, Ævar Arnfjörð Bjarmason <avarab@gmail.com>
>> wrote:
>>>
>>> I recently had a use-case for:
>>>
>>>     parallel 'cmd {}' ::: {1..Inf}
>>
>> Maybe something like this:
>>
>> yes | cat -n | cut -f1 | parallel ' cmd {} '
>
> Or shorter:
>
>   yes | parallel cmd {#}

Thanks, on a related note isn't the following a bug:

This works as expected, quits soon after the 2nd job fails:

    $ yes | parallel-20171122/src/parallel --jobs=2 --halt-on-error
soon,fail=1 'echo {#}; if test {#} -ge 2; then exit 1; fi'
    1
    2
    parallel: This job failed:
    echo 2; if test 2 -ge 2; then exit 1; fi
    parallel: Starting no more jobs. Waiting for 1 jobs to finish.
    3
    parallel: This job failed:
    echo 3; if test 3 -ge 2; then exit 1; fi

But If I change that to:

    --jobs=1 --halt-on-error soon,fail=1

It'll go on forever, however this'll "work":

    --jobs=1 --halt-on-error now,fail=1

Maybe I'm missing some subtlety here, but this doesn't seem to behave
as documented, and is certainly unexpected: "’soon’ which means wait
for all running jobs to complete, but start no new jobs".

The bug appears to be in this code:

        if($Global::halt_when eq "soon"
           and scalar(keys %Global::running) > 0) {

Which, not knowing the internals well, should be something like:

        if($Global::halt_when eq "soon"
           and $Global::max_jobs_running == 1 or scalar(keys
%Global::running) > 0) {

Or at least that makes this work for me.