Thanks for the tip Ole! I will experiment with this flag.
I tried to find the flag with the keyword "last", and didn't find
anything useful, but I'm not a native english speaker, and that
keyword might not be sensible to begin with, "latest" makes a lot of
sense.
On Thu, Feb 20, 2025 at 7:10 PM Ole Tange <o...@tange.dk> wrote:
>
> On Fri, Jan 24, 2025 at 6:26 AM Glen Huang <hey...@gmail.com> wrote:
> >
> > Is it possible to make parallel run multiple commands
> >
> > $ parallel cmd ::: A B C
> >
> > And display the output as
> >
> > $ parallel cmd ::: A B C
> > A: <last line from cmd A>
> > B: <last line from cmd B>
> > C: <last line from cmd C>
> >
> > Where the last line from each command output is always displayed
> > in-place in real time at the same position, overwriting the previous
> > line from the same command, and the name to identify each command is
> > configurable by the user?
>
> What you describe sounds exactly as --latest-line:
>
> --latest-line
> --ll
> Print the latest line. Each job gets a single line that is updated
> with the latest output from the job.
>
> Example:
>
> slow_seq() {
> seq "$@" |
> perl -ne '$|=1; for(split//){ print; select($a,$a,$a,0.03);}'
> }
> export -f slow_seq
> parallel --shuf -j99 --ll --tag --bar --color slow_seq {}
> ::: {1..300}
>
> See also: --line-buffer
>
> It will keep the oldest running job on the screen until it finishes.
> So there may be younger jobs running that will only be visible when
> that job ends.
>
> Run the example a few times. I find it oddly satisfying to watch.
>
> > I skimmed through the document, couldn't really find the answer.
> > Wonder if it's possible at all?
>
> What words should be in the description so you would have found it?
>
> Did you look at
> https://www.gnu.org/software/parallel/parallel_options_map.pdf?
>
> While that PDF looks messy (If you know how to penalize edge crossing
> in Graphviz-Neato let me know - it would make it so much nicer), you
> would look for an option similar to your use (e.g. --line-buffer) and
> then look at what options are related to that.
>
>
> /Ole
