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
