forkrun VS pueue

EDIT: moved code + example to GITHUB

One example that I dont know how to do streaming for involves breaking up the stdin stream and sending it to different places, but where you determine where to send it in realtime. This isnt the code that spawned this particular thread, but a good example of this is in this function I wrote called forkrun.

If you want an example of a really optimized bash script check out my forkrun utility. I spent a really long time optimizing it. It parallelizes loops (like xargs -P and parallel), and for problems with "many very quick iterations" (e.g., sha256sum of a million tiny files) it is twice as fast as the fastest method available via xargs or parallel (which means it is outpacing well optimized compiled C/C++ binaries).

as it so happens, I recently wrote a script called forkrun that parallelizes loops really fast. In particular for things like your simulation that require running 1 at a time in parallel (N parallel batches of 1 simulation, as opposed to N parallel batches of M simulations) the parallelization framework itself is 7x faster than xargs -l 1 -P N and ~25x faster than parallel -j N.

However, if you have bash 4 or later, using bash coprocs can offer much better performance. The idea is that you spawn a bunch of persistent coprocs and pipe data to them, allowing you to parallelize the loop without forking each individual iteration. I wrote / am writing a utility called forkrun that parallelizes loops using bash coprocs. You're welcome to use it, though heads up it is still in beta (almost everything works, but I am still debugging the -k flag sometimes not working properly...-k ensures the output order is the same as input order). If nothing else it gives a real world example of parallelizing using coprocs.

Side note: in case you were wondering the actual code that inspired this post is my forkrun utility. If you felt like checking it out Id love to hear any feedback you might have on it.

For me? My personal best script is (by a wide margin) my forkrun utility. It uses bash coprocs to efficiently parallelize loops. Usage is nearly identical to xargs -P <#>. Options are similar to xargs....a few are missing (namely those related to running things interactively), and a few options are things xargs doesnt do but forkrun can.

I wrote a nifty function for parallelizing loops in bash really fast called forkrun. It will, with the help of tail -F, let you do this (among many other things) by writing the output from each parallel worker to a separate file, which you can then monitor in real time with tail -F in another terminal window.

You can probably do a good subset it in bash, it's just a nicer interface with a lot of configurability and several convenience features.

I'm generally a big fan of showing alternatives: https://github.com/Nukesor/pueue/?tab=readme-ov-file#similar...

Would you be willing to write a proper guide on how to do all of these things in bash? It would be great to have this as guide an alternative inside the Pueue wiki and link to it. It'll help people to make a more informed decision on whether they need this tool or not.

there is a command line manager for long running tasks called Pueue. It is released into Nix, Arch, Alpine, Void, etc, but not for Debian based distros. I know that releasing into Debian is a bit more challenging, but I just wanted to ask if anybody here might be interested in packaging it. Just as a disclaimer, I am not the author of this project, just a regular user.

This one? https://github.com/Nukesor/pueue

How about this: https://github.com/Nukesor/pueue/? I have it bookmarked from a thread here from few years back and never got to test it eventually, but maybe it will serve your purposes?

Multiplexing is great for your multiple outputs, but I would highly recommend using pueue & pueued for job control. Lets you organize your background jobs into groups which can be paused, resumed, etc. Also lets you act on jobs from different terminals w/the pueue interface.

pueue -- a queue for tasks, running in background

For the command that takes a long time to complete, I always use pueue to run. This thing let you run multiple commands in order and can schedule the execution later which is really helpful to my workflow.

That said, you're basically building pueue. https://github.com/Nukesor/pueue/blob/main/ARCHITECTURE.md might give you some pointers. From reading it, there seems to be a mishmash of tokio stuff, and then everything gets serialised onto an MPSC channel (that's serviced by TaskHandler, on a single thread that's also responsible for polling for finished processes etc, every 200ms).

exchange for pueue and you can even queue them up.

This is the only one I know of: https://github.com/Nukesor/pueue