On: Parallel – A command-line CPU load balancer written in Rust

[ploxiln]

a version in C that I think was first released before GNU parallel is in "moreutils" https://joeyh.name/code/moreutils/

A few years ago, debian made GNU parallel provide the "/usr/bin/parallel" executable, instead of moreutils. The maintainer of moreutils had some interesting things to say about that: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=597050#75

[paulddraper → ploxiln]

> It is 5143 lines of code, and the anthethesis of a simple, clean, well-designed unix command.

Only 5k? :D

But, yes, the criticisms are valid. I recommend moreutils.

[dagw → paulddraper]

He lost me at the point when he complained that GNU parallel "includes the ability to transfer files between computers". For me at least that is _the_ feature of GNU parallel that actually makes it really useful. Which I guess is the problem with all these discussions, one persons useless bloat is another persons nr. 1 killer feature.

[oblio → dagw]

But in the spirit of Unix, shouldn't parallel exec some file transfer program?

[dagw → oblio]

The actual Perl code calls out to ssh and rsync (or can be configured to use something else) when it's time to actually connect and transfer files. It just does it in a way that is nice and reasonably transparent to the end user.

It felt like his complaint was that that was 'bloat' since Real Men can achieve almost the same thing by just piping some output through some bash scripts they just hacked together.

[ole_tange → dagw]

And it is exactly the hacking part that GNU Parallel tries to help with: A lot of the helper functions in GNU Parallel could be done by expert users (--nice, --tmux, --pipepart, env_parallel, --compress, --fifo, --cat, --transfer, --return, --cleanup, --(n)onall).

But non-expert users will invariably make mistakes (e.g. get quoting wrong, not getting remote jobs to die if the controlling process is killed, or re-scheduling jobs that were killed by --timeout), and why not just have small wrapper scripts built into GNU Parallel that are well-tested, so the non-expert users can enjoy the same stability as the expert users?

[dagw → ole_tange]

Having written my fair share of those hacky wrapper scripts before I discovered GUN parallel I certainly am very happy that they offer everything I need in a single easy to use command.

[ole_tange → oblio]

It does: Rsync.

[ole_tange → paulddraper]

One of the reasons for the high line number count is the decision not to depend on modules that are not part of the core of Perl 5.8.

Quite a few of the lines are to deal with different flavours of operating systems.

The benefit of this is that by copying the same single file you can have GNU Parallel running on FreeBSD 8, Centos 3.9, and Cygwin.

[ole_tange → ploxiln]

> a version in C that I think was first released before GNU parallel

While this is technically correct, it is misleading: GNU Parallel existed before it became GNU. See details on: https://www.gnu.org/software/parallel/history.html