oksh VS zsh-bench

David Korn's ksh93 was passed on to a new set of developers, who attempted to release a new version; AT&T rolled back these changes due to performance problems which raised questions of support status. It does appear that ksh93 development has resumed, and a new version was released late last year.

https://github.com/ksh93/ksh/releases

The independent pdksh spawned mksh, which is the default shell used in Android (as it has a BSD license); mksh appears to be very much active.

http://www.mirbsd.org/mksh.htm [https site has cert problems]

OpenBSD also forked oksh from pdksh. This is certainly well-maintained.

https://github.com/ibara/oksh

I don't know if this is helpful or just annoying unsolicited "advice"

Anyway, for those of us who like openbsd ksh(all two of us) which is derived from pdksh. there is the project oksh.

https://github.com/ibara/oksh

I like oksh: https://github.com/ibara/oksh

...and that ksh descended from pdksh, and is distributed as the oksh portable project here:

https://github.com/ibara/oksh

The MirBSD Korn Shell also descended from pdksh, and it can be found here:

http://www.mirbsd.org/mksh.htm

I don't know about the feature differences and code quality between these two; they both implement most of ksh88, and a small amount of ksh93.

I prefer mksh when I need something more than a POSIX shell.

Brian Callahan publishes a portable version here: https://github.com/ibara/oksh

Porting from OpenBSD, look for the portable versions and their compat layer. https://github.com/ibara/oksh/blob/master/portable.h

Someone's made a benchmarking system for zsh: https://github.com/romkatv/zsh-bench#premade-configs

Of course, their config is the best according to the benchmark (and ohmyzsh is the slowest option), but DIY configs are also covered, particularly possible performance optimizations.

Unfortunately, running exit is not a great strategy for running benchmarks. For zsh specifically, plugin managers are optimized for fast exit.

romkatv did a great write-up and benchmark within the context of zsh[0]. It's a great read.

[0] https://github.com/romkatv/zsh-bench#how-not-to-benchmark

Given the addition of async rendering in the latest release of spaceship, I wasn't sure whether I should include performance in the list of features found in powerlevel10kbut but not in spaceship. I used zsh-bench to benchmark powerlevel10k on my laptop running on battery (I'm writing this on a train) with a config that makes powerlevel10k looks similar to spaceship. I simply ran p10k configure and chose what looked most similar: Lean Style, UNICODE, 256 colors, two lines, etc. Here are the benchmark results:

Obligatory link since you are engaging in profiling interactive zsh: https://github.com/romkatv/zsh-bench.

1.) It's fast. Like, really fast. 1.) It supports deferred loading via zsh-defer 1.) It supports local plugins as well as ones hosted via a git provider (aka: GitHub, GitLab, BitBucket, etc) 1.) The codebase is simple and easy to understand and contribute to 1.) It supports git branches (with tag/shas on the roadmap) 1.) It supports partial plugin loading such as loading Oh-My-Zsh plugins and Prezto modules without loading the whole framework. 1.) There's an easy migration path from legacy plugin managers like Antigen/Antibody. 1.) Plugins are managed via a simple plugins file that makes it easy to share your config with others. 1.) And lots more

In any case, slow zsh startup is always caused by whatever you put in zsh startup files and it's always possible to reduce zsh startup to imperceptible levels without sacrificing any functionality by editing said startup files. There is a bit of info on interactive zsh performance at https://github.com/romkatv/zsh-bench.

Why is this a good thing? Is this a proxy for performance? If so, you can measure performance directly with zsh-bench. This way you can describe the advantage in terms that have real value to end users. For example, you can say that the first prompt appears N milliseconds faster when using Zpy than if you were using something-else.