ast VS oksh

I suspect the intended point of comparison is the monolithic Unix of old, where the entirety of the code of the system is (hopefully, ostensibly, allegedly) developed with a single vision, except for the applications in the narrowest sense of the word (e.g. the particular piece of numerics you need to design your airplane or whatnot, but not the editor you used to write it, the cluster scheduler you used to run it, the typesetter you used to write down your results, or the 3D viewer you used to present them).

One example that’s just plain interesting to read to see what things people were exploring (because, let’s admit it, historical Unix source gets plain boring after a while) is AT&T Research’s https://github.com/att/ast.

Aha, I shall have a dig through https://github.com/att/ast/tree/master/src/lib/libtksh then.

Thank you kindly.

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