Offer a ZSH_EXECUTABLE_PATH or similar?

[okdana]

(workers/42202)

Sebastian had wanted some kind of parameter that provided the real, absolute path to the running zsh executable. I responded:

It's slightly irritating because there's no single cross-platform way to do it.
On Linux you can use /proc/self/exe, and some BSDs have a similar mechanism, but
then there's macOS and Solaris and AIX and so on.

I have wanted this feature in the past myself, though, so i would definitely be
in favour of a ZSH_EXECUTABLE_PATH or something. In fact i may look into it now
that you bring it up.

I did look into it, and i came up with a solution that works reliably on all major platforms except for OpenBSD — see my dana/execpath branch. I didn't post it, though; was worried it was too much effort for a feature that not many people will use. I did find that there was some demand for it, however — see below. Not sure if i want to proceed with it or not. If i do, maybe it belongs in zsh/system or something instead?

• https://unix.stackexchange.com/questions/87061/absolute-path-to-currently-running-zsh
• https://www.zsh.org/mla/users/2013/msg00674.html
• https://www.zsh.org/mla/users/2017/msg00530.html
• https://www.zsh.org/mla/workers/2018/msg00008.html
• https://stackoverflow.com/questions/3572030/bash-script-absolute-path-with-osx
• https://stackoverflow.com/questions/10412162/how-can-i-simply-retrieve-the-absolute-path-of-the-current-script-multi-os-solu