Re: ob-shell: proposal to remove "posh"

[Matt <matt@excalamus.com>]

 ---- On Thu, 11 Jan 2024 21:30:59 +0100  Matt  wrote --- 

 > The change on August 26, 2022 should have caused a breaking error for someone using the "Policy-compliant Ordinary SHell."  The prompt for "posh" in "org-babel-shell-set-prompt-commands" is valid PowerShell syntax (AFAIKT) and invalid bash/dash syntax:
 > 
 > function prompt { "org_babel_sh_prompt> " }
 > 
 > It's not clear to me what this would do in the "Policy-compliant Ordinary SHell." 

It would cause an error.

I was able to build the "Policy-compliant Ordinary SHell" on Guix using:

#+begin_src guile
(use-modules (guix packages)
             (guix download)
             (guix build-system gnu)
             (gnu packages autotools)
             (gnu packages perl)
             ((guix licenses) #:prefix license:))

(define-public posh
  (package
    (name "posh")
    (version "0.14.1")
    (source (origin
              (method url-fetch)
              (uri (string-append
                    "https://salsa.debian.org/clint/posh/-/archive/debian/"
                    version "/posh-debian-" version ".tar.gz"))
              (sha256
               (base32
                "070xnn996cjnc5yzp5819y36sgfikkrplhri4kx5r36h1fmp641d"))))
    (native-inputs (list autoconf automake perl))
    (build-system gnu-build-system)
    (home-page "https://salsa.debian.org/clint/posh")
    (synopsis "Policy-compliant Ordinary SHell")
    (description
     "Policy-compliant Ordinary SHell
posh is a stripped-down version of pdksh that aims for compliance with
Debian's policy, and few extra features.")
    (license (list license:gpl2+))))

posh
#+end_src

The result is:

ahab@pequod /gnu/store/64wiqdp9lqjgsz0jg1v1sq2b3afincrb-posh-0.14.1/bin$ ./posh
$ function prompt { "org_babel_sh_prompt> " }
./posh: function: not found

This is expected because "function" is not a keyword in the "Policy-compliant Ordinary SHell."  According to the man page:

#+begin_quote
name () command

  Defines the function name. See Functions below. Note that redirections
  specified after a function definition are performed whenever the
  function is executed, not when the function definition is executed.

-- https://manpages.debian.org/bookworm/posh/posh.1.en.html
#+end_quote

So, yes, indeed, commit a35d1636 introduced a breaking change for the "Policy-compliant Ordinary SHell."

--
Matt Trzcinski
Emacs Org contributor (ob-shell)
Learn more about Org mode at https://orgmode.org
Support Org development at https://liberapay.com/org-mode