I wrote 2x 200 line-ish shell scripts recently, and it was simply terrible, and although I'm increasingly convinced we need a shell like abstraction, I can't believe `bash` is the best we can do. Really hope I find one of these alt shells that suits me. Not a fan of Python but xonsh looks really cool too.

If you want a traditional Unix-like shell that is mostly sensible in the places where Bash is not, check out Zsh. It has a ton of complicated features, but most Bash scripts can be ported easily (if not outright copied and pasted). Zsh has fewer footguns by default than Bash, and it has more "safety" settings that you can enable.

There is also the Oil shell, whose creator often posts on HN, and which I think is meant to be a superset of Bash, but I have not used it myself and can't vouch for it.

As for the alt shells, I've was specifically interested in Elvish, but I dropped it as soon as I saw that they don't support parameter interpolation in string literals, like `"${HOME}/.local"`. This is such a common operation in shell scripts that I have no interest in a shell that doesn't support it, and I can't imagine why Elvish doesn't.

http://www.oilshell.org/release/latest/doc/idioms.html

It removes the need to quote every variable, and this is fantastic

Or is it like Neovim vs. Emacs at that point, where neither one is "better" and it's just a matter of taste and/or whichever one you happened to try first?

Oh.. I just tested here. It works!

  $ mkdir -p /q/a\ b/x
  $ a="a b"
  $ ls /q/$a
  x

  $ a="a b"
  $ ls /q/$a
  ls: cannot access '/q/a': No such file or directory
  ls: cannot access 'b': No such file or directory

Anyway, I want to link also to

http://www.oilshell.org/release/latest/doc/upgrade-breakage....

http://www.oilshell.org/release/latest/doc/warts.html

http://www.oilshell.org/release/latest/doc/known-differences... <- here it talks about zsh a bit

    show_nargs() { print $# }

    q=
    show_nargs $q    # 0
    show_nargs "$q"  # 1

    $ echo 'aaa' > a.txt
    $ echo 'bbb' > b.txt
    $ TMP_DIR="" # Mistake! Missing arg, failed search, typo'd name, etc.
    $ cp a.txt b.txt $TMP_DIR
    $ cat b.txt
    aaa
    $ # The contents of b.txt are lost.

Actually there's a wave of unixy tools being written in Go and Rust and I think there might be a suitable cp replacement already, but it's up to distros to package it.

PERL. Sh, awk, sed and mini-C all at once.

Traditional shell scripting languages are great at exactly three things: typing commands interactively, running other programs, and sourcing other shell scripts. They are also is distinct in that they are "stringly-typed" (i.e. everything is a string), and moreover that syntactically bare symbols are also strings.

Typing commands interactively is essential because... it's a shell. That's what it's for. Most programming languages do not and should not optimize for this. But it's literally the purpose of a shell, so a shell should be good at it.

"Running other programs" includes invoking them (literally 0 extra syntax), piping them (one letter: |), and redirecting the standard input and output streams to files (>, <, <<, etc.). This is one of the great innovations of Unix and nothing holds a candle to its elegance and convenience, even if sometimes we get frustrated that pipes are "dumb" streams of bytes and not something more structured.

"Sourcing other shell scripts" practically isn't much different from "running another shell process", except that source'd shell scripts can set shell parameters and environment variables, which is an important part of e.g. the X11 startup system: the global /etc/X11/Xsession script sources the user's ~/.xsession script, so any environment variables set in the latter are propagated to the former, and thereby are inherited by the X11 window manager when it eventually starts. If you wrote the /etc/X11/Xsession script in any other programming language, you'd have to inspect the environment variables of the ~/.xsession process and "merge" those values back into the current process' environment.

On being stringly-typed, I think it's mostly good in the context of the "two things that it's good at" described above. It cuts down on syntactical noise (otherwise "everything" "would" "always" "be" "quoted" "everywhere"), makes string interpolation painless, and generally supports the "typing commands interactively" use case. Make and Tcl are the only other popular languages in this category. Perl and Ruby allow it in specially-delineated areas of code. Moreover, Bash, Ksh, and Zsh all have arrays, which helps fix some of the biggest problems of everything being a string.

In short, if your program can make good use of the above features, then a traditional shell is a great choice. If you program does not need those features, do not write your program using a shell script, because shell languages are awkward at best in pretty much all areas.

And if you are considering an "alt" or "neo" shell language, in my opinion it must excel in the above two categories. Being stringly-typed is a matter of taste, but the language should also probably support bare-symbols-as-strings and string interpolation.

Python, for example, is not a good shell scripting language because it is not easy to type nontrivial commands interactively, it lacks tidy syntax for input/output redirection (even though it's actually pretty easy using the standard library), and it lacks bare-symbols-as-strings. So instead of:

    #!/bin/sh
    foo -x 1 -y 2 "$ABC" | bar --json -

    #!/usr/bin/env python3
    import os
    from subprocess import Popen, PIPE, run

    foo_cmd = ['foo', '-x', '1', '-y', '2', os.environ['ABC']]
    bar_cmd = ['bar', '--json', '-']
    with Popen(foo_cmd, stdout=PIPE) as foo_proc:
        foo_proc.stdin.close()
        run(bar_cmd, stdin=foo_proc.stdout)

Please add another standard output stream.

stdout is for output

stderr is for error messages

stdlog for status/tracking, verbose output, event streams. Too often this gets shunted to stderr, and I don't want to logfile hunt. Other examples: download status from curl, verbose output flags in things like ssh and other comm programs that need configuration debugging on the regular, and others.

Nushell seems to also focus on json output for commands. I think this should be a requirement pushed into all unix commands that do output (LS! please please please a json output flag for simple ls which CANNOT BE PARSED RELIABLY).

  `template${Math.random() > 0.5 ? 'strings' : 'literals'} have beern part of the language since 2015!`

    $E:HOME'/.local'

I fear there will be no defacto bash replacement for many years.

Bash. (except MacOS I guess)

why? because it is the best thing that everyone can agree on as being the stock shell that should always be installed by default.

until we collectively agree on a replacement, bash will remain, along with all of its problems and everyone will write for it because it's the standard shell that's always installed.

many much better shells exist. we can't agree on what should supplant bash, and so it remains. everywhere.

Otherwise for older versions you can just do `my.exe; if ($lastexitcode) { "failure code here" }`. It's not nice but certainly not impossible to do.

You mean the fact that it gets put into the $LASTEXITCODE variable instead of putting the command directly into the conditional?

Its even better then that as you can fail individual commands with their -ErrorAction argument.

BOM is not there any more.

I think Powershell more advanced ecosystem with a default output more like the sqlite tables of nushell would be wonderful: the objects handled by PS would be more naturally suitable to this, and would compose more easily.

Okay, I'll bite - how does it handle filenames with spaces and newlines in them? I have a strong case of Stockholm syndrome with bash because I figured out how to deal with the first one, but I'd love a system that deals with that sanely.

I am in the process of switching most of my shell scripts over to Python; I wonder whether nushell would be the better option.

Yeah, this is a very fair criticism. We're working on it :)