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Comment by rusticpenn | Hacker News Reader

As far as I know, fish is not compatible with bash scripts ( most legacy stuff) and this makes zsh attractive.

I don't get it. Are you executing extremely convoluted bash one liners at your shell prompt?

I still write for bash and use a bash shebang to run it when I need to script. Mostly because the likelihood a colleague or whoever else comes along later happens to be using fish is pretty low. Bash remains the most portable option!

I tried fish and uninstalled it because nothing from stackoverflow worked.

Sure, I could spend time learning the fish syntax. But I won’t, since zsh works.

I see. I just dump that kind of stuff in a bash script or bash -c '...' it directly if necessary.

Still, to each his own! That's the great thing about having a glut of viable options.

I often find I write out a series of commands interactively in the shell, then decide I want to save them as a shell script, which I might then want to share.

I enjoyed fish, but found it too annoying to have to translate things into bash when I wanted to share them.

exactly, that's why im back too.

back to zsh from fish, that is.

A lot of CLIs don't ship with fish autocompletion :/

Generally my workflow when developing scripts is running individual commands on the CLI so I can see what it's doing so I can get it right. This is not possible with fish unless I start a bash shell, so at that point, what is the point? With zsh, most of the code I would run in a bash script still runs in a zsh interactive session. Sure there a few edge cases, but they're quite well documented.

Generally my workflow when developing scripts (in Python) is to run individual functions in the repl so I can get it right.

This isn't possible with bash unless I start the python repl, so at that point, what is the point?

Hey, it's possible you spend a lot of time writing scripts, and they need to be bash compatible. Zsh is great for that.

Just wanted to reflect how made-up this sounds to those of us who treat sh like any other language.

> Generally my workflow when developing scripts (in Python) is to run individual functions in the repl so I can get it right.

As a matter of fact, this is exactly what I do when I write Python scripts too. It helps understand exactly what things do quickly and figure certain smaller things.

> Just wanted to reflect how made-up this sounds to those of us who treat sh like any other language.

What do you think sounds made-up?

I mean that "can't use fish because I have to use bash to write bash" makes about as much sense to me, given how I use the terminal, as "can't use fish because I have to use python to write python".

I'm assuming that means you write more shell scripts than I do, or think of the context switch between shells as qualitatively different from the context switch between shell and (some other) repl. All of which is fine.

From the fush documentation:

  Special variables

  Some bash variables and their closest fish equivalent:
    $*, $@, $1 and so on: $argv
    $?: $status
    $$: $fish_pid
    $#: No variable, instead use count $argv
    $!: $last_pid
    $0: status filename
    $-: Mostly status is-interactive and status is-login

Replacing «$$» with «$fish_pid»? A contentious choice at the very least – does it also apply to non-interactive fish scripts? «…use count $argv» instead of «$#» – why? Both, $$ and $#, are non-bashism's and go way, way back into the UNIX prehistoric times – hardly bash-ism's.

Fish does not appear to have basic conditional variable expansions, matching affix removals and pattern substitutions, either; i.e. ${_var:-substitute}, ${parameter<# / ##>word}, ${parameter<% / %%>word} and ${parameter/pattern/string}. Or, at least their nearest equivalent are not prominently featured in the documentation.

How often do you type these things in an interactive shell though? Also things like $status and $argv are reminiscent of csh, which also goes back a long way!

With a varying frequency but I do use them in interactive sessions:

  $ grep -c '\$\?' ~/.history
  137
  $ grep -c '\$\$' ~/.history
  30
  $ grep -c '\$!' ~/.history
  6
  $ grep -c '\$#' ~/.history
  13

Less so when it comes to affix removals… I use them liberally in scripts as well as in data transformation pipelines or more complex one-liners, though.

I also semi-frequently quit the shell with «kill -9 $$» when I do not want to pollute the shell history with garbage, which is not refelcted in the count above for obvious reasons. It is quick and efficient.

> Also things like $status and $argv are reminiscent of csh, which also goes back a long way!

Ah, I thought somebody would mention csh as the prior art! Frankly, the C shell syntax have never really clicked with me precisely because of the more verbose syntax, and, as soon as other shells have borrowed history, job control, aliases and a few other features from (t)csh, I was out of the house!

Ah right; I never do that kind of stuff.

I wonder if you can set "$$=$pid" in some hook in fish (I don't use fish, or even like it for that matter, albeit for different reasons).

Longer names like $status and $pid are actually nicer in scripts IMHO, I typically use those in zsh (which often supports for csh-ish long names and Bourne short names) scripts as it's just a bit clearer. Same with short (-q) vs. long (--quiet) flags: short is great for interactive CLI, long often nicer in scripts. especially with lesser used flags.

Yes, zsh – which has been my daily driver for more than two decades – offers the best of both worlds, long and short names for most of the useful variables, but those do not affect the [expected] core shell functionality.

I suppose, I should have made my point clearer earlier on. A UNIX shell (along with the terminal) is such a fundamental tool that a substantial departure or a paradigm shift from long standing foundational conventions or from the familiar syntax had better bring at least a tenfold increase in productivity for me – to substantiate the said departure. Then I will happily change my workflow and retrain my muscle memory to adapt. scsh is the only other shell that came close to that at some point in space and time, however, it seems to have perished into the oblivion.

A new shell with reasonable and more new user friendly defaults at the expense of missing core shell features does not reach the tipping point for me.

bash isn't compatible with python either, unless you use #!/usr/bin/python or the like.

All my shell scripts start with #!/bin/sh, so the language my user shell runs is irrelevant. Sometimes I do have to preface copypasta with "bash" and end it with "exit", but it ain't the end of the world.

There are a bunch of good reasons to prefer one shell over another, this isn't one of them.

Indeed, just use the shebang #!/bin/sh (if it's posix sh), and #!/bin/bash if you must use bash functionality. There is no reason to not use a different interactive shell.

Please use #!/usr/bin/env bash if you're using bash. It seems more common to have env in /usr/bin than it is to have bash in /bin. On BSD systems, bash is often in /usr/local/bin, and on macOS the user often has a more modern bash in /opt/homebrew/bin or other package manager directory.

> bash isn't compatible with python either, unless you use #!/usr/bin/python or the like.

You're rather aggressively missing the point.

If you need to write and maintain bash scripts but use fish as your command line, you now need to know the idiosyncrasies of both shells ...

If you want to write portable scripts and use a reasonable interactive shell, you need to know two shells anyway. Scripts should ideally be written to only use shell features defined in POSIX, since bash isn't available on every system. It's available pretty widely, but not on e.g. Alpine Linux by default, and the version on macOS is so ancient it doesn't have features like wait -n.

Unless you're going to use rlwrap /bin/dash as your default interactive shell (please don't) you need to know both your interactive shell and standard shell if you're going to write portable scripts.

> Scripts should ideally be written to only use shell features defined in POSIX, since bash isn't available on every system.

I don't write system scripts that need to run on systems without bash and have not needed to do that for a long, long time.

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