this post was submitted on 15 Jan 2025

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Am I crazy in thinking that bash is good enough for production? (lemm.ee)

submitted 2 weeks ago by [email protected] to c/[email protected]

120 comments fedilink hide all child comments

This may make some people pull their hair out, but I’d love to hear some arguments. I’ve had the impression that people really don’t like bash, not from here, but just from people I’ve worked with.

There was a task at work where we wanted something that’ll run on a regular basis, and doesn’t do anything complex aside from reading from the database and sending the output to some web API. Pretty common these days.

I can’t think of a simpler scripting language to use than bash. Here are my reasons:

Reading from the environment is easy, and so is falling back to some value; just do ${VAR:-fallback}; no need to write another if-statement to check for nullity. Wanna check if a variable’s set to something expected? if [[ <test goes here> ]]; then <handle>; fi
Reading from arguments is also straightforward; instead of a import os; os.args[1] in Python, you just do $1.
Sending a file via HTTP as part of an application/x-www-form-urlencoded request is super easy with curl. In most programming languages, you’d have to manually open the file, read them into bytes, before putting it into your request for the http library that you need to import. curl already does all that.
Need to read from a curl response and it’s JSON? Reach for jq.
Instead of having to set up a connection object/instance to your database, give sqlite, psql, duckdb or whichever cli db client a connection string with your query and be on your way.
Shipping is… fairly easy? Especially if docker is common in your infrastructure. Pull Ubuntu or debian or alpine, install your dependencies through the package manager, and you’re good to go. If you stay within Linux and don’t have to deal with differences in bash and core utilities between different OSes (looking at you macOS), and assuming you tried to not to do anything too crazy and bring in necessary dependencies in the form of calling them, it should be fairly portable.

Sure, there can be security vulnerability concerns, but you’d still have to deal with the same problems with your Pythons your Rubies etc.

For most bash gotchas, shellcheck does a great job at warning you about them, and telling how to address those gotchas.

There are probably a bunch of other considerations but I can’t think of them off the top of my head, but I’ve addressed a bunch before.

So what’s the dealeo? What am I missing that may not actually be addressable?

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[–] [email protected] 2 points 2 weeks ago* (last edited 2 weeks ago) (2 children)

Run checkbashisms over your $PATH (grep for #!/bin/sh). That's the problem with Bash.
#!/bin/sh is for POSIX compliant shell scripts only, use #!/bin/bash if you use bash syntax.

Btw, i quite like yash.

[–] [email protected] 2 points 2 weeks ago

Always welcome a new shell. I’ve not heard of yash but I’ll check it out.

[–] [email protected] 1 points 2 weeks ago (1 children)

Any reason to use #!/bin/sh over #!/usr/bin/env sh?

[–] [email protected] 1 points 2 weeks ago* (last edited 2 weeks ago) (1 children)

I personally don't see the point in using the absolute path to a tool to look up the relative path of your shell, because shell is always /bin/sh but the env binary might not even exist.

Maybe use it with bash, some BSD's or whatever might have it in /usr without having /bin symlinked to /usr/bin.

[–] [email protected] 1 points 2 weeks ago (1 children)

There are times when doing so does make sense, eg if you need the script to be portable. Of course, it’s the least of your worries in that scenario. Not all systems have bash being accessible at /bin like you said, and some would much prefer that you use the first bash that appears in their PATH, e.g. in nix.

But yeah, it’s generally pretty safe to assume /bin/sh will give you a shell. But there are, apparently, distributions that symlink that to bash, and I’ve even heard of it being symlinked to dash.

[–] [email protected] 1 points 2 weeks ago* (last edited 2 weeks ago) (1 children)

Not all systems have bash being accessible at /bin like you say

Yeah, but my point is, neither match they /usr/bin/env. Bash, ok; but POSIX shell and Python, just leave it away.

and I’ve even heard of it being symlinked to dash.

I think Debian and Ubuntu do that (or one of them). And me too on Artix, there's dash-as-bin-sh in AUR, a pacman hook that symlinks. Nothing important breaks by doing so.

[–] [email protected] 1 points 2 weeks ago* (last edited 2 weeks ago)

Leaving it away for Python? Are you mad? Why would you want to use my system Python instead of the one specified in my PATH?

[–] [email protected] 1 points 2 weeks ago (1 children)

I'm fine with bash for ci/cd activities, for what you're talking about I'd maybe use bash to control/schedule running of a script in something like python to query and push to an api but I do totally get using the tools you have available.

I use bash a lot for automation but PowerShell is really nice for tasks like this and has been available in linux for a while. Seen it deployed into production for more or less this task, grabbing data from a sql server table and passing to SharePoint. It's more powerful than a shell language probably needs to be, but it's legitimately one of the nicer products MS has done.

End of the day, use the right tool for the job at hand and be aware of risks. You can totally make web requests from sql server using ole automation procedures, set up a trigger to fire on update and send data to an api from a stored proc, if I recall there's a reason they're disabled by default (it's been a very long time) but you can do it.

[–] [email protected] 2 points 2 weeks ago (2 children)

People have really been singing praises of Powershell huh. I should give that a try some time.

But yeah, we wield tools that each come with their own risks and caveats, and none of them are perfect for everything, but some are easier (including writing it and addressing fallovers for it) to use in certain situations than others.

It’s just hard to tell if people’s fear/disdain/disgust/insert-negative-reaction towards bash is rational or more… tribal, and why I decided to ask. It’s hard to shake away the feeling of “this shouldn’t just be me, right?”

[–] [email protected] 2 points 2 weeks ago (2 children)

I have to wonder if some of it is comfort or familiarity, I had a negative reaction to python the first time I ever tried it for example, hated the indent syntax for whatever reason.

[–] [email protected] 2 points 2 weeks ago* (last edited 2 weeks ago)

The indent syntax is one of the obviously bad decisions in the design of python so it makes sense

[–] [email protected] 2 points 2 weeks ago

Creature comfort is a thing. You’re used to it. Familiarity. You know how something behaves when you interact with it. You feel… safe. Fuck that thing that I haven’t ever seen and don’t yet understand. I don’t wanna be there.

People who don’t just soak in that are said to be, maybe, adventurous?

It can also be a “Well, we’ve seen what can work. It ain’t perfect, but it’s pretty good. Now, is there something better we can do?”

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