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 withcurl
. 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 forjq
. - 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
ordebian
oralpine
, 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?
Can I slap a decorator on a Bash function? I love my
(via
tenacity
, even if it’s a bit wordy).A few responses for you:
- I deeply despise
bash
. That Linux shell defaults settled on it is an embarrassment to the entire open source community. - Yes, Bash is good enough for production. It is the world’s current default shell. As long as we avoid it’s fancier features (which all suck for production use), a quick bash script is often the most reasonable choice.
- For the love of all that is holy, put your own personal phone number and no one else’s in the script, if you choose to use
bash
to access a datatbase. There’s thousands of routine ways that database access can hiccup, and bash is suitable to help you diagnose approximately 0% of them. - If I found out a colleague had used bash for database access in a context that I would be expected to co-maintain, I would start by plotting their demise, and then talk myself down to having a severe conversation with them - after I changed it immediately to something else, in production, ignoring all change protocols.
Why internet man hate Bash? Bash do many thing. Make computer work.
I actually (also) love
bash
, and use it like crazy.What I really hate is that
bash
is so locked in legacy that it’s bad features (on a scripting language scale, which isn’t fair) (and of which there are too many to enumerate) are now locked in permanently.I also hate how convention has kept other shells from replacing bash’s worst features with better modern alternatives.
To some extent, I’m railing against how hard it is to write a good Lexer and a Parser, honestly. Now that bash is stable, there’s little interest in improving it. Particularly since one can just invoke a better scripting language for complex work.
I mourn the sweet spot that Perl occupies, that Bash and Python sit on either side of, looking longingly across the gap that separated their practical use cases.
I have lost hope that Python will achieve shell script levels of pragmatism. Although the
invoke
library is a frigging cool attempt.But I hold on to my sorrow and anger that Bash hasn’t bridged the gap, and never will, because whatever it can invoke, it’s methods of responding to that invocation are trapped in messes like “if…fi”.
What do you suppose bash could do here? When a program reaches some critical mass in terms of adoption, all your bugs and features are features of your program, and, love it or hate it, somebody’s day is going to be ruined if you do your bug fixes, unless, of course, it’s a fix for something that clearly doesn’t work in the very sense of the word.
I’m sure there’s space for a clear alternative to arise though, as far as scripting languages go. Whether we’ll see that anytime soon is hard to tell, cause yeah, a good lexer and parser in the scripting landscape is hard work.
What do you suppose bash could do here?
- For the love of all that is holy, it’s not 1970, we don’t need to continue to tolerate “if … fi”
- Really everything about how bash handles logic bridging multiple lines of a file. (loops, error handling, etc)
I’m sure there’s space for a clear alternative to arise though, as far as scripting languages go.
The first great alternative/attempt does exist, in
PowerShell
. (Honorable mention to Zsh, but I find it has most of the same issues as bash without gaining the killer features of pwsh.)But I’m a cranky old person so I despise (and deeply appreciate!) PowerShell for a completely different set of reasons.
At the moment I use whichever gets the job done, but I would love to stop switching quite so often.
I hold more hope that PowerShell will grow to bridge the gap than that a fork of bash will. The big thing PowerShell lacks is bash’s extra decades of debugging and refinement.
Could you explain those db connection hiccups you’ve seen?
Sure.
I’ll pick on
postgres
because it’s popular. But I have found that most databases have a similar number of error codes.https://www.postgresql.org/docs/current/errcodes-appendix.html
It’s not an specific error that’s the issue, it’s the sheer variety of ways things can go wrong, combined with bash not having been architected with the database access use case in mind.
I find this argument somewhat weak. You are not going to run into the vast majority of those errors (in fact, some of them are not even errors, and you will probably never run into some of those errors as Postgres will not return them, eg some error codes from the sql standard). Many of them will only trigger if you do specific things: you started a transaction, you’ll have to handle the possible errors that comes with having a transaction.
There are lots of reasons to never use bash to connect to a db to do things. Here are a couple I think of that I think are fairly basic that some may think they can just do in bash.
- Write to more than 1 table.
- Write to a table that has triggers, knowing that you may get a trigger failure.
- Use transactions.
- Calling a stored procedure that will raise exceptions.
- Accepting user input to write that into a table.
One case that I think is fine to use bash and connect to a db is when all you need to do a
SELECT
. You can test your statement in your db manager of choice, and bring that into bash. If you need input sanitization to filter results, stop, and use a language with a proper library. Otherwise, all the failure cases I can think of are: a) connection fails for whatever reason, in which case you don’t get your data, you get an exit code of 1, log to stderr, move on, b) your query failed cause of bad sql, in which case, well, go back to your dev loop, no?This is why I asked what sort of problems have you ran into before, assuming you haven’t been doing risky things with the connection. I’m sorry, but I must say that I’m fairly disappointed by your reply.
I find this argument somewhat weak.
Lol. Me too. I was just trying to give the shorthand version.
Your explanation is much better.
Edit: but it doesn’t sound like you really needed a detailed answer from me, anyway.
I actually love listening to or reading someone else’s war story, and tbh the entire purpose of this post is to dig those up. Bash is one of those places where a lot about it is passed around as tribal knowledge. So I’d really love to hear how things have failed.
Fair enough.
Here’s what I remember: invoking
SQL
containing inserts frombash
has resulted in lost data, when fairly unsurprising database things happened, sincebash
didn’t really expect to be in charge of logging the details of the attempted change. For the error, it wasn’t something surprising - maybe it was “max connections reached”, stuff that will just happen sometimes.The data loss was probably solveable in
bash
, but the scripter didn’t think to (and probably would have needed more effort in a full development tool).
- I deeply despise
Bash is perfectly good for what you’re describing.
Serious question (as a bash complainer):
Have I missed an amazing bash library for secure database access that justifies a “perfectly good” here?
Every database I know comes with an SQL shell that takes commands from stdin and writes query results to stdout. Remember that “bash” never means bash alone, but all the command line tools from cut via jq to awk and beyond … so, that SQL shell would be what you call “bash library”.
Thank you. I wasn’t thinking about that. That’s a great point.
As long as any complex recovery logic fits inside the SQL, itself, I don’t have any issue invoking it from
bash
.It’s when there’s complicated follow-up that needs to happen in bash that I get anxious about it, due to past painful experiences.
Right, that’s when you should look for a driver language that’s better suited for the job, e. g. Python.
What gave you the impression that this was just for development? Bash is widely used in production environments for scripting all over enterprises. The people you work with just don’t have much experience at lots of shops I would think.
It’s just not wise to write an entire system in bash. Just simple little tasks to do quick things. Yes, in production. The devops world runs on bash scripts.
I’ve never had that impression, and I know that even large enterprises have Bash scripts essentially supporting a lot of the work of a lot of their employees. But there are also many very loud voices that seems to like screaming that you shouldn’t use Bash almost at all.
You can take a look at the other comments to see how some are entirely turned off by even the idea of using bash, and there aren’t just a few of them.
This Lemmy thread isn’t representative of the real world. I’ve been a dev for 40 years. You use what works. Bash is a fantastic scripting tool.
I understand that. I have coworkers with about 15-20 years in the industry, and they frown whenever I put a bash script out for, say, a purpose that I put in my example: self-contained, clearly defined boundaries, simple, and not mission critical despite handling production data, typically done in less than 100 lines of bash with generous spacing and comments. So I got curious, since I don’t feel like I’ve ever gotten a satisfactory answer.
Thank you for sharing your opinion!
My #1 rule for the teams I lead is “consistency”. So it may fall back to that. The standard where you work is to use a certain way of doing things so everyone becomes skilled at the same thing.
I have the same rule, but I always let a little bash slide here and there.
Bash is widely used in production environments for scripting all over enterprises.
But it shouldn’t be.
The people you work with just don’t have much experience at lots of shops I would think.
More likely they do have experience of it and have learnt that it’s a bad idea.
I don’t disagree with this, and honestly I would probably support just using bash like you said if I was in a team where this was suggested.
I think no matter how simple a task is there are always a few things people will eventually want to do with it:
- Reproduce it locally
- Run unit tests, integration tests, smoke tests, whatever tests
- Expand it to do more complex things or make it more dynamic
- Monitor it in tools like Datadog
If you have a whole project already written in Python, Go, Rust, Java, etc, then just writing more code in this project might be simpler, because all the tooling and methodology is already integrated. A script might not be so present for many developers who focus more on the code base, and as such out of sight out of mind sets in, and no one even knows about the script.
There is also the consideration that many people simply dislike bash since it’s an odd language and many feel it’s difficult to do simple things with it.
due to these reasons, although I would agree with making the script, I would also be inclined to have the script temporarily while another solution is being implemented.
It’s ok for very small scripts that are easy to reason through. I’ve used it extensively in CI/CD, just because we were using Jenkins for that and it was the path of least resistance. I do not like the language though.
We are not taking about use of Bash in dev vs use Bash in production. This imho incorrect question that skirts around real problem in software development. We talk about use of Bash for simple enough tasks where code rarely changed ( if not written once and thrown away ) and where every primitive language or DSL is ok, where when it comes to building of medium or complex size software systems where decomposition, data structures support, unit tests, etc is a big of a deal - Bash really sucks because it does not allow one to deal with scaling challenges, by scaling I mean where you need rapidly change huge code base according changes of requirements and still maintain good quality of entire code
But not everything needs to scale, at least, if you don’t buy into the doctrine that everything has to be designed and written to live forever. If robust, scalable solutions is the nature of your work and there’s nothing else that can exist, then yeah, Bash likely have no place in that world. If you need any kind of handling more complicated than just getting an error and doing something else, then Bash is not it.
Just because Bash isn’t designed for something you want to do, doesn’t mean it sucks. It’s just not the right tool. Just because you don’t practice law, doesn’t mean you suck; you just don’t do law. You can say that you suck at law though.
Yep. Like said - “We talk about use of Bash for simple enough tasks … where every primitive language or DSL is ok”, so Bash does not suck in general and I myself use it a lot in proper domains, but I just do not use it for tasks / domains with complexity ( in all senses, including, but not limited to team work ) growing over time …
If your company ever has >2 people, it will become a problem.
You’re speaking prophetically there and I simply do not agree with that prophecy.
If you and your team think you need to extend that bash script to do more, stop and consider writing it in some other languages. You’ve move the goalpost, so don’t expect that you can just build on your previous strategy and that it’ll work.
If your “problem” stems from “well your colleagues will not likely be able to read or write bash well enough”, well then just don’t write it in bash.
I’ve only ever used bash.
Well then you guys will love what this guy (by tha name “icitry”) did with bash https://www.youtube.com/watch?v=b_WGoPaNPMY
He created a youtube clone with Bash
That is definitely not something I would do… for work (totally not implying that I miiiight do it for shits and giggles :P).
I didn’t create this post trying to be like “y’all should just use Bash”, nor is it an attempt to say that I like Bash, but I guess that’s how people boil others down to these days. Fanatics only. Normalcy is dead. (I’m exaggerating ofc)
Basically, If you are crazy enough, you csn make anything with any language<br> Hence, me sharing the video
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.
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?”
The nice thing about Powershell is that it was built basically now after learning all the things that previous shells left out. I’m not fluent in it, but as a Bash aficionado, I marveled at how nice it was at a previous job where we used it.
That said, I love Bash and use it for lots of fun automation. I think you’re right to appreciate it as you do. I have no opinion on the rest.
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.
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?”
The indent syntax is one of the obviously bad decisions in the design of python so it makes sense
I just don’t think bash is good for maintaining the code, debugging, growing the code over time, adding automated tests, or exception handling
If you need anything that complex and that it’s critical for, say, customers, or people doing things directly for customers, you probably shouldn’t use bash. Anything that needs to grow? Definitely not bash. I’m not saying bash is what you should use if you want it to grow into, say, a web server, but that it’s good enough for small tasks that you don’t expect to grow in complexity.
small tasks that you don’t expect to grow in complexity
On one conference I heard saying: " There is no such thing as temporary solution and there is no such thing as proof of concept". It’s overexaguration of course but it has some truth to it - there’s a high chance that your “small change” or PoC will be used for the next 20 years so write it as robust and resilient as possible and document it. In other words everything will be extendended, everything will be maintained, everything will change hands.
So to your point - is bash production ready? Well, depends. Do you have it in git? Is it part of some automation pipeline? Is it properly documented? Do you by chance have some tests for it? Then yes, it’s production ready.
If you just “write this quick script and run it in cron” then no. Because in 10 years people will pull their hair screaming “what the hell is hapenning?!”
I find it disingenuous to blame it on the choice of bash being bad when goalposts are moved. Solutions can be temporary as long as goalposts aren’t being moved. Once the goalpost is moved, you have to re-evaluate whether your solution is still sufficient to meet new needs. If literally everything under the sun and out of it needs to be written in a robust manner to accommodate moving goalposts, by that definition, nothing will ever be sufficient, unless, well, we’ve come to a point where a human request by words can immediately be compiled into machine instructions to do exactly what they’ve asked for, without loss of intention.
That said, as engineers, I believe it’s our responsibility to identify and highlight severe failure cases given a solution and its management, and it is up to the stakeholders to accept those risks. If you need something running at 2am in the morning, and a failure of that process would require human intervention, then maybe you should consider not running it at 2am, or pick a language with more guardrails.
it’s (bash) good enough for small tasks that you don’t expect to grow in complexity.
I don’t think you’ll get a lot of disagreement on that, here. As mention elsewhere, my team prefers bash for simple use cases (and as their bash-hating boss, I support and agree with how and when they use bash.)
But a bunch of us draw the line at database access.
Any database is going to throw a lot of weird shit at the bash script.
So, to me, a bash script has grown to unacceptable complexity on the first day that it accesses a database.
We have dozens of bash scripts running table cleanups and maintenece tasks on the db. In the last 20 years these scripts where more stable than the database itself (oracle -> mysql -> postgres).
But in all fairness they just call the cliclient with the appropiate sql and check for the response code, generating a trap.
That’s a great point.
I post long enough responses already, so I didn’t want to get into resilience planning, but your example is a great highlight that there’s rarely hard and fast rules about what will work.
There certainly are use cases for bash calling database code that make sense.
I don’t actually worry much when it’s something where the first response to any issue is to run it again in 15 minutes.
It’s cases where we might need to do forensic analysis that bash plus SQL has caused me headaches.
Yeah, if it feels like a transaction would be helpful, at least go for pl/sql and save yourself some pain. Bash is for system maintenance, not for business logic.
Heck, I wrote a whole monitoring system for a telephony switch with nothing more than bash and awk and it worked better than the shit from the manufacturer, including writing to the isdn cards for mobile messaging. But I wouldn’t do that again if I have an alternative.
Bash is for system maintenance, not for business logic.
That is such a good guiding principle. I’m gonna borrow that.
Pretty much all languages are middleware, and most of the original code was shell/bash. All new employees in platform/devops want to immediately push their preferred language, they want java and rust environments. It’s a pretty safe bet if they insist on using a specific language; then they don’t know how awk or sed. Bash has all the tools you need, but good developers understand you write libraries for functionality that’s missing. Modern languages like Python have been widely adopted and has a friendlier onboarding and will save you time though.
Pretty much all languages are middleware, and most of the original code was shell/bash.
What? I genuinely do not know what you mean by this.
2 parts:
- All languages are middleware. Unless you write in assembly, whatever you write isn’t directly being executed, they are being run through a compiler and being translated from your “middle language” or into 0s and 1s the computer can understand. Middleware is code used in between libraries to duplicate their functionality.
https://azure.microsoft.com/en-us/resources/cloud-computing-dictionary/what-is-middleware/ - Most original code was written in shell. Most scripting is done in the cli or shell language and stored as a
script.sh
file, containing instructions to execute tasks. Before python was invented you used the basic shell because nothing else existed yet
The first part is confusing what “middleware” means. Rather than “duplicating” functionality, it connects libraries (I’m guessing this is what you meant). But that has nothing to do with a language being compiled versus “directly executed”, because compilation doesn’t connect different services or libraries; it just transforms a higher-level description of execution into an executable binary. You could argue that an interpreter or managed runtime is a form of “middleware” between interpreted code and the operating system, but middleware typically doesn’t describe anything so critical to a piece of software that the software can’t run without it, so even that isn’t really a correct use of the term.
The second part is just…completely wrong. Lisp, Fortran, and other high-level languages predate terminal shells; C obviously predates the shell because most shells are written in C. “Most original code” is in an actual systems language like C.
(As a side note, Python wasn’t the first scripting language, and it didn’t become popular very quickly. Perl and Tcl preceded it; Lua, php, and R were invented later but grew in popularity much earlier.)
You are stuck on 100% accuracy and trying to actually stuff to death. The user asked if it’s possible to write an application in bash and the answer is an overwhelming duh. Most assembly languages are emulators and they all predate C.
In addition to not actually being correct, I don’t think the information you’ve provided is particularly helpful in answering OP’s question.
- All languages are middleware. Unless you write in assembly, whatever you write isn’t directly being executed, they are being run through a compiler and being translated from your “middle language” or into 0s and 1s the computer can understand. Middleware is code used in between libraries to duplicate their functionality.
“Use the best tool for the job, that the person doing the job is best at.” That’s my approach.
I will use bash or python dart or whatever the project uses.
I’m afraid your colleagues are completely right and you are wrong, but it sounds like you genuinely are curious so I’ll try to answer.
I think the fundamental thing you’re forgetting is robustness. Yes Bash is convenient for making something that works once, in the same way that duct tape is convenient for fixes that work for a bit. But for production use you want something reliable and robust that is going to work all the time.
I suspect you just haven’t used Bash enough to hit some of the many many footguns. Or maybe when you did hit them you thought “oops I made a mistake”, rather than “this is dumb; I wouldn’t have had this issue in a proper programming language”.
The main footguns are:
- Quoting. Trust me you’ve got this wrong even with
shellcheck
. I have too. That’s not a criticism. It’s basically impossible to get quoting completely right in any vaguely complex Bash script. - Error handling. Sure you can
set -e
, but then that breaks pipelines and conditionals, and you end up with really monstrous pipelines full ofpipefail
noise. It’s also extremely easy to forgetset -e
. - General robustness. Bash silently does the wrong thing a lot.
instead of a
import os; os.args[1]
in Python, you just do$1
No. If it’s missing
$1
will silently become an empty string.os.args[1]
will throw an error. Much more robust.Sure, there can be security vulnerability concerns, but you’d still have to deal with the same problems with your Pythons your Rubies etc.
Absolutely not. Python is strongly typed, and even statically typed if you want. Light years ahead of Bash’s mess. Quoting is pretty easy to get right in Python.
I actually started keeping a list of bugs at work that were caused directly by people using Bash. I’ll dig it out tomorrow and give you some real world examples.
I don’t disagree with your point, but how does
set -e
break conditionals? I use it all the time without issuesPipefail I don’t use as much so perhaps that’s the issue?
It means that all commands that return a non-zero exit code will fail the script. The problem is that exit codes are a bit overloaded and sometimes non-zero values don’t indicate failure, they indicate some kind of status. For example in
git diff --exit-code
orgrep
.I think I was actually thinking of
pipefail
though. If you don’t set it then errors in pipelines are ignored, which is obviously bad. If you do then you can’t usegrep
in pipelines.
Agreed.
Also gtfobins is a great resource in addition to shellcheck to try to make secure scripts.
For instance I felt upon a script like this recently:
#!/bin/bash # ... some stuff ... tar -caf archive.tar.bz2 "$@"
Quotes are OK, shellcheck is happy, but, according to gtfobins, you can abuse tar, so running the script like this:
./test.sh /dev/null --checkpoint=1 --checkpoint-action=exec=/bin/sh
ends up spawning an interactive shell…So you can add up binaries insanity on top of bash’s mess.
Quotes are OK, shellcheck is happy, but, according to gtfobins, you can abuse tar, so running the script like this: ./test.sh /dev/null --checkpoint=1 --checkpoint-action=exec=/bin/sh ends up spawning an interactive shell…
This runs into a part of the unix philosophy about doing one thing and doing it well: Extending programs to have more (absolutely useful) functionality winds up becoming a security risk. The shell is generally geared towards being a collection of shortcuts rather than a normal, predictable but tedious API.
For a script like that you’d generally want to validate that the input is actually what you expect if it needs to handle hostile users, though. It’ll likely help the sleepy users too.
I imagine adding
--
so it becomestar -caf archive.tar.bz2 -- "$@"
would fix that specific caseBut yeah, putting bash in a position where it has more rights than the user providing the input is a really bad idea
gtfobins
Meh, most in that list are just “if it has the SUID bit set, it can be used to break out of your security context”.
I honestly don’t care about being right or wrong. Our trade focuses on what works and what doesn’t and what can make things work reliably as we maintain them, if we even need to maintain them. I’m not proposing for bash to replace our web servers. And I certainly am not proposing that we can abandon robustness. What I am suggesting that we think about here, is that when you do not really need that robustness, for something that may perhaps live in your production system outside of user paths, perhaps something that you, your team, and the stakeholders of the particular project understand that the solution is temporary in nature, why would Bash not be sufficient?
I suspect you just haven’t used Bash enough to hit some of the many many footguns.
Wrong assumption. I’ve been writing Bash for 5-6 years now.
Maybe it’s the way I’ve been structuring my code, or the problems I’ve been solving with it, in the last few years after using
shellcheck
andbash-language-server
that I’ve not ran into issues where I get fucked over by quotes.But I can assure you that I know when to dip and just use a “proper programming language” while thinking that Bash wouldn’t cut it. You seem to have an image of me just being a “bash glorifier”, and I’m not sure if it’ll convince you (and I would encourage you to read my other replies if you aren’t), but I certainly don’t think bash should be used for everything.
No. If it’s missing
$1
will silently become an empty string.os.args[1]
will throw an error. Much more robust.You’ll probably hate this, but you can use
set -u
to catch unassigned variables. You should also use fallbacks wherever sensible.Absolutely not. Python is strongly typed, and even statically typed if you want. Light years ahead of Bash’s mess. Quoting is pretty easy to get right in Python.
Not a good argument imo. It eliminates a good class of problems sure. But you can’t eliminate their dependence on shared libraries that many commands also use, and that’s what my point was about.
And I’m sure you can find a whole dictionary’s worth of cases where people shoot themselves in the foot with bash. I don’t deny that’s the case. Bash is not a good language where the programmer is guarded from shooting themselves in the foot as much as possible. The guardrails are loose, and it’s the script writer’s job to guard themselves against it. Is that good for an enterprise scenario, where you may either blow something up, drop a database table, lead to the lost of lives or jobs, etc? Absolutely not. Just want to copy some files around and maybe send it to an internal chat for regular reporting? I don’t see why not.
Bash is not your hammer to hit every possible nail out there. That’s not what I’m proposing at all.
And I certainly am not proposing that we can abandon robustness.
If you’re proposing Bash, then yes you are.
You’ll probably hate this, but you can use set -u to catch unassigned variables.
I actually didn’t know that, thanks for the hint! I am forced to use Bash occasionally due to misguided coworkers so this will help at least.
But you can’t eliminate their dependence on shared libraries that many commands also use, and that’s what my point was about.
Not sure what you mean here?
Just want to copy some files around and maybe send it to an internal chat for regular reporting? I don’t see why not.
Well if it’s just for a temporary hack and it doesn’t matter if it breaks then it’s probably fine. Not really what is implied by “production” though.
Also even in that situation I wouldn’t use it for two reasons:
- “Temporary small script” tends to smoothly morph into “10k line monstrosity that the entire system depends on” with no chance for rewrites. It’s best to start in a language that can cope with it.
- It isn’t really any nicer to use Bash over something like Deno. Like… I don’t know why you ever would, given the choice. When you take bug fixing into account Bash is going to be slower and more painful.
I’m going to downvote your comment based on that first quote reply, because I think that’s an extreme take that’s unwarranted. You’ve essentially dissed people who use it for CI/CD and suggested that their pipeline is not robust because of their choice of using Bash at all.
And judging by your second comment, I can see that you have very strong opinions against bash for reasons that I don’t find convincing, other than what seems to me like irrational hatred from being rather uninformed. It’s fine being uninformed, but I suggest you tame your opinions and expectations with that.
About shared libraries, many popular languages, Python being a pretty good example, do rely on these to get performance that would be really hard to get from their own interpreters / compilers, or if re-implementing it in the language would be pretty pointless given the existence of a shared library, which would be much better scrutinized, is audited, and is battle-tested. libcrypto is one example. Pandas depends on NumPy, which depends on, I believe, libblas and liblapack, both written in C, and I think one if not both of these offer a cli to get answers as well. libssh is depended upon by many programming languages with an ssh library (though there are also people who choose to implement their own libssh in their language of choice). Any vulnerabilities found in these shared libraries would affect all libraries that depend on them, regardless of the programming language you use.
If production only implies systems in a user’s path and not anything else about production data, then sure, my example is not production. That said though, I wouldn’t use bash for anything that’s in a user’s path. Those need to stay around, possible change frequently, and not go down. Bash is not your language for that and that’s fine. You’re attacking a strawman that you’ve constructed here though.
If your temporary small script morphs into a monster and you’re still using bash, bash isn’t at fault. You and your team are. You’ve all failed to anticipate that change and misunderstood the “temporary” nature of your script, and allowed your “temporary thing” to become permanent. That’s a management issue, not a language choice. You’ve moved that goalpost and failed to change your strategy to hit that goal.
You could use Deno, but then my point stands. You have to write a function to handle the case where an env var isn’t provided, that’s boilerplate. You have to get a library for, say, accessing contents in Azure or AWS, set that up, figure out how that api works, etc, while you could already do that with the awscli and probably already did it to check if you could get what you want. What’s the syntax for
mkdir
? What’s it formkdir -p
? What about other options? If you already use the terminal frequently, some of these are your basic bread and butter and you know them probably by heart. Unless you start doing that with Deno, you won’t reach the level of familiarity you can get with the shell (whichever shell you use ofc).And many argue against bash with regards to error handling. You don’t always need something that proper language has. You don’t always need to handle every possible error state differently, assuming you have multiple. Did it fail? Can you tolerate that failure? Yup? Good. No? Can you do something else to get what you want or make it tolerable? Yes? Good. No? Maybe you don’t want to use bash then.
You’ve essentially dissed people who use it for CI/CD and suggested that their pipeline is not robust because of their choice of using Bash at all.
Yes, because that is precisely the case. It’s not a personal attack, it’s just a fact that Bash is not robust.
You’re trying to argue that your cardboard bridge is perfectly robust and then getting offended that I don’t think you should let people drive over it.
About shared libraries, many popular languages, Python being a pretty good example, do rely on these to get performance that would be really hard to get from their own interpreters / compilers, or if re-implementing it in the language would be pretty pointless given the existence of a shared library, which would be much better scrutinized, is audited, and is battle-tested. libcrypto is one example. Pandas depends on NumPy, which depends on, I believe, libblas and liblapack, both written in C, and I think one if not both of these offer a cli to get answers as well. libssh is depended upon by many programming languages with an ssh library (though there are also people who choose to implement their own libssh in their language of choice). Any vulnerabilities found in these shared libraries would affect all libraries that depend on them, regardless of the programming language you use.
You mean “third party libraries” not “shared libraries”. But anyway, so what? I don’t see what that has to do with this conversation. Do your Bash scripts not use third party code? You can’t do a lot with pure Bash.
If your temporary small script morphs into a monster and you’re still using bash, bash isn’t at fault. You and your team are.
Well that’s why I don’t use Bash. I’m not blaming it for existing, I’m just saying it’s shit so I don’t use it.
You could use Deno, but then my point stands. You have to write a function to handle the case where an env var isn’t provided, that’s boilerplate.
Handling errors correctly is slightly more code (“boilerplate”) than letting everything break when something unexpected happens. I hope you aren’t trying to use that as a reason not to handle errors properly. In any case the extra boilerplate is…
Deno.env.get("FOO")
. Wow.What’s the syntax for mkdir? What’s it for mkdir -p? What about other options?
await Deno.mkdir("foo"); await Deno.mkdir("foo", { recursive: true });
What’s the syntax for a dictionary in Bash? What about a list of lists of strings?
- Quoting. Trust me you’ve got this wrong even with
Over the last ten - fifteen years, I’ve written lots of scripts for production in bash. They’ve all served their purposes (after thorough testing) and not failed. Pretty sure one of my oldest (and biggest) is called
temporary_fixes.sh
and is still in use today. Another one (admittedly not in production) was partially responsible for getting me my current job, I guess because the interviewers wanted to see what kind of person would solve a coding challenge in bash.However, I would generally agree that - while bash is good for many things and perhaps even “good enough” - any moderately complex problem is probably better solved using a different language.