Why aren't python and bash be available in all your systems? Which languages would be?

I would've recommended python, otherwise perl or Haskell (maybe Haskell's too big) or something, but now I'm worried that whatever reason makes python undoable also makes perl etc. undoable

luajit is small, fast(well, it can jit), and has a small but complete standard library and can do FFI pretty easily, should be ideal for most homelab usecase

ldd $(which luajit)                                                                                
        linux-vdso.so.1 (0x00007ffee9dc7000)
        libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fb4db618000)
        libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fb4db613000)
        libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fb4db5f3000)
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fb4db3ca000)
        /lib64/ld-linux-x86-64.so.2 (0x00007fb4db799000)

Python is what you want. You can install it on just about any system.

Other than that maybe Lua but that will be hell.

What about Lua/Luajit?

In most scripting languages you have the interpreter binary and the (standard) libraries as separate files. But creating self-extracting executables, that clean up after themselves can easily be done by wrapping them in a shell script.

IMO, if low dependencies and small size is really important, you could also just write your script in a low level compiled language (C, Rust, Zig, ...), link it statically (e.g. with musl) and execute that.

Perl is already installed on most linux machines and unless you start delving into module usage, you won't need to install anything else.

Python is more fashionable, but needs installing on the host and environments can get complicated. I don't think it scales as well as Perl, if that's a concern of yours.

Micropython.

I can’t really think of anything that’s less frustrating than sh and ticks all your boxes. You can try TCL but it’s bound to be a shit show. It was painful to use two decades ago.

Perl is a step up in terms of developer comfort, but it’s at the same time too big and too awkward to use.

Maybe a statically linked Python?

I don't have python (or even bash) available in all my systems, and so my goto language for script is usually sh (yes, posix sh), which in all honestly is quite frustrating for manipulating data.

Why are you making it hard on yourself? apt/dnf install a language to use and use it.

Only 5 years ago, everybody would be singing and shouting "perl".

Nowadays it is python that has taken this position (even though Perl is still there and can do so much more).

I honestly love Powershell, but haven't tried the Linux version yet. I only use Bash on linux but it has a load of odd quirks that make it unpleasant to use imo. Can't comment on anything else.

another vote for Lua – lua5.4 is available for all 8 Alpine architectures, tiny installed size (120–200 kB) (and Alpine package only installs two files)

Realistically whatever problems you see in python will be there for any other language. Python is the most ubiquitously available thing after bash for a reason.

Also you mentioned provisioning scripts, is that Ansible? If so python is already there, if you mean really just bash scripts I can tell you that does not scale well. Also if you already have some scriptsz what language are they on? Why not write the function there?

Also you're running syncthing on these machines, I don't think python is larger than that (but I might be wrong).

The smallest footprint for an actual scripting probably will be posix sh - since you already have it ready.

A slightly bigger footprint would be Python or Lua.

If you can drop your requirement for actual scripting and are willing to add a compile step, Go and it's ecosystem is pretty dang powerful and it's really easy to learn for small automation tasks.

Personally, with the requirement of not adding too much space for runtimes, I'd write it in go. You don't need a runtime, you can compile it to a really small zero dependency lib and you have clean and readable code that you can extend, test and maintain easily.

i use mostly python and lua.

No one has mentioned PHP yet? Man, times really have changed.

I still love bash. I'm able to accomplish quite a lot with it. I vote bash.

Technically, you could bundle a Perl script with the interpreter on another system using pp and run the packed version on systems with no installed Perl, but at that point you might as well just use a compiled language.

Not quite a scripting language, but I highly recommend you check out cosmo for your usecase. Cosmopolitan, and/or Actually Portable Executable (APE for short) is a project to compile a single binary in such a way that is is extremely portable, and that single binary can be copied across multiple operating systems and it will still just run. It supports, windows, linux, mac, and a few BSD's.

https://cosmo.zip/pub/cosmos/bin/ — this is where you can download precompiled binaries of certain things using cosmo.

From my testing, the APE version of python works great, and is only 34 megabytes, + 12 kilobytes for the ape elf interpreter.

In addition to python, cosmopolitan also has precompiled binaries of:

• Janet 2.5 MB
• Berry 4.0 MB
• Python 34 MB
• Php 11 MB
• Lua 2.1 MB
• Bash 5.1 MB

And a few more, like tclsh, zsh, dash or emacs (53 MB), which I'm pretty sure can be used as an emacs lisp intepreter.

And it should be noted these may require the ape elf interpeter, which is 12 kilobytes, or the ape assimilate program, which is 476 kilobytes.

EDIT: It also looks like there is an APE version of perl, and the full executable is 24 MB.

EDIT again: I found even more APE/cosmo binaries:

• quickjs (javascript) 2.5 MB
• lisp 20K

I've looked into this a lot actually. There see many options. I'll highlight the pros and cons of each option.

Lua: extremely lightweight, but standard library is lacking, and doesn't include stuff like map or fold. But that would be easy to fix.

Python: thicc standard library, but is not lightweight by any means. There are modifications made to be more shell like, such as xonsh

Rash: based on scheme, very much functional but if you're not used to lisp style, might take a bit to get used to it. This is actually my favorite option. It has a cli interpreter, and really pleasant to use. Cons is... Well it's not very common

You can honestly use any language. Even most compiled languages have a way to run immediately.

If you can, just use Perl. Probably installed on your systems, even the ones without python.

Maybe something like Elvish or Nushell could be worth a look. They have a lot of similarities to classic shells like bash, but an improved syntax and more powerful features. Basically something in between bash and Python. Not sure about disk footprint or general availability/portability though

A scripting language written in Rust would certainly fulfill you requirement of only needing to copy one file since they are always statically linked and you can even statically compile against musl so it will work on any Linux system without needing a correct libc. Maybe check out rhai.

I don't know if it matches your desire for easy install of small disk space, but it might make up for it in other arenas - Ruby is my new-found love when making simple scripts. Being able to mostly emulate the shell integration that bash has by just using backticks to call a shell command is the killer feature in my book.

(Chicken) Scheme.

Schemes have one of the best and most interactive interpreters Is general purpose, allows functional, procedural and OO programming, small disk size and compilable to native executables, Throughout documented and supplemented by years of research, simple setup.

It also is CGI compatible, if necessary.

You might enjoy lua or lune.

guile scheme or Julia

JavaScript through Node.js, or TypeScript through Deno if you like typed languages. They both check all your boxes (just check the size of the executables to make sure that it's what you would consider "small footprint").

Both languages and runtimes are quite popular, so you will find any answers on StackOverflow.

They are both single-executable with little dependencies, and Deno can also compile your scripts to self-contained executables.

As a bonus, both support the vast and extensive NPM package repository where you can find all sort of libraries for even the most complex tasks.

And they work with your favourite IDE or editor, not just syntax highlighting, but also contextual suggestions.

Python.

Just remember to use pyenv for interpreter installation, version and environment management. It's pretty straightforward that way and you have predictability.

Don't ever manually fiddle with the system python and/or libraries or you'll break your system. You should just rely on the package manager for that.

Tried bash, Make, and awk/sed. All hit brick walls. Finally landed on pyinvoke. Two dependencies to install on any new machine. Never had problems. Also, easy to debug and modify as projects evolve.

If you are interested in tiny lisp like languages, this gitlab could be of interest to you.

Full disclaimer, I came across it a few years back as I am the maintainer of arkscript (which will get faster and better in the v4, so that data about it there is accurate as a baseline of « it should be at least this good but can be even better now »).

Perl or python for things likely to already be there. Maybe ruby or PHP if you must. I used to work in groovy a lot but I think it requires the JVM

I would go with Guile, because it is built-in to the Guix Package Manager which is a really good general-purpose package manager.

It ticks several of your boxes:

• has a CLI interpreter
• is a general purpose language, Scheme, amd compliant with revisions 5, 6, and 7 of the language standard
• allows writing in a functional style (it is one of the original functional programming languages)
• small disk footprint, but still large enough to be "batteries included"
• decent documentation, especially if you use Emacs
• simple setup: not so much, unless you are using Guix to begin with. The standard distribution ships with lots of pre-built bytecode files, you need an installer script to install everything.

It also has pretty good libraries for system maintenance and reporting:

• File-Tree-Walk
• A simple web server
• XML parsing

https://nim-lang.org/

Perl would be my candidate for more advanced text handling than what sh can do.

Never used Lua but I think it's fun.

If nothing else works, just learn C/Rust. There's plenty of that on Linux systems, I think you'll be able to manage. Yes, it doesn't meet a lot of your requirements.

You should probably check out Guile.

posix sh + awk for manipulating data?

Why not give (Common)LISP a try?

@gomp I like TypeScript.

I used Python for 15 years or so until they changed from v2 to v3. At that point I realised I couldn't understand my old code because it lacked types, so I got discouraged with that. So rather than learn v3 I stopped using it.

Perl is a disaster. sh is good for shell scripts but let's not stretch it.

TypeScript can use all the JS libraries and runs on node which is supported by all sorts of platforms. Yes there are a few holes in the type safety, so don't do that.

The internet is full of "how to do X in JS". You can read them and add the types you need.

It is possible to wrap something like python into a single file, which is extracted (using standard shell tools) into a tmpdir at runtime.

You might also consider languages that can compile to static binaries - something like nim (python like syntax), although you could also make use of nimscript. Imagine nimscript as your own extensible interpreter.

Similarly, golang has some extensible scripting languages like https://github.com/traefik/yaegi - go has the advantage of easy cross compiling if you need to support different machine architectures.

You could use Ansible for automation just keep in mind it needs python.

Bro seriously just slap pyenv + pyenv-virtualenv on your systems and you’re good to go. They’re absolutely trivial to install. Iirc the latter is not a thing in windows, but if you’re stuck on windows for some reason and doing any serious scripting, you should be using WSL anyways.

@gomp Small footprint? Why not try forth. https://forth-standard.org/

Not sure how big node footprint is but would fit the bill. Would only recommend if you wanna go into web dev career in the future tho 🙃

perl might be on all your systems. It’s kind-of a legacy, but still actively developed. It’s not a great language: it looks like bash scripting on steroids. But if you just need to write some small scripts with a language more powerful than awk or bash, it does the job. If perl isn’t on all of your systems already, then I would choose a better scripting language.

vlang might fit your request pretty nicely. It's a bit patchy in places but mainly stable and gets pretty frequent updates

Looking through the packages available for OpenWRT I would suggest Tcl, Lua, Erlang or Scheme (the latter is available through the Chicken interpreter). Try them out, see what you like.

My go to for most of what you mention is Go, but that’s obviously a compiled language and not for scripting. Or is it - What do you think about https://github.com/traefik/yaegi, which provides an interpreter and REPL for Go? It would let you use a performant and well documented language in a more portable scripting way, but not preclude you from generating statically linked binaries if and when that’s convenient.

That verb doesn't work like that.

Powershell is the superior choice. But if you can't even have bash you probably won't have access.