Fang, the CLI Starter Kit

[csomar]

I’ve been maintaining rust-starter[!] for quite sometime now. It is kind of the equivalent of fang but for Rust. It uses Clap which is the equivalent of Cobra; though I don’t think Clap has the same kind of fancy output?

Throughout these years, I have found that cross-compiling is the most challenging part of creating a CLI. When you are building a web back-end, you control the execution environment (usually linux). For CLIs, your users could be on Linux, macOS or Windows. You need to get three x2 binaries (so a total of 6) to have a fair coverage.

I’ve tried cross, but for Windows and macOS you need licenses. There is no straightforward way to give your users Docker images and have them running in a few commands. You can compile on GitHub action machines, but that’s a very slow feedback loop. I wonder if things are better in Go land.

!: https://github.com/rust-starter/rust-starter

[neomantra]

Golang itself bundles a toolchain and can cross compile to a many target OSes and architectures. I use Goreleaser [1] to create GitHub releases, Homebrew packages, Docker images, and Linux packages. Goreleaser Pro can also create MSI packages.

ETA since I just saw Christian chime in: the Goreleaser author works at Charm.sh =)

[1] https://goreleaser.com

[christianrocha]

I feel your pain. That said, cross compiling from Go is pretty trivial, as long as everything is pure Go, which it most often is. That’s one if the reasons we invested in jt.

(Hello from Charm! I’m one of the authors of this library.)

[threemux]

Wow TIL cross compilation is a bit of a pain in Rust. I assumed it was as easy as Go. I can confirm as long as you're using pure Go (no cgo), it's as easy as setting $GOOS and $GOARCH appropriately.

[rmac]

I looked into how rust does does it for rustup, and they have a pretty amazing set of gh actions to build for their architectures, I can't find the GH link now tho

for speed you can look for vendors like https://depot.dev/

[mootoday]

This is great, lots I learned by looking at your code and the dependencies you use!

I started a similar thing, although not as feature-rich as yours. My goal was to follow CLI best practices and add all the boilerplate one needs to build a Rust CLI.

https://github.com/mootoday/cli-template

[masfuerte]

I configure github actions to build each version in its natural habitat.

Though my motivation for this was getting the builds off my machine. I didn't want to be shipping binaries I had built locally.

[johnisgood]

I just ran across "gum"[1] from charmbracelet which I intend to use! I just want to replace dialog. I came across whiptail, too, but gum seems nicer.

They have a TUI framework, too, among a lot of other related things. Some of their projects are Go libraries, some are a CLI tool, such as gum.

[1] https://github.com/charmbracelet/gum

[nodesocket]

Gum looks awesome. Gonna keep it in-mind next time I need to write a shell CLI.

[bbkane]

It would be really cool if Fang could generate a TUI form for your app with https://github.com/charmbracelet/huh (by the same org). Is something like that on the roadmap?

Similar work: https://github.com/chriskiehl/Gooey and https://github.com/Sorcerio/Argparse-Interface

I've wanted to do TUI form generation for my own CLI framework since 2023 ( https://github.com/bbkane/warg/issues/71 ), but I still haven't gotten around to it

[jmsdnns]

This is awesome! Love the work the charm bracelet team is doing.

[christianrocha]

Thank you for the very kind words. Hello from Charm!

[jonpalmisc]

Stubborn complaint (and maybe a hot take): I dislike CLIs that try to be overly pretty. I don't receive any tangible benefit as the user from the "fancy" (their words) help output. I'd much rather simple plain text output that looks like all the other tools I already use.

[arp242]

Alignment (and maybe bold text for some things) is all you need in >95% of cases, IMHO.

One of the downsides of a lot of these tools is that's exactly what they don't do well: many things don't align or wrap nicely.

For example, here's a comparison of this fang library vs one where I just raw-dogged the usage text: https://imgur.com/a/QWh9TLD – the nice alignment does a lot more than colours. Especially for larger programs with a bunch of flags it can be such a pain. For example from an otherwise quite nice tool: https://imgur.com/a/RELL9Gk – you just completely lose any "overview".

I did spend some time on some better tooling to improve all of this, because manually writing these isn't super-fun either, but not so straight-forward to do well (or at least: not in a way that I like).

[anitil]

I like colour in a tool like 'bat' or 'jless' where it helps me visually scan, but other than that I'd agree with you

[joshka]

As a counter argument, not putting color in help usage text leaves a large amount on the table for readability. The reasonable compromise for those that disagree with this is to set the NO_COLOR environment variable. This should be respected by most things which do use color (and if it's not, that's a bug).

[quotemstr]

> overly pretty

"bling" is the word you're looking for. It's just a fashion. Fashion is famously cyclic, and we're just in a high-ornamentation part of the cycle. Eventually, restraint will become fashionable again.

[guappa]

And they often don't check the terminal so if you pipe them or run on a serial terminal they break horribly.

[assbuttbuttass]

agreed, plain text is more scriptable too. Let me pipe it into awk!

[aranw]

It's probably more accurate to say it's a Go Cobra CLI Starter Kit rather just a generic CLI Starter kit. I personally find Cobra bit OTT and bloated and try to avoid it where I can but this could be a nice starter point for my own similar library to suit my needs

[RSHEPP]

Just re-wrote an internal CLI to urfave from custom, but having issues with v3 autocomplete scripts. Might just take the time to switch over to cobra and use this.

[syvolt]

I think kong[1] is better than both options although cobra is by far the most popular. Might be worth a look.

Definitely won't look as pretty as the parent project though but I prefer kong in terms of the actual code you need to write.

[1] https://github.com/alecthomas/kong

[Cthulhu_]

That's pretty neat, although it's little more than a coloring wrapper around Cobra. That said, I wrote a small tool for a hackathon and just dropped this in for a bit of whimsy.