babashka.process, a small wrapper around java.lang.Process. WIP. Feedback welcome: https://github.com/babashka/babashka.process

Cool! I like your design for stdout handling: {:out :inherit} vs {:out :string} . In my usages of ProcessBuilder, I have found that I sometimes need to capture stderr to a string. Your process kind of implies it can do that, but I don’t think that it is implemented yet.

That's really cool - I have a bunch of hairy ECS deployment scripts and moving to bb will simplify a lot of stuff

Rewrite-cljc scripts have an internal shell/command based on one of your examples I think. Here’s the https://github.com/lread/rewrite-cljc-playground/blob/3aa4741a773ccd329c350208c50a83b1e8ce9671/script/helper/shell.clj#L60.

@lee Added support for {:err :string}

Also updated the README

@borkdude is as fast as ⚡!

I realize you can also just use slurp instead of those StringWriter stuff :)

I also like your naming: process is more apt that something like shell or shell-command.

Slurpy cool! I guess that stderr is never binary… is stdout ever binary?

can be yeah

in that case you can use

to copy it to a file or whatever

clojure.java.shell has some stuff around this: https://github.com/clojure/clojure/blob/fe0cfc71e6ec7b546066188c555b01dae0e368e8/src/clj/clojure/java/shell.clj#L93

we can support :out-enc as well

yeah and your design is extensible you could {:out something-else} if the need arises.

yeah

Oh just re-reading my version, and I did a little https://github.com/lread/rewrite-cljc-playground/blob/3aa4741a773ccd329c350208c50a83b1e8ce9671/script/helper/shell.clj#L21.

I remember doing that too somewhere

I'll make an issue for it

I think this will make a very handy addition to babashka! I remember when first translating a bash script to babashka thinking cool, cool, cool - then, oh but that’s a bit of a big fn to just call a process, then, cool, cool, cool.

@lee fwiw, this was my fix for Windows: https://github.com/borkdude/babashka.curl/blob/53b5b9d98f2e594384f628b0deee76b53bea5062/src/babashka/curl.clj#L20

Oh, I think you have helped me see that my version is adding too many backslashes maybe.

With clj-kondo I applied the same: https://github.com/borkdude/clj-kondo/blob/de925fa93ede2672cba5de4d36cfd3c21e0a7f72/test/clj_kondo/test_utils.clj#L110

Maybe I can get rid of this workaround once and for all with babashka.process

That would be awesomeness. Lib will be handy for regular Clojure too, no?

Of course yes

It's available right now, with the risk of things still changing :)

I think I will likely be an early adopter.

I'm still a bit unsure about some things: maybe :out :string and :err :string should be the default. And when it is, maybe :exit should be the exit code directly, not a future / delay with an exit code. This is also how babashka.curl works. Also maybe throw with the contents of :err if :exit is non-zero, unless :throw is false.

yeah i like that paradigm

I’m a sample size of 1, but when scripting I only occasionally capture output to strings. So :out and :err defaulting to :inherit would make more sense for me. My bash scripts always start with set -eou pipefail meaning that when anything goes wrong, I’d like my script to fail, so a default of throwing on error in babashka would make sense for me. That said, if I don’t like the defaults, I can very easily write a little wrapper fn that changes them.

@lee I'm willing to change it later, based on more feedback

Ya, I am totally happy with whatever you choose.

Added this now: Both :in and :out may contain objects that are compatible with :

clojure
user=> (with-out-str (process ["cat"] {:in "foo" :out *out*}))
"foo"

user=> (with-out-str (process ["ls"] {:out *out*}))
"LICENSE\nREADME.md\ndeps.edn\nsrc\ntest\n"

neat!

Probably exit code should also be wrapped in a future when :inherit is used. Since this is getting fairly complex, it might be better to just always wrap it in a future. Or maybe it should be an option.

Made it an option: :wait false which returns the exit code in a future.

Also came up with this (could not sleep because of the heat): Forwarding the output of a process as the input of another process can also be done with thread-first:

(-> (process ["ls"])
    (process ["grep" "README"]) :out)
"README.md"