Not possible to inherit process I/O

[eraserhd]

Hi!

I need to run a command from within clojure that does two things (one essential, one nice) that require the command to have inherited the process I/O.

• The first (nice) one is that it prints color when it detects that it is connected to a terminal.
• The second one is that it will prompt for my SSH passphrase if it needs it when connected to a terminal.

Here's the code that I'd love to replace with conch (but can't right now):

(defn ^:private realtime-output-sh
  "A version of sh in which the child process inherits I/O."
  [& args]
  (let [command-line (take-while string? args)
        {:keys [dir env]} (->> args
                               (drop-while string?)
                               (apply hash-map))
        process-builder (let [pb (doto (ProcessBuilder. command-line)
                                   (.inheritIO)
                                   (.directory (io/file dir)))]
                          (.clear (.environment pb))
                          (doseq [[env-name env-value] env]
                            (.put (.environment pb) env-name env-value))
                          pb)
        process (.start process-builder)
        exit-code (.waitFor process)]
    exit-code))

I'm not sure what the best way to do this would be. Perhaps allowing :inherit as a value for :in, :out, and :err?

[Raynes]

This should definitely be supported by conch. I don't think an :inherit value for everything is the way to go, since you can't only inherit stdin, for example. Probably just need to add an :inherit-io option.

[eraserhd]

I think you're always handling every I/O channel now, right? I think it can be mapped out like so:

1. If any channel has :inherit, call .inheritIO. (Or always call .inheritIO?)
2. Override the channels afterward to be the same as they would have been, except for :inherit ones.

Whether this is a good idea is another question.

I think it might be, because it seems a lot easier to say "Or you can put :out :inherit" than explaining how :inherit-io changes how the other options work.

[Raynes]

That seems reasonable.

[Raynes]

I'd take a PR to add this.