reflex-process
==============
[](https://haskell.org) [](https://hackage.haskell.org/package/reflex-process) [](https://github.com/reflex-frp/reflex-process/blob/master/LICENSE)
Functional-reactive system processes
------------------------------------
Run and interact with system processes from within a [Reflex FRP](https://reflex-frp.org/) application.
Example
-------
The following example uses [reflex-vty](https://github.com/reflex-frp/reflex-vty) to run a terminal application that calls a shell command and displays the result:
```haskell
> {-# LANGUAGE OverloadedStrings #-}
> import Reflex
> import Reflex.Process
> import Reflex.Vty
>
> import Control.Monad ((<=<))
> import Data.Default (def)
> import qualified Data.Set as Set
> import qualified Data.Text as T
> import qualified Data.Text.Encoding as T
> import qualified Graphics.Vty.Input as V
> import qualified System.Process as P
>
> cmd :: P.CreateProcess
> cmd = P.proc "ls" ["-a"]
>
> main :: IO ()
> main = mainWidget $ initManager_ $ col $ do
> exit <- keyCombos $ Set.singleton (V.KChar 'c', [V.MCtrl])
> p <- createProcess cmd def
> stdout <- foldDyn (flip mappend) "" $ _process_stdout p
> grout flex $ boxStatic def $ col $ do
> grout (fixed 3) $ boxStatic def $ text "reflex-process"
> grout (fixed 3) $ text "Press Ctrl-C to exit."
> grout (fixed 2) $ text $ pure $ "Running command: " <> case P.cmdspec cmd of
> P.ShellCommand s -> T.pack s
> P.RawCommand p args -> T.intercalate " " $ T.pack <$> (p : args)
> grout (fixed 1) $ text "stdout:"
> grout flex $ text $ T.decodeUtf8 <$> current stdout
> pure $ () <$ exit
```
Developer environment
---------------------
You can get `ghcid` running for working on the code with the command:
```bash
nix-shell -E '((import ./reflex-platform {}).ghc.callCabal2nix "reflex-process" ./. {}).env' --run ghcid
```