inputUtf8

Any input that needs be passed to the process's stdin stream once it has spawned.

block is invoked once and only once. On Jvm/Native, if the process fails to spawn then block is never invoked. On Js there is no way to lazily provide the input, so it is always invoked before spawning the process.

NOTE: block will be invoked from the same thread that Process.Builder.output is called from.

Declaring this will override any Process.Builder.stdin configuration if it is set to something other than Stdio.Pipe.