pub fn pipe(from: &EngineCommand, to: &EngineCommand) -> Result<(), EngineError>Expand description
Runs from and to side by side with what from prints going straight into to, the way a
shell’s | does: the bytes pass from one process to the other and never through QCode, so a
home of any size is copied in the memory of a pipe.
Each side’s errors are read on a thread of its own, so a side that says a lot cannot stall the other on a full pipe.
§Errors
When either cannot be started, or either ends in failure: the one that failed, with what it said. When both fail, the reading side is named, because the writing side then had nothing to write.