# engine.TmuxCommandResult

- **Module:** engine
- **Package:** libtmux
- **Language:** TypeScript
- **Kind:** typealias
- **Source:** https://github.com/libtmux/libtmux-ts/blob/3fe1ca654b81b8cbf4a13b777a001a3298c87a6f/packages/libtmux/src/engine.ts#L101
- **Page:** https://libtmux.org/en/ts/latest/reference/engine-tmuxcommandresult/

What an engine reports back: the process's own exit, not tmux's opinion of it.

A `returncode` of zero and a `signal` of `null` together mean tmux ran and
answered; either one set means it did not finish, and `stderr` says why.