# LibTmux.observe_output

- **Module:** LibTmux
- **Package:** LibTmux
- **Language:** Julia
- **Kind:** function
- **Source:** https://github.com/libtmux/libtmux-julia/blob/f3da513be1225d36d5854cd8db5972c01857578e/src/observation.jl#L517
- **Page:** https://libtmux.org/en/julia/latest/reference/libtmux-observe_output/

```
observe_output(f, connection::LibTmux.ControlConnection, args...; kwargs...)

observe_output(
    connection::LibTmux.ControlConnection,
    pane::LibTmux.PaneRef;
    timeout,
    cancel,
    kwargs...
)
```

## Methods

### `observe_output(f, connection::LibTmux.ControlConnection, args...; kwargs...)`

[Source](https://github.com/libtmux/libtmux-julia/blob/f3da513be1225d36d5854cd8db5972c01857578e/src/observation.jl#L715).

### `observe_output` (overload 2)

```julia
observe_output(
    connection::LibTmux.ControlConnection,
    pane::LibTmux.PaneRef;
    timeout,
    cancel,
    kwargs...
)
```

[Source](https://github.com/libtmux/libtmux-julia/blob/f3da513be1225d36d5854cd8db5972c01857578e/src/observation.jl#L527).

Observe raw future pane bytes, not screen images or command completion. The pane must belong to the attached session. Registration precedes enabling output on the request lane; its readiness fence does not reconstruct earlier bytes. Output stays enabled until connection close. Topology changes and tmux pauses require a new baseline; no contiguous-history claim survives them.

```julia
observe_output(connection, pane; capacity=64, max_bytes=1048576, after=nothing,
               timeout=5.0, cancel=nothing)
```

## Parameters

- `f` (`Any`) (for `observe_output(f, connection, args, kwargs)`)
- `connection` (`LibTmux.ControlConnection`)
- `args` (`Vararg{Any}`) (for `observe_output(f, connection, args, kwargs)`)
- `kwargs`
- `pane` (`LibTmux.PaneRef`) (for `observe_output(connection, pane, timeout, cancel, kwargs)`)
- `timeout` (`Real`) (for `observe_output(connection, pane, timeout, cancel, kwargs)`)
  Default: `5.0`.
- `cancel` (for `observe_output(connection, pane, timeout, cancel, kwargs)`)
  Default: `nothing`.