# server.settings.Server.append_array_option

- **Module:** server.settings.Server
- **Package:** libtmux
- **Language:** Rust
- **Kind:** method
- **Source:** https://github.com/libtmux/libtmux-rs/blob/8a648c0894dfffc9303583f753b6c8ae01f2fe76/crates/libtmux/src/server/settings.rs#L341
- **Page:** https://libtmux.org/reference/rs/server-settings-server-append_array_option/

```
server.settings.Server.append_array_option(self, name: &str, index: u32, value: impl Into<OsString>) -> Result<(), Error>
```

Extend the value already at one index of an array option.

Appends to that index's value rather than adding an entry, which is
what tmux's `-a` does here.

# Errors

Returns an error when tmux refuses the option name or the value.