# Socket and servers

Source: https://libtmux.org/en/java/latest/topics/socket-and-servers/

> Select a server socket, check liveness, and detect a replacement daemon.

A tmux server is selected by its Unix-domain socket. Use different sockets for
independent servers, such as a development session and an isolated test server.
Choose the default socket, a named socket (`-L`), or an explicit path (`-S`).

## Naming a server

[`ServerEndpoint.defaultSocket()`](<https://libtmux.org/en/java/latest/reference/io-github-libtmux-serverendpoint-serverendpoint-defaultsocket/>) selects the default socket.
[`ServerEndpoint.namedSocket("work")`](<https://libtmux.org/en/java/latest/reference/io-github-libtmux-serverendpoint-serverendpoint-namedsocket-uymy/>) selects a named socket, and
[`ServerEndpoint.socketPath(path)`](<https://libtmux.org/en/java/latest/reference/io-github-libtmux-serverendpoint-serverendpoint-socketpath-l4dk/>) selects an explicit path.

```java
ServerConfig config = ServerConfig.builder()
        .endpoint(ServerEndpoint.namedSocket("work"))
        .build();
Server named = Server.open(config);
```

Choose either a socket name or a socket path. tmux uses `TMUX_TMPDIR` to
resolve the directory for default and named sockets.

## Is the server actually there?

A server handle does not prove that the target server is running. Use a liveness
check when your program needs to distinguish a live server from an unavailable
socket:

[`Server.isAlive`](<https://libtmux.org/en/java/latest/reference/io-github-libtmux-server-server-isalive/>) returns a boolean.

```java
if (server.isAlive()) {
    server.sessions();
}
```

## Killing a server, and telling two apart

Killing a server ends all its sessions. Use this only for a server your program
owns; for narrower cleanup, kill the session or pane you created.

Call [`server.killServer()`](<https://libtmux.org/en/java/latest/reference/io-github-libtmux-server-server-killserver/>) to stop tmux. [`Server.close()`](<https://libtmux.org/en/java/latest/reference/io-github-libtmux-server-server-close/>) releases the local
connection and leaves tmux running; see [Ownership and cleanup](https://libtmux.org/en/java/latest/topics/context-managers/).

A restarted server can reuse a socket path while having different state. Do
not treat a matching path as proof that a cached object still exists.