Advanced Endpoints

The --listen (or -l) flag is a powerful feature that allows serve to listen on more than just a simple TCP port. You can specify one or more endpoints, including TCP ports, UNIX domain sockets, and Windows named pipes.

This flexibility is useful for inter-process communication or integrating serve into complex development and testing environments.

Specifying Endpoints

Endpoints are specified as URIs. Here are the supported formats:

TCP Port

For listening on a specific TCP port on all available network interfaces. This is the most common use case.

Format: A simple number.
Example:
```
# Listen on port 5000
serve -l 5000
```

TCP Host and Port

For listening on a specific network interface and port.

Format: tcp://<hostname>:<port>

Example:

# Listen only on the localhost interface on port 8080
serve -l tcp://localhost:8080

# Listen on a specific network IP
serve -l tcp://192.168.1.10:3000

UNIX Domain Sockets

For listening on a UNIX domain socket, which is a file on the filesystem used for inter-process communication on POSIX-compliant systems (like Linux and macOS).

Format: unix:/path/to/socket.sock
Example:
```
serve -l unix:/tmp/my-app.sock
```

Windows Named Pipes

For listening on a Windows named pipe, the equivalent of UNIX sockets on the Windows operating system.

Format: pipe:\\.\pipe\<PipeName>
Example:
```
serve -l pipe:\\.\pipe\my-app-pipe
```

Listening on Multiple Endpoints

You can specify the --listen or -l flag multiple times to make serve listen on several endpoints at once. This is useful for exposing your server in different ways simultaneously.

# Listen on port 3000 for network access
# AND on a UNIX socket for local process communication
serve -l 3000 -l unix:/var/run/my-app.sock