RCPd

RCPd is an acronym that may refer to multiple software projects, and there is no single, universally adopted definition. The most common interpretation is a daemon that implements a Remote Control Protocol (RCP) to allow clients to control devices or software remotely. Because the term is used by different developers and vendors, individual RCPd implementations can vary in features, interfaces, and security models.

Typically, an RCPd runs as a background service on Unix-like systems and listens on a network port for incoming connections. It authenticates clients, parses received commands, and translates them into device-specific actions or software operations. Responses are sent back to the client, enabling synchronous or asynchronous control. Data formats and command sets vary across implementations; some use simple text commands, while others employ structured formats such as JSON, XML, or compact binary frames.

Security and configuration are important considerations. RCPd deployments may support encryption (for example, TLS), authentication mechanisms, and access control lists to limit who can issue commands. Configuration is commonly handled via file-based profiles or service configuration tools, with logging to system logs for auditing and troubleshooting.

Use cases for RCPd-like daemons include controlling home entertainment systems (playback, volume, input switching), managing networked devices and servers, and coordinating actions in IoT or automation environments. Because there is no single standard, interoperability between different RCPd implementations is limited; software relying on RCPd typically requires a matching client and server pairing.

See also: Remote Procedure Call, daemon, networked control protocols.