daemon-command-extension

Adding a New Daemon Command

Follow these steps to extend the daemon's capabilities with a new command.

1. Define Constants

Open daemon/include/Constants.h and add definitions for your command and any unique arguments.

#define COMMAND_MY_NEW_ACTION "myNewAction"
#define COMMAND_ARG_MY_PARAM "myParam"

2. Implement the Handler

In daemon/src/mainCommand.cpp, implement a handler function. The function must take a const json & and return a CmdResult.

CmdResult handleMyNewAction(const json &command) {
    string param = command[COMMAND_ARG_MY_PARAM].get<string>();
    // ... implement logic ...
    return CmdResult(0, "Action successful: " + param + "\n");
}

3. Register the Command Signature

In daemon/src/mainCommand.cpp, locate the COMMAND_REGISTRY array and add your command's signature (name and required arguments).

const CommandSignature COMMAND_REGISTRY[] = {
    // ...
    CommandSignature(COMMAND_MY_NEW_ACTION, {COMMAND_ARG_MY_PARAM}),
};

4. Register the Dispatcher Handler

In daemon/src/mainCommand.cpp, locate the COMMAND_HANDLERS array and map your command string to its handler function.

static const CommandDispatch COMMAND_HANDLERS[] = {
    // ...
    {COMMAND_MY_NEW_ACTION, handleMyNewAction},
};

5. Build and Test

Rebuild the daemon and test your new command using the terminal d (or daemon send) command.

bd
d send myNewAction --myParam "hello"

[!TIP] Use CmdResult(0, ...) for success and CmdResult(1, ...) for errors. The second argument is the response string sent back to the client.