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MiniRobot Language (MRL) - MCP Queue Management Commands
MCP.GetNextCommand / MCP.GetCmd
Retrieve the Next Command from the Queue
Purpose
The MCP.GetNextCommand command retrieves and removes the next command from the MCP server's command queue. This is typically used when implementing custom command processors or when scripts need to manually manage command execution from the queue.
This command is used when:
• Implementing custom command processing logic
• Building command dispatchers or routers
• Inspecting commands before execution
• Implementing custom filtering or validation
Syntax
MCP.GetNextCommand|$$COMMAND_VAR|$$ID_VAR|$$RETURN_VAR
MCP.GetCmd|$$COMMAND_VAR|$$ID_VAR|$$RETURN_VAR
Parameters
$$COMMAND_VAR - The variable that will receive the command string from the queue. Empty if no commands are pending.
$$ID_VAR - The variable that will receive the unique command ID for result correlation. Empty if no commands are pending.
$$RETURN_VAR - The variable that will receive the result code (0 for success, 1 if queue empty, 2 if error).
Return Value
0 - Command retrieved successfully
1 - Queue is empty (no commands pending)
2 - MCP server not running or error
Examples
' Example 1: Basic command retrieval
MCP.GetNextCommand|$$Command|$$CmdID|$$Status
IVV.$$Status!1
PRT.Command [$$CmdID]: $$Command
' Process the command...
ELS.
PRT.No commands in queue
EIF.
' Example 2: Command processing loop
LBL.ProcessLoop
MCP.GetCmd|$$NextCmd|$$NextID|$$Result
IVV.$$Result!0
JMP.ProcessLoopEnd
EIF.
PRT.Processing: $$NextCmd
' Execute and return result...
JMP.ProcessLoop
LBL.ProcessLoopEnd
' Example 3: Command filtering based on prefix
MCP.GetNextCommand|$$Cmd|$$ID|$$Ret
IVV.$$Ret!1
STX.HasPrefix|$$Cmd|MEM.|$$IsMemory
IVV.$$IsMemory!1
' Handle memory command
EIF.
EIF.
Remarks
The MCP.GetNextCommand command removes the command from the queue when retrieved. If you need to inspect the queue without removing commands, use MCP.GetQueueCount to check the queue size.
The command ID returned in $$ID_VAR is used to correlate results when using MCP.ReturnResult. Always preserve this ID if you intend to return a result for the command.
In SYNC mode, commands are retrieved in FIFO (first-in, first-out) order. In ASYNC mode, the retrieval order may vary based on internal scheduling.
MCP.GetNextCommand and MCP.GetCmd are aliases for the same command.
Error Conditions
The command will fail with a parameter error if:
• Any of the required parameters are missing
• Too many parameters are provided
See also:
• MCP.ReturnResult - Return Result to Caller
• MCP.GetQueueCount - Get Queue Count