Command Processor

Page last updated 31 Oct 2011, by David Smart. 0 replies command, interface, line

This is a relatively simple command processor. It has a few objectives -

  • Permit flexible IO assignment for serial input and output (serial, USB, etc.).
  • Does not "block" the CPU by waiting for a keystroke (process individual chars and return).
  • Compiles on mbed target and desktop under Visual C++ 2010 Express.

You can read more about the APIs and get the library at CommandProcessor.

Sample in Action

Here's a sample of the program in action, and further below is the source to this sample that makes it happen. 

This program was built Oct  1 2011 15:16:17.

>Help

 Echo   : Echo [1|on|0|off] turns echo on or off.
 Exit   : Exits the program
 Help   : Help or '?' shows this help, 'Help ?' shows more details.
 History: Show command history
 who    : Shows who is logged on, or 'who id' for specifics

>who
who...
>About
This program was built Oct  1 2011 15:16:17.

>

Sample Source Code

And here's the code that makes it happen.

// CommandLine.cpp : Defines the entry point for the 
//                   console application.
//

#ifdef WIN32
#include "stdio.h"
#include "conio.h"
#include "string.h"
#include "assert.h"
#else
#include "mbed.h"
#endif

extern "C" {
#include "CommandProcessor.h"
}

#ifdef WIN32
#else
Serial pc(USBTX, USBRX);
#endif

RUNRESULT_T Who(char *p);
const CMD_T WhoCmd = {
	"who", 
	"Shows who is logged on, or 'who id' for specifics", 
	Who, 
	visible
};

RUNRESULT_T SignOnBanner(char *p);
const CMD_T SignOnBannerCmd = {
	"About", 
	"About this program", 
	SignOnBanner, 
	invisible
};

RUNRESULT_T SignOnBanner(char *p)
{
	puts("\r\nThis program was built " __DATE__ " " __TIME__ ".\r\n");
	return runok;
}

RUNRESULT_T Who(char *p) {
	printf("\r\nwho...\r\n");
	if (*p)
		printf(" Sorry, no help for [%s]\r\n", p);
	return runok;
}

// Provide the serial interface methods for the command processor
#ifdef WIN32
int mReadable() { return _kbhit(); }
int mGetCh() { return _getch(); }
int mPutCh(int a) { return _putch(a); }
int mPutS(const char * s) { return printf("%s\r\n", s); }
#else
Serial pc(USBTX, USBRX);
int mReadable() { return pc.readable(); }
int mGetCh() { return pc.getc(); }
int mPutCh(int a) { return pc.putc(a); }
int mPutS(const char * s) { return pc.printf("%s\r\n", s); }
#endif

int main(int argc, char* argv[])
{
	CMDP_T * cp = GetCommandProcessor();
#ifdef WIN32
	// nothing special for Win32
#else
	pc.baud(921600);
#endif
	cp->Init(
		&SignOnBannerCmd,
		CFG_ENABLE_TERMINATE | CFG_ENABLE_SYSTEM 
		| CFG_ECHO_ON | CFG_CASE_INSENSITIVE,	// options
        50,         // Command Buffer length 
        5,          // History depth # of commands
        mReadable,  // User provided API (kbhit())
        mGetCh,     // User provided API
        mPutCh,     // User provided API
        mPutS);     // User provided API

	// Start adding custom commands now
	cp->Add(&WhoCmd);

	// Should never "wait" in here
	while (cp->Run() == runok)	// run this timeslice
	{
		// do non-blocking things here
		;
	}
	cp->End();	// cleanup
	return 0;
}

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