Issues with Command Line Parsing in MFC

[KasperD]

Hi.

My very first post here at CodeGuru, so bear with me, if it doesn't comply with all the standards

I'm trying to add a command line interface to an existing MFC application. As of now I can open the application and load a file into the app. using the command line.

I would like the keep that functionality, and add three optional arguments to the command line interface. I've followed the example given by Kirants here: http://www.codeguru.com/forum/showthread.php?t=386406. The "ParseParam" function implemented in the exampel overrides the original ParseParam function, and therefore I'm unable to use the original ParseParam to open the file.

Code example given below:


CommandLineParser.h:

class CommandLineParser : public CCommandLineInfo  
{
	bool clp_reset;
	bool clp_verify;
	bool clp_load;

public:

	CommandLineParser();
	
	virtual ~CommandLineParser();

	bool IsLoad();
	bool IsVerify();
	bool IsReset();

	virtual void ParseParam(const char* pszParam, BOOL bFlag, BOOL bLast);
};


CommandLineParser::CommandLineParser()
{
	clp_load = clp_verify = clp_reset = false;
}

CommandLineParser::~CommandLineParser()
{

}

bool CommandLineParser::IsLoad() 
{
	return clp_load;
}

bool CommandLineParser::IsVerify()
{
	return clp_verify;
}

bool CommandLineParser::IsReset() 
{
	return clp_reset;
}

void CommandLineParser::ParseParam(const char* pszParam, BOOL bFlag, BOOL bLast)
{
        //Arguments could be either -l or --l
	if(0 == strcmp(pszParam, "l") || 0 == strcmp(pszParam, "-l"))
	{
		clp_load = true;
	} 
	else if(0 == strcmp(pszParam, "v"))
	{
		clp_verify = true;
	}
	else if(0 == strcmp(pszParam, "r"))
	{
		clp_reset = true;
	}
}

InitInstance:

BOOL CMyMlvApp::InitInstance()
{
	LPTSTR TempPath;
	char drive[_MAX_DRIVE];
	char dir[_MAX_DIR];
	char fname[_MAX_FNAME];
	char ext[_MAX_EXT];

	...

	TempPath=GetCommandLine();
	if (TempPath[0]=='\"') TempPath++;
	TempPath[strcspn(TempPath," ")]='\0';
	_splitpath( TempPath, drive, dir, fname, ext );
	strcpy(MainPathName,drive);
	strcat(MainPathName,dir);
	SetCurrentDirectory(MainPathName);
	
	
        ...

	// Enable DDE Execute open
	EnableShellOpen();
	RegisterShellFileTypes(TRUE);


	// Parse command line for standard shell commands, DDE, file open
	CCommandLineInfo cmdInfo1;
	ParseCommandLine(cmdInfo1);
	

	// Dispatch commands specified on the command line
	if (!ProcessShellCommand(cmdInfo1))
		return FALSE;

	CommandLineParser cmdInfo2;
	ParseCommandLine(cmdInfo2);

	if(cmdInfo2.IsLoad())
	{
		cout << "IsLoad";
	}
	else if(cmdInfo2.IsVerify())
	{
		cout << "IsVerify";
	}

	cout << "Was it loaded or verified?";

So, to sum it up, I think my issue is that CCommandLineInfo clears the commandline, leaving nothing to be parsed by my CommandLineParser.

How do I work around this?

btw - I'm on Win XP, and using VC++ 6

Best regards
Kasper D.

[VictorN]

Just call the base class method in your CommandLineParser::ParseParam:

void CommandLineParser::ParseParam(const char* pszParam, BOOL bFlag, BOOL bLast)
{
        //Arguments could be either -l or --l
	if(0 == strcmp(pszParam, "l") || 0 == strcmp(pszParam, "-l"))
	{
		clp_load = true;
	} 
	else if(0 == strcmp(pszParam, "v"))
	{
		clp_verify = true;
	}
	....
	else
	{
		CCommandLineInfo::ParseParam( lpszParam, bFlag, bLast );
	}
}

[KasperD]

Wow... Simple and genius solution. This solved my primary issue, but gave me a bunch of new issues, so might return later :P

But for now: Recht schönen Dank Victor!

[VictorN]

You are welcome!

PS: you might also want to look at Paul DiLascia's way to do it here: http://www.microsoft.com/msj/1099/c/c1099.aspx

[KasperD]

Thank you - will look into that Q&A!

[kirants]

This solved my primary issue, but gave me a bunch of new issues, so might return later :P

Cool! I should update the FAQ. Thanks for bringing it up.
Also, curious as to what the new issues are. If related to the FAQ, I would like to fix them.

[KasperD]

Hi kirants!

Okay, at least one of my new issues might be related to the FAQ

The order of arguments in the commandline matters. I would like it to be irrelevant.
e.g. "myAppName -opt1 file.txt" will execute option1, and open file.txt. But "myAppName file.txt -opt1" will execute option1, but will not open the file.

My final problem is a minor one - I would like the program to be able to handle 3 options. e.g. "myAppName -opt1 -opt2 -opt3 file.txt" which is suppose to open the file, and execute the three options. I 've solved this issue by not using an else-if-ladder in the initInstance()

//Kasper D.