Help translating from VB

[brenaaro]

Can someone help me translate this from VB to C++?

' Visual Basic version
Public Function LineTrim(Expression As String) As String
'Remove trailing CRs and LFs
    Dim sReturn As String
    Dim sCheck As String
    
    sReturn = Expression
    
    sCheck = Right(sReturn, 1)
 
    Do While (sCheck = Chr(10)) Or (sCheck = Chr(13))
        sReturn = Left(sReturn, Len(sReturn) - 1)
        sCheck = Right(sReturn, 1)
    Loop
    
    LineTrim = sReturn
    
End Function

and now the C++ version, which will be in a DLL for VB

LPCSTR LineTrim(LPCSTR *Expression)
{
     // I dont want to alter the original string,
     // so I need to declare this return value correct?
     LPCSTR ReturnVal;

     // How can I move the pointer to the end of the LPCSTR
     // without looping through it until '/0'

     // How can I check for the ascii value of the current char,
     // and shorten the string if it's CR or LF?

     LineTrim = ReturnVal;
}

[nabeels786]

LPCSTR LineTrim(LPCSTR line) {
	char *tmp =  new char[strlen(line)];

	strcpy(tmp,line);
	strrev(tmp);

	while(*tmp==char(10) || *tmp==char(13)){
		*tmp++;
	}
	
	return strrev(tmp);
}

I think if you wanted to return a string to VB it had to be a BSTR, I'm not sure though

[brenaaro]

Ok thanks! I'll give it a try.

[Daok]

if I can remember vb(so long time didn't program on vb), but I think that it already have the function Trim() in vb...

[brenaaro]

Yeah it does, but it only trims spaces. I needed something that would trim carriage returns and line feeds as well..

While I'm here, is there a C++ function to get the Hexadecimal value of an expression?

Say I wanted the Hex value of "a", or of the number 72. Is there an existing method I can call?

[parksie]

You can use itoa, and give a radix of 16

PS: How you return a string to VB is tricky because you can't deallocate the C++ memory within VB...

BSTR is the way to go, I believe.

[nabeels786]

yup its BSTR

BSTR LineTrim(BSTR line) {
	char *tmp =  new char[strlen((LPCSTR)line)];

	strcpy(tmp,(LPCSTR)line);
	strrev(tmp);

	while(*tmp==char(10) || *tmp==char(13)){
		*tmp++;
	}
	
	return (BSTR)strrev(tmp);
}

[Daok]

Originally posted by brenaaro
Yeah it does, but it only trims spaces. I needed something that would trim carriage returns and line feeds as well..

While I'm here, is there a C++ function to get the Hexadecimal value of an expression?

Say I wanted the Hex value of "a", or of the number 72. Is there an existing method I can call?

http://www.vbforums.com/showthread.p...hreadid=199715

[jim mcnamara]

You are creating a memory leak -
Try (this is C)

unsigned int  in(char, char *);

char *rtrim(char *s){ // remove trailing blanks
     register char *buf;
     char *remove = " \n"; // change this to alter what gets whacked
     if(*s){
       	for(buf=s;*buf;buf++);
       	for(buf--;in(*buf,remove)&&(int(buf)>=(int)s; buf-- )
	  	*buf=0x00;
     }
     return s;
}
unsigned int in(char ch,const char *test){
         unsigned int result=1;        
         register char *buf;
         for(buf=test;*buf,result;buf++) result=(ch==*buf); 
         return result;
}

[CornedBee]

corrected version of naabels code:

BSTR LineTrim(BSTR line) {
	wchar_t *tmp =  new wchar_t[wcslen((LPCWSTR)line)];

	wcscpy(tmp,(LPCWSTR)line);
	wcsrev(tmp);

	while(*tmp==wchar_t(10) || *tmp==wchar_t(13)){
		tmp++;
	}
	
	BSTR ret = SysAllocString(wcsrev(tmp));
	delete [] tmp;
	return ret;
}

Avoids memory leaks and problem with incorrect usage of char.

[brenaaro]

Great work guys, thanks for all the code. I never would have figured it out by myself..well..maybe I would but it would have taken months!

[nabeels786]

Originally posted by CornedBee
corrected version of naabels code:

BSTR LineTrim(BSTR line) {
	wchar_t *tmp =  new wchar_t[wcslen((LPCWSTR)line)];

	wcscpy(tmp,(LPCWSTR)line);
	wcsrev(tmp);

	while(*tmp==wchar_t(10) || *tmp==wchar_t(13)){
		*tmp++;
	}
	
	BSTR ret = SysAllocString(wcsrev(tmp));
	delete [] tmp;
	return ret;
}

Avoids memory leaks and problem with incorrect usage of char.

ah coolio..wheres the memory leaks? i wanna get this right

[CornedBee]

BSTR is more than just a cast.
a) It's UNICODE, so you can't simply copy it to a ANSI string (that's why I used wchar_t).
b) It's counted, so you should use SysAllocString, which creates a completly valid BSTR for you.
c) You still don't free the memory allocated by new. And if you don't, no one else will (surely not VB).
d) *tmp++; don't dereference here.

BSTR LineTrim(BSTR line) {
	char *tmp =  new char[strlen((LPCSTR)line)];

	strcpy(tmp,(LPCSTR)line);
	strrev(tmp);

	while(*tmp==char(10) || *tmp==char(13)){
		*tmp++;
	}
	
	return (BSTR)strrev(tmp);
}