C / C++ / MFC

<br />
bool ReadPort()<br />
{<br />
     long int dwSize = 0;<br />
     bool hResult = false;<br />
     std::string sb = "";<br />
     DWORD dwEventMask;<br />
<br />
     if(!SetCommMask(hComm, EV_RXCHAR)) /* Setting Event Type */<br />
	 {	<br />
        return hResult;<br />
     }<br />
<br />
	if(WaitCommEvent(hComm, &dwEventMask, NULL)) /* Waiting For Event to Occur */<br />
	{<br />
		char szBuf[1024];<br />
		DWORD dwIncommingReadSize;<br />
<br />
		do<br />
		{<br />
			if(ReadFile(hComm, &szBuf, 1024, &dwIncommingReadSize, NULL) != 0)<br />
			{<br />
				if(dwIncommingReadSize > 0)<br />
				{<br />
					dwSize += dwIncommingReadSize;<br />
				    sb.append(szBuf);<br />
				}<br />
				hResult = true;<br />
			}<br />
<br />
			else<br />
			{<br />
				unsigned long error = ::GetLastError();<br />
				hResult = false;<br />
				printf("the error while reading error is %dl\n", error);<br />
				break;<br />
			}<br />
		} while(dwIncommingReadSize > 0);<br />
<br />
		*readData = new char[dwSize];<br />
		strcpy(*readData, sb.c_str());<br />
		return hResult;<br />
	}<br />
    else<br />
    {<br />
		return hResult;<br />
    }<br />
<br />
}<br />

George_George wrote:

For trim, I use find first/last not of space technique, and for toupper/tolower, I always change them manually by adding some value to 'a' to form 'A' or vice versa.

My question is I want to find some best practices to implement them (one reason is I think my private implementation may be error prone and the other reason is I am not sure whether there is existing APIs which could be utilized) and comment about my current implementation issues.

std::string Str = "nibu babu thomas";
std::transform( Str.begin(), Str.end(), Str.begin(), toupper );
std::cout << Str;

George_George wrote:

How about trim? No built-in APIs?

void Trim( const std::string& StrToTrim, std::string& TrimmedString )
{
   std::string::size_type First = StrToTrim.find_first_not_of( ' ' ); // Find first non space char
   std::string::size_type Last = StrToTrim.find_last_not_of( ' ' ) + 1; // First first last non space char
   TrimmedString = StrToTrim.substr( First, Last - First ); // Return substring
}

int main()
{
   std::string StrToTrim = "   32  Nibu babu thomas   2342 2 23 3    ";
   std::string TrimmedString = "On return will hold trimmed string";
   Trim( StrToTrim, TrimmedString );
   
   return 0;
}

George_George wrote:

Do you have any reference documents?

George_George wrote:

1.

No document which describes all possible exceptions may be thrown by a specific STL function, like string.substr?

2.

"the files exception and stdexcept" -- yes, but for a specific STL function like string.substr, how do you check all possible exceptions may be thrown by looking at the file? Smile

void Trim( const std::string& StrToTrim, std::string& TrimmedString )
{
   // Find first non whitespace char in StrToTrim
   std::string::size_type First = StrToTrim.find_first_not_of( ' ' );
   // Check whether something went wrong?
   if( First == std::string::npos )
   {
      First = 0;
   }

   // Find last non whitespace char from StrToTrim
   std::string::size_type Last = StrToTrim.find_last_not_of( ' ' );
   // If something didn't go wrong, Last will be recomputed to get real length of substring
   if( Last != std::string::npos )
   {
      Last = ( Last + 1 ) - First;
   }

   // Copy such a string to TrimmedString
   TrimmedString = StrToTrim.substr( First, Last );
}