C / C++ / MFC

Extracting a string from a tab-delimited file

1-Apr-09 11:57

Jusef Marzbany wrote:
but GetRichEditCtrl().GetModify() allways returns TRUE, even if I set GetRichEditCtrl().SetModify( TRUE )

You use GetRichEditCtrl().SetModify( FALSE ) to reset the modification flag to false - see here[^].

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

SomeGuy6541-Apr-09 11:19

SomeGuy654

1-Apr-09 11:19

I'm trying to create a small function for a program that should extract the data as a string from a column of a tab delimited text file. It seems to be returning an empty string though.

Let me know if you notice what's wrong with this function. Edit: this is VC++

Function:

string split_row(string line, int column)
{
	// The first column would be column 1 for this function. Pass in the string 
	// we want to parse and the column we want parsed. Will return just the string 
	// from the column indicated for this row.

	int c_temp;
	string data;
	int pos;
	const string delimiter = "\t";

	for(c_temp=1; c_temp<=9; c_temp++)
	{
		pos = line.find_first_of(delimiter);
		if (c_temp != column)
		{
			line.erase(0, pos);
		}
		else
		{
			data = line.substr(0, pos-1);
			break;
		}
	}
	return data;
}

If the string "row", below, were to be:

12	test Phone	2009

And we called split_row(row, 2) it should return "test Phone".

Thanks! (sorry for the stupid username)

Re: Extracting a string from a tab-delimited file

Stuart Dootson1-Apr-09 12:05

Re: Extracting a string from a tab-delimited file

1-Apr-09 12:05

This code (changed bits in bold) seems to work with your test data. I suspect you were forgetting that ranges in STL are half-open, i.e. the last character in the range specification isn't part of the range.

string split_row(string line, int column)
{
// The first column would be column 1 for this function. Pass in the string 
// we want to parse and the column we want parsed. Will return just the string 
// from the column indicated for this row.

   int c_temp;
   string data;
   int pos;
   const string delimiter = "\t";

   for(c_temp=1; c_temp<=9; c_temp++)
   {
      pos = line.find_first_of(delimiter);
      if (c_temp != column)
      {
         line.erase(0, pos+1);
      }
      else
      {
         data = line.substr(0, pos);
         break;
      }
   }
   return data;
}

Ought to add a check that pos != std::string::npos, as that indicates no tab, so a possible error condition.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

SomeGuy6541-Apr-09 14:13

SomeGuy654

1-Apr-09 14:13

Works perfectly with your change. Thank you very much!

XML Visual Studio 2003 MFC C++

ScotDolan1-Apr-09 10:59

ScotDolan

1-Apr-09 10:59

I am developing a new software driver. The software will be package into DLL. I would like to store the configuration information for the DLL in a XML file.. I found lots of different XML Parser pojects on Code Project. However, i would prefer to use one from msdn if there is one available. Does anyone have any recomendations.

Scott

Scott Dolan
Jernie Corporation
Engineering & Manufacturing
Software, Hardware, & Enclosures

Re: XML Visual Studio 2003 MFC C++

CPallini1-Apr-09 11:09

Re: XML Visual Studio 2003 MFC C++

1-Apr-09 11:09

ScotDolan wrote:
i would prefer to use one from msdn if there is one available

I bet there is [^].
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

Stuart Dootson1-Apr-09 11:55

1-Apr-09 11:55

If you don't want to use MSXML, there is an alternative[^] from MS that claims to be 'lighter'.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

safe-cast serialization

Member 26037721-Apr-09 7:57

1-Apr-09 7:57

Is there a way in C++ to serialize objects into a char buffer without using reinterpret_cast or c-style casting (and backwards on the other end)? I also don't want to use C++ streams. I don't care how difficult it is.
Thanks

CPallini1-Apr-09 8:09

1-Apr-09 8:09

IMHO your requirements are not wise (why do you want to avoid cast?).
Smile | :)

Member 26037721-Apr-09 9:45

1-Apr-09 9:45

c-style cast is dangerous and hard to find in code. reinterpret_cast is not portable and just as dangerous as c-style. i want a typed way to serialize/deserialize.

CPallini1-Apr-09 10:50

1-Apr-09 10:50

Member 2603772 wrote:
c-style cast is dangerous and hard to find in code.

I don't think so. In your case, moreover, the cast is well scoped.
Smile | :)

Joe Woodbury1-Apr-09 8:40

Joe Woodbury

1-Apr-09 8:40

memcpy

Anyone who thinks he has a better idea of what's good for people than people do is a swine.
- P.J. O'Rourke

grassrootkit1-Apr-09 8:48

grassrootkit

1-Apr-09 8:48

memcpy

Thought about this one but that would require us to cast to void*. He's saying we cannot use c-style casts too.

Joe Woodbury1-Apr-09 8:50

Joe Woodbury

1-Apr-09 8:50

Ah, yes, he wants the MagicalSerialization() function.

Anyone who thinks he has a better idea of what's good for people than people do is a swine.
- P.J. O'Rourke

CPallini1-Apr-09 8:57

1-Apr-09 8:57

Joe Woodbury wrote:
Ah, yes, he wants the MagicalSerialization() function.

That's exactly the point.
Smile | :)

Member 26037721-Apr-09 9:46

1-Apr-09 9:46

If the answer is "It's impossible" that's fine. That's why I'm asking, because I don't know if a solution exists that satisfies my parameters.

Stuart Dootson1-Apr-09 8:53

1-Apr-09 8:53

No casts, C++ streams not necessary[^]

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Member 26037721-Apr-09 9:43

1-Apr-09 9:43

Thanks for the info. I'll take a look at the Boost serialization code to see how it is written.

Stuart Dootson1-Apr-09 9:50

1-Apr-09 9:50

Member 2603772 wrote:
I'll take a look at the Boost serialization code to see how it is written

You can try Smile | :)

It's not the simplest of code!

Boost code can often be difficult to follow...but it is usually good quality in terms of defect escape.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

CPallini1-Apr-09 10:51

convert 32bit to 8bit(256color) bmp?

1-Apr-09 10:51

Member 2603772 wrote:
Boost serialization code to see how it is written.

Possibly you'll find a cast, somewhere.
Smile | :)

Randyqiu1-Apr-09 7:24

Randyqiu

1-Apr-09 7:24

Hello,I'm a new boy here.
Who can give me some entire source code about conventing 32bits to 8bits?My project need such a interface function dealing with a 32bits bmp file and make it a 8bits bmp,even restoring the bmp file.Plesase give me an entire code like this :
void true32to8color(pszFile)
{
.......
}
because I don't have so much time to learn this.
thanks,any help will be appreciated!!!!!!!

Re: convert 32bit to 8bit(256color) bmp?

CPallini1-Apr-09 7:46