Function has a bug under only 1 condition

[int main]

Hello,

I am munipulating a text file for my c++ course.

The software replaces characters in a text file.
The only problem is that if I replace a number óf characters beginning with the first character in the file, the output gets distorted.

In the textfile

123456789012345678901234567890
123456789012345678901234567890
123456789012345678901234567890

gets changed to (The * stands for a space)
**********12345678901234567890
123456789012345678901234567890
123456789012345678901234567890

but on the console the thing is shown as

12345678901234567890
123456789012345678901234567890
123456789012345678901234567890

this is the function to read the file to the screen:

void Daten::lesen()
{	
	ifstream MyIfstream(DateiName);
	char ch;
	MyIfstream >> ch;
	while (!MyIfstream.eof())
	{
		cout << ch;
		ch = MyIfstream.get();
		
	};
};

Why do I not get the 10 spaces printed to the console?

int main

[jpeg]

Is there another function that changes the file? We would need to see that one as well to compare.

[int main]

I have the code at home so I will provide it this evening (CET).

The thing is, though, that the file is changed correctly. If I open it with WordPad, the spaces are in the correct location and the formatting is as it should be. Only on the console-"printout" the first spaces somehow get lost .

int main

[int main]

Here is the code of the function which manipulates the file.

void Daten::manipulate(int Pos, int Amount, char Overwrite)
{
	fstream MyFstream(FileName);
	Pos = Pos - 1; // c++ starts counting with 0
	char ch;
	for (int i=0;i<Pos;i++)
	{
		ch = MyFstream.get();
		if (MyFstream.eof()) 
		{	// end of function if position is outside the file
			cout << endl << "Position does not exist.";
			cout << endl << endl;
			return;
		};
		if (ch=='\n') 
		{	// if it's a '\n' then skip the two chracters and adjust the position
			Pos +=2; 
			i +=1;
		};
	};

	for (int i=Pos; i < (Pos+Amount);i++)
	{
		MyFstream.seekp(i);
		ch =MyFstream.get();
		if (MyFstream.eof())
		{	// if too many characters are to be replaced
			cout << endl << "Cannot overwrite enough characters.";
			cout << endl << endl;
			return;
		};
		if (ch == '\n')
		{	// same as above
			Amount +=2;
			i +=1;
			continue;
		};
			MyFstream.seekp(i);
			MyFstream << Overwrite;
	};
};

int main

[Duthomhas]

I have had to figure this kind of thing out myself. I think (without having compiled and used your code) that it is one of those obnoxiousnesses of istreams.

The >> is a formatted input operator, which by default skips all whitespace. If you want to keep whitespace, you'll have to add
MyIfstream >> noskipws;

I've learned that dealing with iostreams has a lot of 'gotcha's. Hope this helps. :-)

[int main]

Yes, it helped.

Thank you very much.

But how do I find such things out? Where do I find that?

int main