mystring class getline() function

[grcunning]

I've finished and turned in my myString class. The prof gave us a test harness to run against our class, so we can make corrections and turn it back in. Everything else works fine, but I have come across a problem with my getline() function. It seems to work fine when reading from the keyboard, but doesn't work when reading from a file.
This is what the function is right now.

void getline(std::istream& ins, mystring& target)
{
	mystring tempstring;
	char ch;
	
	while (ins.peek()!='\n')
	{
		ins.get(ch);
		tempstring+=ch;
	}
	target=tempstring
}

The file it reads from is simple, just two lines:

This is line 1.
This is line 2.

This is the code he uses to read the file with getline():

	// Open the file for the first set of tests
	fin.open("mystringtest.txt");
	fin.clear();

	if(fin.fail()) {
		cout << "Problem opening \"mystringtest.txt\"" << endl;
		cout << "file i/o tests skipped." << endl;
	} else {
		// Testing fin >> into an empty string
		while(fin >> s1) {
			cout << s1.toString();
		} // while
		fin.close();

		cout << "\n8.5\tTesting getline(fin,s1);" << endl;	
		fin.open("mystringtest.txt");
		fin.clear();	// clear eof flag since open doesn't do so automatically

		while(!fin.eof()) {
			getline(fin,s1); 
			cout << s1.toString();
		} // while
	} // if 

The problem is that it reads in the first line just fine, then goes into a continuous loop(It never gets to the second line, which I think is because of the newline character at the end of the first line. If I put a cin.ignore(1,'\n') at the end, it outputs the first line, clears the newline character, then reads in the second line just fine, then sits there. I think in this case, the ignore also clears the 2nd newline of the file, and it never hits the EOF.
Any ideas?

[firedraco]

Don't use peek(), instead, just use get() like you are doing and check if ch is a '\n'.

You could also simply read in up to and including the '\n' to your string, then just replace the '\n' with a '\0'.

[grcunning]

This is what I changed it to:

void getline(std::istream& ins, mystring& target)
{
	mystring tempstring;
	char ch;
	ins.get(ch);
	while (ch!='\n')
	{
		tempstring+=ch;
		ins.get(ch);
	}
	target=tempstring;
}

It reads in both of the lines perfectly, but after returning, and after the test harness prints out the string (with s1.toString()), it just freezes. When stepping through it in the debugger, after the tostring(), it goes back to the while (!fin.eof())and then I can't step any more, even though VS says the app is still running. Is there a problem when I get(ch) the final '\n' that the while loop doesn't detect eof?

[guestgulkan]

you should check for eof in your code otherwise you will end up in an ininite loop.

void getline(std::istream& ins, mystring& target)
{
	mystring tempstring;
	char ch;
	ins.get(ch);
	while (ch!='\n' && !ins.eof()) //check for end of file
	{
		tempstring+=ch;
		ins.get(ch);
	}
	target=tempstring;
}

[grcunning]

wooohoo, works perfectly!
Thanks so much