Help reading data from a file

[jbrock31]

Hello everyone. I am trying to work through a programming challenge in my c++ book. I have gotten it to work, but i kind of cheated by looking at the file. I am going to past the entire code so i can be compiled, but the main problem i am having is with reading the last line of a file only.

#include <iostream>
#include <fstream>
using namespace std;

void dispJoke ( fstream& );
void dispPunchLine ( fstream& );

int main()
{
	fstream joke ( "joke.txt", ios::in );
	fstream punch ( "punchline.txt", ios::in );

	if ( !joke )
	{
		cout << "Erorr opening file, joke.txt";
		return 0;
	}
	else if ( !punch )
	{
		cout << "Erorr opening file, punchline.txt";
		return 0;
	}

	dispJoke(joke);
	system("pause");
	dispPunchLine(punch);

	joke.close();
	punch.close();

	return 0;
}
void dispJoke ( fstream& joke )
{
	char data[256];
	joke.getline ( data, 256 );
	while ( !joke.eof() )
	{
		cout << data << endl;
		joke.getline ( data, 256 );
	}
}
void dispPunchLine ( fstream& punch )
{
	char data[256];

	punch.seekg(-35L, ios::end );
	punch.getline ( data, 256, '.' );
	while ( !punch.eof() )
	{
		cout << data << endl;
		punch.getline ( data, 256, '.' );
	}
}

the contents of file punchline.txt are:

asfasdfasdfasdfsdf
asdfasdfsadfsadfsadf
asdfsadfsdfsdf
"I can't work in the dark," he said.

I was trying to use the seekg member function. Am i thinking the right way about this? How do i (if i didnt look at the file) determine where to start printing the data if all i want is the last line, not the "garbage" in this test file. Any advice is much appreciated! Thank you

Jason

[Ancient Dragon]

The while statement is incorrect. The eof() function doesn't work the way you think it does.

while( joke.getline(data, 256) )
{
  // blabla
}

After the above loop finishes data will contain the last line of the file.

[jbrock31]

Thanks for the help.

[WaltP]

AD is correct. Read This