C++, getline, searching through file issue

fugatejeffrey · 02-18-2009, 12:53 AM

Hello World!!!

ok I am taking a my first C++ class and we are suppose to write a very simple program. I have worked my way up to writing to a file, listing the contents of the file, and now i am on to the fun part of searching through the file for a particular word/string.

the program i have made compiles nicely, however, the search function does not provide me with the information i want it to.
I am going to give the portion of code that is giving me the problem. Any help would be appreciated.

Code:

void Book::search()
{
	ofstream inBookFile("book.txt",ios::in);
	string titlesearch;
	string author;
	string date;
	string desc;
	string title;

	if (inBookFile.is_open())
	{
	  cout << "enter the title of a book you wish to search for: \n";
	  cin >> titlesearch;
	  while (! inBookFile.eof())
  	  {
		stringstream stream(title);
		getline(stream,title,',');
		getline(stream,author,',');
		getline(stream,date,',');
		getline(stream,desc,'.');
		if (titlesearch == title)
		{		
			cout << "Title :\t\t" << title << endl;
			cout << "Author :\t\t" << author << endl;
			cout << "Publish Date :\t" << date << endl;
			cout << "Description :\t" << desc << endl;
		}
          }
	}
	else cout << "Unable to open file";
}

BTW. this is a book keeping program. the file it is looking at follows, ordered as title, author, date, description (ignore the garbled nonsense as i was testing the program out)

Code:

red,	john,	a,	a.
red,	chris,	a,	a.
red,	turn,	a,	a.
red,	clown,	s,	s.
blue,	john,	3,	3.
df,	d,	d,	d.
john,	red,	blue,	green.

fugatejeffrey · 02-18-2009, 12:56 AM

P.S. i dont know if i was correct using the stringstream stream() function. but it worked previously for listing all of the books in the file. as shown below

Code:

void Book::display()
{
	ifstream inBookFile("book.txt",ios::in);
	string title;
	string author;
	string date;
	string desc;

	while (getline(inBookFile,title))
	{
		stringstream stream(title);
		getline(stream,title,',');
		getline(stream,author,',');
		getline(stream,date,',');
		getline(stream,desc,'.');
		cout <<setw(20)<< title << setw(23) << author << setw(20)<< left << date << "\n";
	
	}	
}

dwhitney67 · 02-18-2009, 06:16 AM

There's a couple of problems with the code you posted concerning Book::search().

First, the following line:

Code:

ofstream inBookFile("book.txt",ios::in);

should be:

Code:

ifstream inBookFile("book.txt",ios::in);

Note the 'i'. If you want to avoid this mistake in the future, just declare an fstream (don't specify 'o' or 'i').

The next problem is quite simple; you are not reading from the file! I personally do not like checking for eof() because the eof-flag is not set until a read fails. Thus I recommend that you consider setting up your while loop as follows:

Code:

...

string data;

while (getline(inBookFile, data))
{
  stringstream stream(data);
  ...
}