Thread: CSV Parsing

Using .eof to control a loop is a Bad Idea, inasmuch as it doesn't actually work.

Given a generic CSV file, all you do is look for commas (and new lines, of course). If you're allowed something like 1234,"Lastname, Firstname", 1 with a comma inside quotes that doesn't count then you'll have to be a little more careful.

Originally Posted by tabstop

Using .eof to control a loop is a Bad Idea, inasmuch as it doesn't actually work.

Please elaborate on that. What's wrong with

Code:

filename.getline( buffer, n );
while( !filename.eof() ) {
    ...[do stuff]...
    filename.getline( buffer, n );
}

?

Originally Posted by brewbuck

I have two objections to that:

1. Code duplication of the getline() call leads to brittleness.
2. The use of eof() is simply unnecessary, period.

Code:

while(filename.getline(buffer, n))
{
    ...[do stuff]...
}

I don't doubt you, and I've definitely used that construct in the past, having simply copied it from texts without really understanding what it was doing. Now that I'm actually thinking about what these functions return, I can't find anything that says that [ifstream].getline() or .read() ever return anything other than the stream *this. Presumably they return 0 or NULL when they fail to extract any characters?