Reading a CSV file detecting last field in file - c++

Question

I'm trying to read a CSV file and I have three fields that I'm supposed to read in and the very last field is an integer and I am crashing on the last line of the file with stoi function since there is no newline character and I am not sure how to detect when I am on the last line. The first two getline statements are reading the first two fields and my third getline is reading and expecting an integer and my delimiter for that one only is '\n' but this will not work for the very last line of input and I was wondering was there any workaround for this?
My field types that I am expecting are [ int, string, int ] and I have to include spaces with the middle field so I don't think using stringstream for that will be effective
while (! movieReader.eof() ) { // while we haven't readched end of file
stringstream ss;
getline(movieReader, buffer, ','); // get movie id and convert it to integer
ss << buffer; // converting id from string to integer
ss >> movieid;
getline(movieReader, movieName, ','); // get movie name
getline(movieReader, buffer, '\n');
pubYear = stoi(buffer); // buffer will be an integer, the publish year
auto it = analyze.getMovies().emplace(movieid, Movie(movieid, movieName, pubYear ) );
countMovies++;
}

Answer 1

For reading and writing objects one would idomatically overload the stream extraction and stream insertion operators:
Sample csv:
1, The Godfather, 1972
2, The Shawshank Redemption, 1994
3, Schindler's List, 1993
4, Raging Bull, 1980
5, Citizen Kane, 1941
Code:
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <iterator>
void skip_to(std::istream &is, char delim) // helper function to skip the rest of a line
{
char ch;
while ((ch = is.get()) && is && ch != delim);
}
std::istream& eat_whitespace(std::istream &is) // stream manipulator that eats up whitespace
{
char ch;
while ((ch = is.peek()) && is && std::isspace(static_cast<int>(ch)))
is.get();
return is;
}
class Movie
{
int movieid;
std::string movieName;
int pubYear;
friend std::istream& operator>>(std::istream &is, Movie &movie)
{
Movie temp; // use a temporary to not mess up movie with a half-
char ch; // extracted dataset if we fail to extract some field.
if (!(is >> temp.movieid)) // try to extract the movieid
return is;
if (!(is >> std::skipws >> ch) || ch != ',') { // read the next non white char
is.setf(std::ios::failbit); // and check its a comma
return is;
}
is >> eat_whitespace; // skip all whitespace before the movieName
if (!std::getline(is, temp.movieName, ',')) { // read the movieName up to the
return is; // next comma
}
if (!(is >> temp.pubYear)) // extract the pubYear
return is;
skip_to(is, '\n'); // skip the rest of the line (or till eof())
is.clear();
movie = temp; // all went well, assign the temporary
return is;
}
friend std::ostream& operator<<(std::ostream &os, Movie const &movie)
{
os << "Nr. " << movie.movieid << ": \"" << movie.movieName << "\" (" << movie.pubYear << ')';
return os;
}
};
int main()
{
char const * movies_file_name{ "foo.txt" };
std::ifstream is{ movies_file_name };
if (!is.is_open()) {
std::cerr << "Couldn't open \"" << movies_file_name << "\"!\n\n";
return EXIT_FAILURE;
}
std::vector<Movie> movies{ std::istream_iterator<Movie>{is},
std::istream_iterator<Movie>{} };
for (auto const & m : movies)
std::cout << m << '\n';
}
Output:
Nr. 1: "The Godfather" (1972)
Nr. 2: "The Shawshank Redemption" (1994)
Nr. 3: "Schindler's List" (1993)
Nr. 4: "Raging Bull" (1980)
Nr. 5: "Citizen Kane" (1941)