Reading in from file gives unexpected output - c++

Question

I am working on reading in from a file and parsing through data from command line argument for homework. And I ran in a wall and I do not know what's the problem, and I hope I could get some advice on what I am missing.
The data file is composed thusly; on the first line, it has number of total lines. For each line after that, it is a line of string separated by | character. I need the '|' character because I want to split my string into substrings.
Here is an example of input file.
3
league of legends|Teemo|Master Yi|Vayne
apple|samsung|smart phone|smart watch
overwatch|d.va|junkrat|Reinhart
Here is my code.
int main( int argc, char* const argv[] )
{
//change string to char* so I can check through each char to see if the
//thing I read in is '|' character.
String Data = (argv[1]);
ifstream fin (Data.c_str());
//check whether the file is open.
if ( !fin.is_open() )
{
cout << "Could not open file" << endl;
}
else
{
int dataLines;
char dataBuffer[100];
//The first integer I read in will be how many lines I will loop through
fin >> dataLines;
//ignore the new line character and do not include it in the count of
//dataLines.
fin.ignore();
//use noskipws so I can recognize whitespaces.
fin >> noskipws >> dataBuffer;
//TEST CODE: COMMENTED OUT FOR NOW.
//cout<<dataBuffer<<endl;
//loop for the number of lines
for(int i = 0; i < dataLines; i++)
{
fin.getline(dataBuffer, 100);
//print the buffer for checking
cout<<dataBuffer<<endl;
}
}
//close the file.
fin.close();
return 0;
}
The result is supposed to look like this.
league of legends|Teemo|Master Yi|Vayne
apple|samsung|smart phone|smart watch
overwatch|d.va|junkrat|Reinhart
The actual result looks like this
of legends|Teemo|Master Yi|Vayne
apple|samsung|smart phone|smart watch
overwatch|d.va|junkrat|Reinhart
The first word that I read in from buffer is gone. "league" is the one that is missing, and I tried to see what the problem is by inserting the test code at the location specified in my code. With the given test code, my output is
league
of legends|Teemo|Master Yi|Vayne
apple|samsung|smart phone|smart watch
overwatch|d.va|junkrat|Reinhart
So the problem is that between reading in the file with noskipws and the forloop that loops over dataLine. Before the forloop my buffer is league. Yet once I enter the loop it is passed that and goes straight to of.
What am I missing here? What could be a possible solution?

Answer 1

Main problem:
fin >> noskipws >> dataBuffer;
Does two things. 1. >> noskipws turns off automatically skipping whitespace, unnecessary because of how OP is reading the stream. 2. >> dataBuffer reads the first word from the stream, in this case consuming the word "league"
Solution: Don't do this.
Other problems:
fin.ignore();
will ignore exactly one character. But what if someone left a nigh-invisible space after the count? Instead use
fin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
to ensure the rest of the line is consumed in its entirity.
char dataBuffer[100];
Why make yourself suffer? Instead use
std::string dataBuffer;
Recommendation:
Use std::stringstream and std::getline to tokenize the lines on '|'
std::stringstream stream(databuffer);
std::string token;
while (std::getline(stream, token, '|')
{
std::cout << token << ',';
}

Answer 2

You do not need the following line:
fin >> noskipws >> dataBuffer;
Tested with g++ 4.8.3 2 on RHEL 7.1

Answer 3

Thanks User 4581301. It reads in the data correctly and split with '|' character. Now I can work on storing the data into classes.
for anyone who may have same problem, this is the fixed up version of code.
int main( int argc, char* const argv[] )
{
String Data = (argv[1]);
ifstream fin (Data.c_str());
if ( !fin.is_open() )
{
cout << "Could not open file" << endl;
}
else
{
int dataLines;
char dataBuffer[100];
fin >> dataLines;
fin.ignore();
for(int i = 0; i < dataLines; i++)
{
while(fin.getline(dataBuffer, 100, '|'))
{
cout<<dataBuffer<<endl;// check to see if it reads in correctly.
}
}
}
fin.close();
return 0;
}