Read strings until end of lines

Question

just to understand how to read correctly, how could i read the next text from file, if i want to read the diferent strings in each line. Each line can have different sizes (1st line could have 3 strings and 2nd line could have 100 strings)

2 //Number of lines
A AS BPST TRRER
B AS BP

I tried in my code something like this, but i dont know how to check if program it's in the end of line.

ifstream fich("thefile.txt");

fich >> aux; //Contain number of line

for(int i=0;i<aux;i++){  //For each line
   string line;
   getline(fich, line);

   char nt;    //First in line it's always a char
   fich >> nt;

   string aux;

   while(line != "\n"){   //This is wrong, what expression should i use to check?
      fich >> aux;
     //In each read i'll save the string in set
   }
}

So at the end, i want that set contains: {{A,AS,BPST,TRRER} {B,AS,BP}}

Thanks.

Use [`std::istringstream`](http://en.cppreference.com/w/cpp/io/basic_istringstream) to parse the line. — πάντα ῥεῖ, Nov 07 '16 at 20:49
Helpful reading: http://stackoverflow.com/questions/7868936/read-file-line-by-line/7868998#7868998 See option 2. — user4581301, Nov 07 '16 at 20:53

score 2 · Accepted Answer · edited May 23 '17 at 12:01

while(line != "\n"){   //This is wrong, what expression should i use to check?

Yes, because the '\n' was removed by the getline() function.

Using std::istringstream it is easy to parse an arbitrary number of words up to the end of the current line:

string aux;
std::istringstream iss(line);
while(iss >> aux) {
    // ...
}

Also note:

fich >> aux; //Contain number of line

will leave you with an empty line read with std::getline() because in this case the '\n' will be leftover from that operation (see Using getline(cin, s) after cin for more detailed information).

Read strings until end of lines

1 Answers1