Read particular line from text file using C++

Question

#include <iostream.h>

#include <stdlib.h>
#include <fstream.h>
#include <iomanip.h>
#include <string.h>
#include <conio.h>
int view(void)
{ 
  ifstream in("NewFaculty.txt");

  if(!in) {
    cout << "Cannot open input file.\n";
    return 1;
  }

  char str[255];

  while(in) {
    in.getline(str, 255);  // delim defaults to '\n'
    if(in) cout << str << endl;
  }

  in.close();
  getch();
  return 0;
}

int main()
{
  view();
}

I have this code for retrieving data from text file in C++. Using this code I am getting entire file data as output, like:

          name     address    id
          xxx      hyd       0001
          yyy      hyd       0002

But I need output like only particular line of data by accepting input from keyboard. Need output like:

          name     address    id
          xxx      hyd        0001

Here my input is name. Please anyone help in that way.

What is the input from keyboard (id, name, address, line number)? — sop, Oct 05 '15 at 11:42
Use std::istream::ignore, see details in existed answer: http://stackoverflow.com/a/25012566/492336 — Андрій Каражов, Oct 05 '15 at 12:01
You need to check each line as you read it. First extract the name column and then compare it with your input name to see if they match. If they do, print the line and stop. Otherwise don't print the line and keep going. — Galik, Oct 05 '15 at 12:10

score 0 · Answer 1 · answered Oct 05 '15 at 11:50

I would store the values of each line in a structure like this:

struct RecordLine
{
   std::size_t lineNo; // optional
   std::string name;
   std::string address;
   std::string id;
};

And I would check then the keyboard input, and if so, then I print the line. Be careful to first read the keyboard input, then search in the file. But you can use a class, with methods for reading the line (it would be nicer)

Read particular line from text file using C++

1 Answers1