Reading from a file

[fajkovicsasa]

Hi :)

I have some text in a .txt file with some codes that represent a separator to me.
Example :

#?city#!=New York#!100#!
#?city#!=London#!60#!
#?city#!=Tokyo#!10#!

When a user enters a city I need the program to search the .txt file if their is already a town with that name. I am using a while( !txtfile.eof() ) to go thru every line in the txt file. As going through every line I have a variable "name" that is getting the value of the line that the while loop has red. And now i somehow need to ignore the " #?city#!= " and start reading from this point until it reaches the " #! ".

using the indexes isn't gonna work for me at this case.

How can I tell the program - Look you smart ass... Start reading after you hit " #?city#!= "combination of characters and read (including spaces) until you get to the " #! ". :)

[Cubbi]

There are many ways to do that, most of which are generally boiled down to

1) reading the file line by line (e.g. with while(getline(txtfile, line)) -- please don't use "while(!txtfile.eof())"!)
2) examining the line for the character sequence "#?city#!=" followed by the name of the city you're looking for followed by the character sequence "#!"

Here are a couple examples:

#include <iostream>
#include <fstream>
#include <string>
#include <regex>
int main()
{
    std::cout << "Enter the city to search for\n";
    std::string city;
    getline(std::cin, city);
    std::regex re("#?city#!=" + city + "#!.*");

    std::ifstream f("test.txt");
    for(std::string line; getline(f, line); )
        if(std::regex_match(line, re))
            std::cout << "City found in the file\n";
}

or, if you're limited to old C++,

#include <iostream>
#include <fstream>
#include <string>
const std::string prefix = "#?city#!=";
const std::string suffix = "#!";
int main()
{
    std::cout << "Enter the city to search for\n";
    std::string city;
    getline(std::cin, city);

    std::ifstream f("test.txt");
    for(std::string line; getline(f, line); )
        if(line.find(prefix + city + suffix) != std::string::npos)
            std::cout << "City found in the file\n";
}

[fajkovicsasa]

I didn't explain very good.

I have this string :
#?city#!=Zagreb#!70

Zagreb - name of the city
70 - distance to Zagreb from my location

I need to compare the input if it is == to a city already in the txt file. Assuming now that the user has inputted Zagreb I need my program to be able to find it and it will change a certain variable to "true" and after that, with a function I will be needing to get the distance which is 70.