Find word in a file.

passage.txt

Next to a great forest there lived a poor woodcutter with his wife and his two children. 
The boy's name was Hansel and the girl's name was Gretel. He had but little to eat, and 
once, when a great famine came to the land, he could no longer provide even their daily 
bread.

One evening as he was lying in bed worrying about his problems, he sighed and said to his 
wife, "What is to become of us? How can we feed our children when we have nothing for 
ourselves?"

"Man, do you know what?" answered the woman. "Early tomorrow morning we will take the two 
children out into the thickest part of the woods, make a fire for them, and give each of 
them a little piece of bread, then leave them by themselves and go off to our work. They 
will not find their way back home, and we will be rid of them."

"No, woman," said the man. "I will not do that. How could I bring myself to abandon my 
own children alone in the woods? Wild animals would soon come and tear them to pieces."

word_find.cpp

#include <string>
#include <iostream>
#include <fstream>

int main() {
    std::ifstream inFile("passage.txt");

    std::string needle;
    std::cout << "Enter your keyword: ";
    std::cin >> needle;

    std::string line;

    int line_number = 0;
    int cnt = 0;

    while (!inFile.eof()) {
        std::getline(inFile, line);
        ++line_number;
        int pos = 0;

        while ((pos = line.find(needle, pos)) != std::string::npos) {
            ++cnt;

            std::cout << "Found '" << needle << "' at line " << line_number << ", time " << cnt << ": ";

            // show words before and after the keyword 
            std::string context;

            size_t begin = 0, end_pos = line.length();
            const int padding = 15;

            if (pos - padding > 0) {
                context += "...";
                begin = pos - padding;
            }

            if (pos + needle.length() + padding < line.length()) {
                end_pos = pos + needle.length() + padding;
            }

            int i = begin;

            for (; i < end_pos; ++i) {
                if (i == pos) context += "\033[32m";
                context += line[i];
                if (i == pos + needle.length() - 1) context += "\033[0m";
            }
            if (i < line.length()) context += "...";

            std::cout << context << "\n"; // show the context

            pos += needle.length();
        }
    }
    inFile.close();
    return 0;
}