Extract String From Text 1.0

 main.cpp

#include <iostream>
#include <stdlib.h>
#include <fstream>
#include <string>

using namespace std;

string readLine ( const char* filepath ) {
    ifstream file;
    file.open ( filepath );
    string text;
    if ( file.is_open() ) {
        while ( !file.eof() ) {
            getline ( file, text );
            break;
        }
    }
    file.close();
    return text;
}

int main ( int argc, char* argv[] ) {
    string opt = argv[1];
    if ( !opt.compare ( "-p" ) ) {
        string text = readLine ( argv[3] );
        size_t found = text.find ( argv[2] );
        if ( found != string::npos ) {
            cout << found << endl;
            return 0;
        }
    } else if ( !opt.compare ( "-e" ) ) {
        string text = readLine ( argv[4] );
        cout << text.substr ( atoi ( argv[2] ), atoi ( argv[3] ) ) << endl;
        return 0;
    }
    return -1;
}

附件1