aus einer Datei Suche nach einem Wort lesen und die gesamte Zeile auf eine andere Datei kopieren

Question

I

1. Eine Katze in Konkurs ging
2. Liste item
3. Etwas eine Datei 1.txt mit den Linien der Worte gibt es

ich für eine Wortliste zu suchen und kopieren 2.txt Listeneintrag die gesamte Zeile auf neue Datei.

Wie mache ich das? danke.

Answer 1

Hier ist, wie Sie das tun:

#include <iostream> 
#include <string> 
#include <fstream> // to read from a file with std::fstream, and to write to a file with std::ofstream 
#include <list> // to use std::list 

int main() 
{ 
    // this list will store all the lines of our file 
    std::list<std::string> myList; 

    std::fstream myFile("1.txt"); 
    if (!myFile) 
    { 
     std::cout << "File open failed." << std::endl; 
    } 
    else 
    { 
     std::string line; 
     while (std::getline(myFile, line)) 
     { 
      myList.push_back(line); 
     } 
    } 
    myFile.close(); 

    // we create a dynamic array(myArray) to store the lines if they contain the word we are looking for 
    std::string * myArray = new std::string[myList.size()]; 
    int count = 0; 

    std::list<std::string>::iterator iter; 
    iter = myList.begin(); 
    while (iter != myList.end()) // we will loop through all the elements of the list(myList) 
    { 
     std::string myString = *iter; 
     // if we find the word we are looking for in our string(myString), we store the string in our array(myArray) 
     if (!myString.find("List")) 
     { 
      myArray[count] = myString; 
      count++; 
     } 
     iter++; 
    } 

    if (count == 0) 
    { 
     std::cout << "The word you are looking for doesn't exit in your file." << std::endl; 
    } 
    else 
    { 
     // if the word has been found then we write the entire line in a new file 
     std::ofstream outFile("2.txt"); 
     if (!outFile) 
     { 
      std::cout << "File open failed." << std::endl; 
     } 
     else 
     { 
      for (int i = 0; i < count; i++) 
      { 
       outFile << myArray[i] << std::endl; 
      } 
     } 
     std::cout << "The word you are looking for was found and a new file has been created." << std::endl; 
    } 

    // don't forget to deallocate the dynamic array (myArray) 
    delete[] myArray; 

    return 0; 
}