How to search a document for a string in C ++?

Question

Here is my code:

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

using namespace std;

int main()
{
    int count = 0;
    string fileName;
    string keyWord;
    string word;


    cout << "Please make sure the document is in the same file as the program, thank you!" 
         << endl << "Please input document name: " ;
    getline(cin, fileName);
    cout << endl;

    cout << "Please input the word you'd like to search for: " << endl;
    cin >> keyWord;
    cout << endl;
    ifstream infile(fileName.c_str());
    while(infile.is_open())
    {
        getline(cin,word);
        if(word == keyWord)
        {
            cout << word << endl;
            count++;
        }
        if(infile.eof())
        {
            infile.close();
        }

    }
    cout << count;

}

I'm not sure how to move on to the next word, these are endless loops now ... any recommendation?

Also ... how can I say to print the line that the word was in?

Thanks in advance!

Answer 1

while(infile >> word)
{
    if(word == keyWord)
    {
        cout << word << endl;
        count++;
    }
}

This will do the job. Please read about streams more.

Answer 2

If all you want to do is count the number of keywords in a file, then:

int count = std::count(std::istream_iterator<std::string>(infile),
                       std::istream_iterator<std::string>(),
                       keyword);

If you want to read the words.
But also want to print line numbers, then something like this should work:

std::string      line;
std::ifstream    infile("plop");
int              lineNumber = 0;

while(std::getline(infile, line)) 
{
    ++lineNumber ;
    std::stringstream   linestream(line);
    int hits = std::count(std::istream_iterator<std::string>(linestream),
                          std::istream_iterator<std::string>(),
                          keyword);
    if (hits != 0)
    {
        std::cout << "Line: " << lineNumber << "   Matches(" << hits << ")\n";
    } 
    count  += hits;
} 

Answer 3

while(infile.is_open()) while(infile). eof .

- , . , , failbit (getline ), eof , , . operator bool .

Answer 4

:

getline(cin,word);

if(word == keyWord)
{
    cout << word << endl;
    count++;
}

, cin. infile. :

infile >> word;
if(word == keyWord)
    {
        cout << word << endl;
        count++;
    }

In addition, you must change the condition of the loop. You do not need to check if infile exists . You must check this before starting the cycle. For the loop, you need to check if the eof state is reached or not:

if ( !infile.is_open() ) {
    cerr << "Error while opening file." << endl;
    exit( EXIT_FAILURE );
}    

while( !infile.eof() ) {
    infile >> word;
    if(word == keyWord)
    {
        cout << word << endl;
        count++;
    }
}

And as you can see, now you can get rid of this strange second if you put it inside the loop.
The final step is to introduce the “read ahead” technique: it makes no sense to test if we are not reading anything.

if ( !infile.is_open() ) {
    cerr << "Error while opening file." << endl;
    exit( EXIT_FAILURE );
}    

infile >> word;    
while( !infile.eof() ) {
    if( word == keyWord )
    {
        cout << word << endl;
        count++;
    }

    infile >> word;
}

Hope this helps.