CODEWITHSUNDEEP
c++fstreameofgetline
naschd
naschd

Reputation: 31

getline and testing EOF at once

I would like to ask about my problem I tried to read Getline and EOF Question but did not help.

Problem is I have no idea where could be mistake here: Is there some problem with used function ( getline or checking EOF ) ?

If there is no text in text.txt file it says there something was found. But I have no idea why or where I made a mistake ...

What I want is: Search for string and if there is no text in txt file I want it to says EOF or something. It still says - even if file is empty - string I was looking for was found in line one , position one - for example

I am puting there code: 

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

using namespace std;

int openFile(void);
int closeFile(void);
int getTime(void);
int findTime();
int findDate();
int stringFind(string);
bool getOneLine(void);

string what;
bool ifound = false;
string foundstring;
string filename ;
fstream inputfile;
string sentence ;
size_t found ;
string foundTime ;
string foundDate ;
bool timeIsHere = false;
bool dateIsHere = false;

int iterTime = 0;
int iterDate = 0;
int line = 0;


int main (void){
    sentence.clear();

    cout << " Enter the file name:" << endl;

    openFile();


    while (getOneLine() != false) {
        stringFind("Time");
    }




    cout << "END OF PROGRAM" << endl;
    system("PAUSE");
    ///getTime();
    closeFile();


    system("PAUSE");
}


int closeFile(void) {
    inputfile.close();
    cout << " File: " << filename <<  " - was closed...";
    return 0;
}

int openFile(void) {

    cout << " Insert file name in program directory or full path to desired file you want to edit:"<<endl;
    cout << " Do not use path with a space in directory address or filename ! " << endl;
    cout<<" ";
    getline(cin, filename);

    inputfile.open(filename, ios::in);

    cout <<" file_state: " << inputfile.fail();
    if (inputfile.fail() == 1) {
        cout << " - Cannot open your file" << endl;
    }
    else cout << " - File was openned sucesfully"<< endl;



    return 0;

}


int stringFind(string what) {
    cout << " I am looking for:" << what << endl;

    found = what.find(sentence);
    if (found == string::npos) {
        cout << " I could not find this string " << endl;

    }
    else if(found != string::npos){
        cout << " substring was found in line: " << line + 1 << " position: " << found + 1 << endl << endl;
        ifound = true;
        foundstring = sentence;

    }

    return 0;


}  



bool getOneLine(void) {
    if (inputfile.eof()) {
        cout << "END OF FILE" << endl << endl;
        return false;
    }
    else{
        getline(inputfile, sentence);
        cout << "next sentence is: "<< sentence  << endl;
        return true;
        }
}

I am newbie and I have no one to ask - personally . I tried to edit While cycle and IF's to make sure that I did not make a serious mistake but I have no idea.

I tried it with for example sample.txt and this file was empty.

Upvotes: 0

Views: 4496

Answers (3)

Arunmu
Arunmu

Reputation: 6901

Correct way to use getline() and EOF checking would be like this:

bool getOneLine(void) {
    if (getline(inputfile, sentence)) {
        cout << "next sentence is: "<< sentence  << endl;
        return true;
    }
    if (inputfile.eof())
        cout << "EOF reached" << endl;
    else
        cout << "Some IO error" << endl;
    return false;
}

Upvotes: 2

Dietmar K&#252;hl
Dietmar K&#252;hl

Reputation: 154045

Always test whether input succeeded after the read attempt! The stream cannot know what you are attempting to do. It can only report whether the attempts were successful so far. So, you'd do something like

if (std::getline(stream, line)) {
    // deal with the successful case
}
else {
    // deal with the failure case
}

In the failure case you might want to use use eof() to determine whether the failure was due reaching the end of the stream: Having reached the end of file and, thus, std::ios_base:eofbit being set is often not an error but simply the indication that you are done. It may still be an error, e.g., when it is known how many lines are to be read but fewer lines are obtained.

Upvotes: 2

Nidhoegger
Nidhoegger

Reputation: 5252

You have one mistake here:

found = what.find(sentence);

You are seeking inside of what for the sentence. If sentence is empty, it will be found.

Change it to

found = sentence.find(what);

You should definitivly learn how to use a debugger. That way you would find such issues pretty fast!

Upvotes: 0

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