C++ function unable to another function and ends automaticly

Question

So I was making a file editor using c++ and it has 3 functions and it needs to call each other to work properly.But When code tries to call other functions it end abnormly .

I tried changing the order of functions but it does nothing.It will compile properly without warnings

it needs output the contents of the file.


#include <iostream>
#include <fstream>
#include <bits/stdc++.h>
#include <string>
#include <iomanip>
#include <unistd.h>
#include <sstream>
using namespace std;/* std */

  /* data */
 char buffer;
 std::string fname;

 int reader(){
   std::ifstream readfile;
   readfile.open(fname.c_str());
   readfile>>buffer;
   std::cout << buffer<< '\n';
   int write();
   }
int options(){
  cout << "************************"<< '\n';
  cout << "* Starting File editor *"<< '\n';
  cout << "************************"<< '\n';
  cout << "*    Enter Filename    *"<< '\n';
  cin >>fname;
  cout << "Opening File"<<fname<< '\n';
  int reader();
  std::cout << buffer<< '\n';
   }
int write(){
  cout << "writing to file  " << '\n';
  std::ofstream writefile;
  writefile.open(fname.c_str());
  writefile<<buffer;
  cout << "writing done " << '\n';
   }
int main()
{
  /* code */
  options();

  return 0;
}

Why are you declaring write()`int write();` inside `reader()` function. — Nevus, Apr 18 '19 at 05:44
@ashwinvinod this kind of stuff is covered in any [decent C++ book](https://stackoverflow.com/questions/388242/the-definitive-c-book-guide-and-list). Do yourself a favor and pick one up. — Remy Lebeau, Apr 18 '19 at 06:01

Remy Lebeau · Answer 1 · 2019-04-18T05:59:18.707

options() is not calling reader(), and reader() is not calling write(). In both cases, you are simply declaring functions, not actually calling them.

int reader(){
    ...
    int write(); // <-- a declaration, not a call!
}

int options(){
    ...
    int reader(); // <-- a declaration, not a call!
    ... 
}

int main() {
    ...
    options(); // <-- a call, not a declaration!
    ..
}

Try this instead:

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

/* data */
char buffer;
std::string fname;

int reader(){
    cout << "opening file " << fname << '\n';
    std::ifstream readfile(fname.c_str());
    readfile >> buffer;
    std::cout << buffer << '\n';
}

int write(){
    cout << "writing to file " << '\n';
    std::ofstream writefile(fname.c_str());
    writefile << buffer;
    cout << "writing done" << '\n';
}

int options(){
    cout << "************************"<< '\n';
    cout << "* Starting File editor *"<< '\n';
    cout << "************************"<< '\n';
    cout << "* Enter Filename *"<< '\n';
    cin >> fname;
    reader();
    write();
}

int main() {
    /* code */
    options();
    return 0;
}

@ashwinvinod see the example I posted. Compare it your original code. Do you see the differences? — Remy Lebeau, Apr 18 '19 at 05:55

Nevus · Answer 2 · 2019-04-18T05:52:17.963

0

You can declare functions(not compulsory in your case) after all #include statements like:

int reader();
int write();
int options();

You call write function as write(); reader function as reader(); Since functions are not returning anything you could change int reader() to void reader(), int write() to void write() and so on. Keep main as int main() though.

edited Apr 18 '19 at 05:52

answered Apr 18 '19 at 05:49

Nevus

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score 0 · Accepted Answer · answered Apr 18 '19 at 06:10

In addition to the comments above about calling the functions, it seems like it would be good to initialize buffer as a char array as shown below:

#include <iostream>
#include <fstream>
//#include <bits/stdc++.h>
#include <string>
#include <iomanip>
#include <unistd.h>
#include <sstream>
using namespace std;/* std */

/* data */
char buffer[]{"Short test"};
std::string fname;
void write(){
  cout << "writing to file  " << '\n';
  std::ofstream writefile;
  writefile.open(fname.c_str());
  writefile<<buffer;
  cout << "writing done " << '\n';
}
void reader(){
  std::ifstream readfile;
  readfile.open(fname.c_str());
  readfile>>buffer;
  std::cout << buffer<< '\n';
  write();
}
void options(){
  cout << "************************"<< '\n';
  cout << "* Starting File editor *"<< '\n';
  cout << "************************"<< '\n';
  cout << "*    Enter Filename    *"<< '\n';
  cin >>fname;
  cout << "Opening File"<<fname<< '\n';
   reader();
  std::cout << buffer<< '\n';
}

int main()
{
  /* code */
  options();

  return 0;
}

C++ function unable to another function and ends automaticly

3 Answers3