basic_istream::ignore

To extract and discard a number of characters.

  basic_istream<charT, traits>& ignore
  (steamsize n = 1, int_type delim = traits::eof());

Remarks

The function ignore() will extract and discard characters until:

a limit is met (the first argument)
end-of-file is encountered (in which case setstate(eofbit) is called)

The next character c is equal to the delimiter delim, in which case it is extracted except when c is equal to traits::eof();

The this pointer is returned.

Listing: Example of basic_istream::ignore() usage:

// The file ewl-test contains:
// char ch;  // to save char

//          /*This C comment will remain */ 

// while((ch = in.get())!= EOF) cout.put(ch); 

// // read until failure

// /* the C++ comments won't */ 

#include <iostream>

#include <fstream> 

#include <cstdlib>             

char inFile[] = "ewl-test";

char bslash = '/';

int main()

{

using namespace std;

   ifstream in(inFile);

   if(!in.is_open())

      {cout << "file not opened"; exit(1);}

   char ch;

   while((ch = in.get()) != EOF)

   {

      if(ch == bslash && in.peek() == bslash)

      {

         in.ignore(100, '\n');

         cout << '\n';

      }

      else       cout << ch;

   }

   return 0;

}

Result:

  char ch;
       /*This C comment will remain */ 
  while((ch = in.get())!= EOF) cout.put(ch); 
  /* the C++ comments won't */