streamsize in_avail ( );

Get number of characters available to read

Returns the number of characters available to read. This value depends on whether there are read positions directly available at the get pointer:

• If the get pointer has a value and this is less than the end pointer: The function returns the number of characters directly available at the get pointer before the end pointer (returns egptr()-gptr() without calling any virtual member function).
• If the get pointer is either null or has reached the end pointer: The function returns the number of characters expected to be available after an underflow. This is obtained by calling the protected virtual member function showmanyc.

Parameters

Return Value

Example

// in_avail () example
#include <iostream>
using namespace std;

int main () {

  streamsize size;
  char ch;

  streambuf * pbuf;
  pbuf = cin.rdbuf();

  cout << "Please enter some characters: ";
  cin >> ch;

  size = pbuf->in_avail();

  cout << "The first character you entered is: " << ch << endl;
  cout << size << " additional characters in input buffer" << endl;

  return 0;
}

Basic template member declaration

streamsize in_avail ( );

See also