About the C++ timer

[L3ApX9L8]

So am trying to write a program that 'allows' the user to enter data for x-seconds, stopping the timer if this happens, and doing something else if this is not the case...

The only problem is, im pretty confused about the timer in c++
anyone could explain things up a bit, please?

[Duthomhas]

There is no timer in C or C++. The OS supplies one, though.

If you are on Windows:

#include <windows.h>

bool iskeypressed( unsigned long timeout = 0 /* milliseconds */ )
  {
  return WaitForSingleObject(
    GetStdHandle( STD_INPUT_HANDLE ),
    0
    ) == WAIT_OBJECT_0;
  }

http://www.google.com/search?btnI=1&q=msdn+WaitForSingleObject

If you are on POSIX (Unix/Linux/Mac OS X/etc)

#include <unistd.h>
#include <poll.h>

bool iskeypressed( unsigned long timeout = 0 /* milliseconds */ )
  {
  struct pollfd pls[ 1 ];
  pls[ 0 ].fd = STDIN_FILENO;
  pls[ 0 ].events = POLLIN | POLLPRI;
  return poll( pls, 1, (int)timeout ) > 0;
  }

http://linux.die.net/man/2/poll
_{If you are on some ancient system that does not supply poll(), let me know and I'll give you a version that uses select().}

Use the function to check for keypresses. If it returns true, then you know you have input to read. Otherwise your timeout has expired.

Hope this helps.