This was an example of the implementation of select() in Beej's code;

Code:
/*
** select.c -- a select() demo
*/

#include <stdio.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>

#define STDIN 0  // file descriptor for standard input

int main(void)
{
    struct timeval tv;
    fd_set readfds;

    tv.tv_sec = 2;
    tv.tv_usec = 500000;

    FD_ZERO(&readfds);
    FD_SET(STDIN, &readfds);

    // don't care about writefds and exceptfds:
    select(STDIN+1, &readfds, NULL, NULL, &tv);

    if (FD_ISSET(STDIN, &readfds))
        printf("A key was pressed!\n");
    else
        printf("Timed out.\n");

    return 0;
}
I don't like to copy code, so i tried to write my own code from looking at that, but it didn't work, so i tried copying the code, and that didn't work either, my compiler doesn't recognize any of the "FD" commands. this is all the code, and it was linked to w2_32.lib.

Edit: because it seems that those FD commands are all over his code, i got discouraged and gave up on his tutorial.