Myselectexample.c

/*************************************************************************
	> File Name: Myselectexample.c
	> Author:Victor Qi 
	> Mail:Victor_QiGetFuture@163.com 
	> Created Time: Sun 24 Jan 2016 09:07:27 PM CST
 ************************************************************************/

#include "apue.h" 
#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
int  main(void)
{       
	fd_set rfds;
        
    struct timeval tv;
    int retval;

     /* Watch stdin (fd 0) to see when it has input. */
    FD_ZERO(&rfds);
    FD_SET(0, &rfds);

    /* Wait up to five seconds. */
    tv.tv_sec = 5;
    tv.tv_usec = 0;

    retval = select(1, &rfds, NULL, NULL, &tv);
    /* Don't rely on the value of tv now! */

    if (retval == -1)
        perror("select()");
    else if (retval)
       	printf("Data is available now.\n");
            /* FD_ISSET(0, &rfds) will be true. */
    else
        printf("No data within five seconds.\n");

    exit(EXIT_SUCCESS);
	
}