#include <signal.h>
#include <unistd.h>
#include <stdio.h>

int     flag = 0;

void    handler(int);

int
main(int argc, char *argv[])
{
    char buf[BUFSIZ];
    int timeout;

    /*
     * Set up a timeout of argv[1] seconds.
     */
    signal(SIGALRM, handler);
    timeout= atoi(argv[1]);
while (1){
    alarm(timeout);

    /*
     * Prompt for a string and remove the newline. 
     */
    printf("Enter a string (withen %d seconds): ", timeout);
    fgets(buf, sizeof(buf), stdin);
    buf[strlen(buf)-1] = '\0';

    /*
     * Turn off the alarm, they typed something.
     */
    alarm(0);
    if (!flag)
       printf("got %s\n", buf);

    /*
     * Display the string we're using.
     */
}
}

/*
 * handler - catch alarm signal and set flag.
 */
void
handler(int sig)
{
    signal(SIGALRM, handler);
    printf("Timeout Alarm\n");
    flag=1;
}