#include "apue.h"
#include <setjmp.h>
static void       sig_alrm(int);
static jmp_buf    env_alrm;
int
main(void)
{
    int     n;
    char    line[MAXLINE];
    if (signal(SIGALRM, sig_alrm) == SIG_ERR)
        err_sys("signal(SIGALRM) error");
    if (setjmp(env_alrm) != 0)
        err_quit("read timeout");
    alarm(10);
    if ((n = read(STDIN_FILENO, line, MAXLINE)) < 0)
        err_sys("read error");
    alarm(0);
    write(STDOUT_FILENO, line, n);
    exit(0);
}
static void
sig_alrm(int signo)
{
    longjmp(env_alrm, 1);
}
