/* * Test out reading with poll() * This should run with any Unix * * Copyright (C) 2003 Alessandro Rubini and Jonathan Corbet * Copyright (C) 2003 O'Reilly & Associates * * The source code in this file can be freely used, adapted, * and redistributed in source or binary form, so long as an * acknowledgment appears in derived source files.  The citation * should list that the code comes from the book "Linux Device * Drivers" by Alessandro Rubini and Jonathan Corbet, published * by O'Reilly & Associates.   No warranty is attached; * we cannot take responsibility for errors or fitness for use. * * $Id: polltest.c,v 1.1 2003/02/07 18:01:38 corbet Exp $ */#include <stdio.h>#include <unistd.h>#include <stdlib.h>#include <errno.h>#include <sys/poll.h>#include <fcntl.h>char buffer[4096];int main(int argc, char **argv){    struct pollfd pfd;    int n;    fcntl(0, F_SETFL, fcntl(0,F_GETFL) | O_NONBLOCK); /* stdin */    pfd.fd = 0;  /* stdin */    pfd.events = POLLIN;    while (1) {        n=read(0, buffer, 4096);        if (n >= 0)            write(1, buffer, n);	n = poll(&pfd, 1, -1);	if (n < 0)	    break;    }    perror( n<0 ? "stdin" : "stdout");    exit(1);}