nbtest.c

来自「LINUX设备驱动2源代码」· C语言 代码 · 共 36 行

/*
 * nbtest.c: read and write in non-blocking mode
 *
 * Tested with 1.2 on the x86
 *
 * Actually, it should run with any Unix
 */

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <errno.h>

char buffer[4096];

int main(int argc, char **argv)
{
    int delay=1, n, m=0;

    if (argc>1) delay=atoi(argv[1]);
    fcntl(0, F_SETFL, fcntl(0,F_GETFL) | O_NONBLOCK); /* stdin */
    fcntl(1, F_SETFL, fcntl(1,F_GETFL) | O_NONBLOCK); /* stdout */

    while (1) {
        n=read(0, buffer, 4096);
        if (n>=0)
            m=write(1, buffer, n);
        if ((n<0 || m<0) && (errno != EAGAIN))
            break;
        sleep(delay);
    }
    perror( n<0 ? "stdin" : "stdout");
    exit(1);
}