OpenBSD可加载内核模块编程完全指南

OpenBSD可加载内核模块编程完全指南(8)         struct proc *p;
{
        printf("device opened, hi!n");
        return(0);
}

/*
* 以下动作在设备被关闭的时候执行,这里打印一段信息
*/

int
ourdevclose(dev, fflag, devtype, p)
        dev_t dev;
        int fflag, devtype;
        struct proc *p;
{
        printf("device closed! bye!n");
        return(0);
}

/*
* 定义我们设备执行的read动作,这里它把存储在内部结构ourdev_io里的string的当前值读出来
*/

int
ourdevread(dev, uio, ioflag)
        dev_t dev;
        struct uio *uio;
        int     ioflag;
{
        int resid = MAXMSGLEN;
        int error = 0;

        do {
                if (uio->uio_resid < resid)
                        resid = uio->uio_resid;

                error = uiomove(dio.msg, resid, uio);  

        } while (resid > 0 && error == 0);

        return(error);
}

/*
* ioctl操作的代码.这里定义了两个操作,一个负责从ourdev_io中读取当前值,一个负责设置当前值.
*/

int
ourdevioctl(dev, cmd, data, fflag, p)