5.1.4. struct uio Structure

This structure is used for moving data between the kernel and user spaces through read() and write() system calls. It is defined in /usr/src/sys/sys/uio.h:

struct uio {
        struct  iovec *uio_iov;
        int     uio_iovcnt;
        off_t   uio_offset;
        int     uio_resid;
        enum    uio_seg uio_segflg;
        enum    uio_rw uio_rw;
        struct  proc *uio_procp;
};