| UIOMOVE(9) | Kernel Developer's Manual | UIOMOVE(9) | 
uiomove —
#include <sys/systm.h>
int
  
  uiomove(void
    *buf, size_t n,
    struct uio *uio);
uiomove() function copies up to
  n bytes between the kernel-space address pointed to by
  buf and the addresses described by
  uio, which may be in user-space or kernel-space.
The uio argument is a pointer to a
    struct uio as defined by
    <sys/uio.h>:
struct uio {
	struct	iovec *uio_iov;
	int	uio_iovcnt;
	off_t	uio_offset;
	size_t	uio_resid;
	enum	uio_rw uio_rw;
	struct	vmspace *uio_vmspace;
};
A struct uio typically describes data in motion. Several of the fields described below reflect that expectation.
struct iovec {
	void	*iov_base;
	size_t	 iov_len;
};
    
    The members in the struct iovec should only be initialized. These are:
The value of uio->uio_rw controls whether
    uiomove() copies data from buf
    to uio or vice versa.
The lesser of n or uio->uio_resid bytes are copied.
uiomove() changes fields of the structure
    pointed to by uio, such that
    uio->uio_resid is decremented by the amount of data
    moved, uio->uio_offset is incremented by the same
    amount, and the array of iovecs is adjusted to point that much farther into
    the region described. This allows multiple calls to
    uiomove() to easily be used to fill or drain the
    region of data.
uiomove() returns 0. If a
  bad address is encountered, EFAULT is returned.
| April 26, 2010 | NetBSD 10.0 |