uio(9s)uio(9s)NAMEuio - General: Describes I/O, either single vector or multiple vectors
SYNOPSIS
─────────────────────────────
Member Name Data Type
─────────────────────────────
uio_iov struct iovec *
uio_iovcnt int
uio_offset off_t
uio_segflg enum uio_seg
uio_resid int
uio_rw enum uio_rw
─────────────────────────────
MEMBERS
Specifies a pointer to the first iovec structure. The iovec structure
has two members: one that specifies the address of the segment and
another that specifies the size of the segment. The system allocates
contiguous iovec structures for a given transfer. Specifies the number
of iovec structures for this transfer. Specifies the offset within the
file. Specifies the segment type. This member can be set to one of the
following values: UIO_USERSPACE (the segment is from the user data
space), UIO_SYSSPACE (the segment is from the system space), or
UIO_USERISPACE (the segment is from the user I space). Specifies the
number of bytes that still need to be transferred. Specifies whether
the transfer is a read or a write. This member is set by read and write
system calls according to the corresponding field in the file descrip‐
tor. This member can be set to one of the following values: UIO_READ
(read transfer), UIO_WRITE (write transfer), or UIO_AIORW (Alpha I/O
read/write transfer).
DESCRIPTION
The uio data structure describes, either singler-vector or multiple-
vector I/O. Typically, kernel modules do not manipulate the members of
this data structure. However, the data structure is presented here for
the purpose of understanding the uiomove routine, which operates on the
members of the uio structure.
FILESSEE ALSO
Routines: uiomove(9r)uio(9s)