read(9E)

NAME

read − read data from a device

SYNOPSIS

#include <sys/types.h>
#include <sys/errno.h>
#include <sys/open.h>
#include <sys/uio.h>
#include <sys/cred.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
int prefixread(dev_t dev, struct uio ∗uio_p
, cred_t ∗cred_p);

INTERFACE LEVEL

Architecture independent level 1 (DDI/DKI). This entry point is optional.

ARGUMENTS

dev Device number.

uio_p Pointer to the uio(9S) structure that describes where the data is to be stored in user space.

cred_p Pointer to the user credential structure for the I/O transaction.

DESCRIPTION

The driver read() routine is called indirectly through cb_ops(9S) by the read(2) system call. The read() routine should check the validity of the minor number component of dev and the user credential structure pointed to by cred_p (if pertinent). The read() routine should supervise the data transfer into the user space described by the uio(9S) structure.

RETURN VALUES

The read() routine should return 0 for success, or the appropriate error number.

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