NAME

write − write data to a device

SYNOPSIS

#include <sys/types.h>
#include <sys/errno.h>
#include <sys/open.h>
#include <sys/cred.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
int prefixwrite(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

Used for character or raw data I/O, the driver write() routine is called indirectly through cb_ops(9S) by the write(2) system call.  The write() routine supervises the data transfer from user space to a device described by the uio(9S) structure. 

The write routine should check the validity of the minor number component of dev and the user credentials pointed to by cred_p (if pertinent). 

RETURN VALUES

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

SEE ALSO

read(2), read(9E), cb_ops(9S), uio(9S)

Writing Device Drivers

SunOS 5.5/x86  —  Last change: 11 Apr 1991