.\" Copyright (c) 1980 Regents of the University of California.
.\" All rights reserved. The Berkeley software License Agreement
.\" specifies the terms and conditions for redistribution.
.\" @(#)vwrite.2v 4.1 (Berkeley) %G%
vwrite \- write (virtually) to file
.B vwrite(filedes, buffer, nbytes)
This call is likely to be replaced by more general virtual memory facilities
system call is used in conjunction with
to perform efficient updating of large files.
and updating of the data in the buffer which was given to
of the same buffer to the same
at the same offset in the file
will cause data which has been modified since it was
to) the file to be returned to the file.
Returns \-1 on error: bad descriptor, buffer address, count or alignment
as well as on physical I/O errors.
is defined only when no other
since the one matching the
This call is peculiar to this version of UNIX.
It will be superseded by more general
virtual memory facilities in future versions of the system.