NetBSD/lib/libc/sys/fdatasync.2

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.\" $NetBSD: fdatasync.2,v 1.1 1998/06/05 20:48:59 kleink Exp $
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.\" Copyright (c) 1998 The NetBSD Foundation, Inc.
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.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Klaus Klein.
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.Dd May 30, 1998
.Dt FDATASYNC 2
.Os NetBSD 1.4
.Sh NAME
.Nm fdatasync
.Nd synchronise the data of a file
.Sh SYNOPSIS
.Fd #include <unistd.h>
.Ft int
.Fn fdatasync "int filedes"
.Sh DESCRIPTION
The
.Fn fdatasync
function forces all currently queued I/O operations associated with
the file indicated by the file descriptor
.Fa filedes
to the synchronised I/O completition state.
.Pp
The functionality is as described for
.Xr fsync 2 ,
with the exception that all I/O operations are completed as defined
for synchronised I/O data integrity completion.
.Pp
.Sh RETURN VALUES
If successful, the
.Fn fdatasync
function returns the value 0. Otherwise, the function returns the
value -1 and sets
.Dv errno
to indicate the error. If the
.Fn fdatasync
function fails, outstanding I/O operations are not
guaranteed to have been completed.
.Sh ERRORS
The
.Fn fdatasync
function will fail if:
.Bl -tag -width Er
.It Bq Er EBADF
The
.Fa filedes
argument is not a valid file descriptor.
.It Bq Er EINVAL
This implementation does not support syncronised I/O for this file.
.It Bq Er ENOSYS
The function
.Fn fdatasync
is not supported by this implementation.
.El
.Pp
In the event that any of the queued I/O operations fail,
.Fn fdatasync
returns the eror conditions defined for
.Xr read 2
and
.Xr write 2 .
.Sh SEE ALSO
.Xr fsync 2 ,
.Xr open 2 ,
.Xr read 2 ,
.Xr write 2
.Sh STANDARDS
The
.Fn fdatasync
function conforms to
.St -p1003.1b-93 .