'\" te
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.TH fdatasync 3C "5 Feb 2008" "SunOS 5.11" "Standard C Library Functions"
.SH NAME
fdatasync \- synchronize a file's data
.SH SYNOPSIS
.LP
.nf
#include <unistd.h>

\fBint\fR \fBfdatasync\fR(\fBint\fR \fIfildes\fR);
.fi

.SH DESCRIPTION
.sp
.LP
The \fBfdatasync()\fR function forces all currently queued I/O operations associated with the file indicated by file descriptor \fIfildes\fR to the synchronized I/O completion state.
.sp
.LP
The functionality is as described for \fBfsync\fR(3C) (with the symbol \fB_XOPEN_REALTIME\fR defined), with the exception that all I/O operations are completed as defined for synchronised I/O data integrity completion.
.SH RETURN VALUES
.sp
.LP
If successful, the \fBfdatasync()\fR function returns \fB0\fR. Otherwise, the function returns \fB\(mi1\fR and sets \fBerrno\fR to indicate the error. If the \fBfdatasync()\fR function fails, outstanding I/O operations are not guaranteed to have been completed.
.SH ERRORS
.sp
.LP
The  \fBfdatasync()\fR function will fail if:
.sp
.ne 2
.mk
.na
\fB\fBEBADF\fR\fR
.ad
.RS 10n
.rt  
The \fIfildes\fR argument is not a valid file descriptor open for writing.
.RE

.sp
.ne 2
.mk
.na
\fB\fBEINVAL\fR\fR
.ad
.RS 10n
.rt  
The system does not support synchronized I/O for this file.
.RE

.sp
.ne 2
.mk
.na
\fB\fBENOSYS\fR\fR
.ad
.RS 10n
.rt  
The function \fBfdatasync()\fR is not supported by the system.
.RE

.sp
.LP
In the event that any of the queued I/O operations fail, \fBfdatasync()\fR returns the error conditions defined for \fBread\fR(2) and \fBwrite\fR(2). 
.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp

.sp
.TS
tab() box;
cw(2.75i) |cw(2.75i) 
lw(2.75i) |lw(2.75i) 
.
ATTRIBUTE TYPEATTRIBUTE VALUE
_
Interface StabilityCommitted
_
MT-LevelAsync-Signal-Safe
_
StandardSee \fBstandards\fR(5).
.TE

.SH SEE ALSO
.sp
.LP
\fBfcntl\fR(2), \fBopen\fR(2), \fBread\fR(2), \fBwrite\fR(2), \fBfsync\fR(3C), \fBaio_fsync\fR(3C), \fBfcntl.h\fR(3HEAD), \fBattributes\fR(5), \fBstandards\fR(5)