Copyright (c) 1998 The NetBSD Foundation, Inc.
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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.
p 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.
p .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: l -tag -width Er t Bq Er EBADF The .Fa filedes argument is not a valid file descriptor. t Bq Er EINVAL This implementation does not support syncronised I/O for this file. t Bq Er ENOSYS The function .Fn fdatasync is not supported by this implementation. .El
p 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 .
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