fdatasync(2)fdatasync(2)NAMEfdatasync - Writes data changes in a file to permanent storage
SYNOPSIS
#include <unistd.h>
int fdatasync (
int fildes );
PARAMETERS
Specifies a valid open file descriptor.
DESCRIPTION
The fdatasync function causes system buffers containing a file's modi‐
fied data to be written to permanent storage. The fdatasync function
does not return until the operation has been completed. The fdatasync
function provides data integrity, ensuring that data in permanent stor‐
age is identical to data in the buffer. However, use of fdatasync does
not guarantee that file control information such as owner and modifica‐
tion time has been updated to permanent storage (see the fsync func‐
tion).
NOTES
The file identified by the fildes parameter must be open for writing
when the fdatasync function is issued or the call will fail.
RETURN VALUES
Upon successful completion, the fdatasync function returns a value of 0
(zero). If the fdatasync function fails, a value of -1 is returned and
errno is set to indicate the error. If fdatasync fails, outstanding I/O
operations are not guaranteed to have been completed.
ERRORS
If the fdatasync function fails, errno may be set to one of the follow‐
ing values: The fildes parameter is not a valid file descriptor. The
fildes parameter does not refer to a file on which this operation is
possible.
If any queued I/O operations fail, the fdatasync function returns error
conditions defined for the read and write functions.
SEE ALSO
Functions: fcntl(2), fsync(2), open(2), read(2), sync(2), write(2)fdatasync(2)
