fsync
Synopsis
#include <unistd.h>
int fsync(int fildes);
Status
Declared, not implemented
Conformance
IEEE Std 1003.1-2017
Description
The fsync() function shall request that all data for the open file descriptor named by fildes is to be transferred
to the storage device associated with the file described by fildes. The nature of the transfer is
implementation-defined.
The fsync() function shall not return until the system has completed that action or until an error is detected.
If _POSIX_SYNCHRONIZED_IO is defined, the fsync() function shall force all currently queued I/O operations
associated with the file indicated by file descriptor fildes to the synchronized I/O completion state. All I/O
operations shall be completed as defined for synchronized I/O file integrity completion.
Return value
Upon successful completion, fsync() shall return 0. Otherwise, -1 shall be returned and errno set to indicate
the error. If the fsync() function fails, outstanding I/O operations are not guaranteed to have been completed.
Errors
The fsync() function shall fail if:
EBADF- The fildes argument is not a valid descriptor.EINTR- Thefsync()function was interrupted by a signal.EINVAL- The fildes argument does not refer to a file on which this operation is possible.EIO- An I/O error occurred while reading from or writing to the file system.
In the event that any of the queued I/O operations fail, fsync() shall return the error conditions defined for
read() and write().
Tests
Untested
Known bugs
None