fsync()

Synchronize the file state

Synopsis:

#include <unistd.h>

int fsync( int filedes );

Arguments:

filedes

The descriptor for the file that you want to synchronize.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The fsync() function forces all queued I/O operations for the file specified by the filedes file descriptor to finish, synchronizing the file's state. The function blocks until this is finished. For more information about synchronizing, see “Filesystems and block I/O (devb-*) drivers” in the Fine-Tuning Your System chapter of the QNX Neutrino User's Guide.

Although similar to fdatasync(), fsync() also guarantees the integrity of file information such as access and modification times.

Returns:

0 for success, or -1 if an error occurs (errno is set).

Errors:

EBADF

The filedes argument isn't a valid file descriptor open for writing.

EINVAL

The implementation doesn't support synchronized I/O for the given file.

ENOSYS

The fsync() function isn't supported for the filesystem specified by filedes.

Classification:

POSIX 1003.1 FSC

See also:

aio_fsync(), close(), fcntl(), fdatasync(), open(), read(), sync(), write()

“Filesystems and block I/O (devb-*) drivers” in the Fine-Tuning Your System chapter of the QNX Neutrino User's Guide