FSYNC(2) MachTen Programmer’s Manual FSYNC(2)

NAME
fsync - synchronize a file’s in-core state with that on disk

SYNOPSIS
#include <unistd.h>

int
fsync(int fd)

DESCRIPTION
Fsync() causes all modified data and attributes of fd to be moved to a
permanent storage device. This normally results in all in-core modified
copies of buffers for the associated file to be written to a disk.

Fsync() should be used by programs that require a file to be in a known
state, for example, in building a simple transaction facility.

RETURN VALUES
A 0 value is returned on success. A -1 value indicates an error.

ERRORS
The fsync() fails if:

[EBADF] Fd is not a valid descriptor.

[EINVAL] Fd refers to a socket, not to a file.

[EIO] An I/O error occurred while reading from or writing to the
file system.

SEE ALSO
sync(2), sync(8), update(8)

HISTORY
The fsync function call appeared in 4.2BSD.

4.2 Berkeley Distribution June 4, 1993 1