DragonFly On-Line Manual Pages
FSYNC(2) DragonFly System Calls Manual FSYNC(2)
fsync -- synchronise changes to a file
Standard C Library (libc, -lc)
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.
The fsync() function returns the value 0 if successful; otherwise the
value -1 is returned and the global variable errno is set to indicate the
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.
sync(2), syncer(4), sync(8)
The fsync() function call appeared in 4.2BSD.
DragonFly 4.7 June 4, 1993 DragonFly 4.7