NAME
fsync —
synchronise changes to a
file
LIBRARY
library “libc”
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
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
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
HISTORY
The fsync() function call appeared in
4.2BSD.