fsync(2) - NetBSD Manual Pages

FSYNC(2)                  NetBSD 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.

NetBSD 1.4                       June 4, 1993                                1