DragonFly On-Line Manual Pages


FSYNC(2)		 DragonFly System Calls Manual		      FSYNC(2)

NAME

fsync -- synchronise changes to a file

LIBRARY

Standard C Library (libc, -lc)

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

sync(2), syncer(4), sync(8)

HISTORY

The fsync() function call appeared in 4.2BSD. DragonFly 4.1 June 4, 1993 DragonFly 4.1