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SYNC(2)			      System Calls Manual		       SYNC(2)

NAME
       sync -- schedule	file system updates

LIBRARY
       Standard	C Library (libc, -lc)

SYNOPSIS
       #include	<unistd.h>

       void
       sync(void);

DESCRIPTION
       The  sync()  system  call forces	a write	of dirty (modified) buffers in
       the block buffer	cache out to disk.  The	kernel keeps this  information
       in core to reduce the number of disk I/O	transfers required by the sys-
       tem.   As  information  in  the	cache  is lost after a system crash, a
       sync() system call is issued frequently by the kernel process syncer(4)
       (about every 30 seconds).

       The fsync(2) system call	may be used to synchronize individual file de-
       scriptor	attributes.

SEE ALSO
       fsync(2), syncer(4), sync(8)

HISTORY
       The sync() function appeared in Version 3 AT&T UNIX.

BUGS
       The sync() system call may return before	 the  buffers  are  completely
       flushed.

FreeBSD	13.2		       December	1, 2017			       SYNC(2)
NAME | LIBRARY | SYNOPSIS | DESCRIPTION | SEE ALSO | HISTORY | BUGS

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