freebsd-dev/lib/libc/sys/sync.2
Ruslan Ermilov 2faeeff4c9 mdoc(7) police: Tidy up the syscall language.
Stop calling system calls "function calls".

Use "The .Fn system call" a-la "The .Nm utility".

When referring to a non-BSD implementation in
the HISTORY section, call syscall a function,
to be safe.
2002-12-18 09:22:32 +00:00

82 lines
2.7 KiB
Groff

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.\" @(#)sync.2 8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
.Dd June 4, 1993
.Dt SYNC 2
.Os
.Sh NAME
.Nm sync
.Nd "schedule file system updates"
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In unistd.h
.Ft void
.Fn sync void
.Sh DESCRIPTION
The
.Fn 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 system.
As information in the cache is lost after a system crash, a
.Fn sync
system call is issued
frequently
by the user process
.Xr syncer 4
(about every 30 seconds).
.Pp
The
.Xr fsync 2
system call
may be used to synchronize individual file descriptor
attributes.
.Sh SEE ALSO
.Xr fsync 2 ,
.Xr syncer 4 ,
.Xr sync 8
.Sh BUGS
The
.Fn sync
system call
may return before the buffers are completely flushed.
.Sh HISTORY
The
.Fn sync
function appeared in
.At v6 .