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authorIngo Schwarze <schwarze@cvs.openbsd.org>2014-11-30 19:56:13 +0000
committerIngo Schwarze <schwarze@cvs.openbsd.org>2014-11-30 19:56:13 +0000
commita4f0e258efa26b7cf54bcc3a215dc196b60430be (patch)
tree02b6bd3f6c4a72bf5e50d91445b57330d144fcb6 /lib/libc/sys/flock.2
parentdaccb064d8053d3d3a9b14e268069a2516969d06 (diff)
move the description of flags from the SYNOPSIS to the DESCRIPTION;
from <kaspars at bankovskis dot net>, minimally tweaked by me; ok guenther@ jmc@
Diffstat (limited to 'lib/libc/sys/flock.2')
-rw-r--r--lib/libc/sys/flock.244
1 files changed, 25 insertions, 19 deletions
diff --git a/lib/libc/sys/flock.2 b/lib/libc/sys/flock.2
index 4b486d80260..497444df477 100644
--- a/lib/libc/sys/flock.2
+++ b/lib/libc/sys/flock.2
@@ -1,4 +1,4 @@
-.\" $OpenBSD: flock.2,v 1.18 2013/08/14 06:32:28 jmc Exp $
+.\" $OpenBSD: flock.2,v 1.19 2014/11/30 19:56:12 schwarze Exp $
.\" $NetBSD: flock.2,v 1.5 1995/02/27 12:32:32 cgd Exp $
.\"
.\" Copyright (c) 1983, 1991, 1993
@@ -30,19 +30,14 @@
.\"
.\" @(#)flock.2 8.2 (Berkeley) 12/11/93
.\"
-.Dd $Mdocdate: August 14 2013 $
+.Dd $Mdocdate: November 30 2014 $
.Dt FLOCK 2
.Os
.Sh NAME
.Nm flock
.Nd apply or remove an advisory lock on an open file
.Sh SYNOPSIS
-.Fd #include <fcntl.h>
-.Pp
-.Fd #define LOCK_SH 1 /* shared lock */
-.Fd #define LOCK_EX 2 /* exclusive lock */
-.Fd #define LOCK_NB 4 /* don't block when locking */
-.Fd #define LOCK_UN 8 /* unlock */
+.In fcntl.h
.Ft int
.Fn flock "int fd" "int operation"
.Sh DESCRIPTION
@@ -51,18 +46,25 @@ applies or removes an
.Em advisory
lock on the file associated with the file descriptor
.Fa fd .
-A lock is applied by specifying an
+The
.Fa operation
-parameter that is one of
+argument is one of:
+.Pp
+.Bl -tag -width LOCK_SH -offset indent -compact
+.It Dv LOCK_SH
+Apply a shared lock.
+.It Dv LOCK_EX
+Apply an exclusive lock.
+.It Dv LOCK_UN
+Remove an existing lock.
+.El
+.Pp
.Dv LOCK_SH
-or
+and
.Dv LOCK_EX
-with the optional addition of
-.Dv LOCK_NB .
-To unlock an existing lock,
-.Fa operation
-should be
-.Dv LOCK_UN .
+may be combined with the optional
+.Dv LOCK_NB
+for nonblocking mode.
.Pp
Advisory locks allow cooperating processes to perform
consistent operations on files, but do not guarantee
@@ -89,9 +91,13 @@ after other processes have gained and released the lock).
Requesting a lock on an object that is already locked normally causes
the caller to be blocked until the lock may be acquired.
If
+.Fa operation
+is the bitwise OR of
.Dv LOCK_NB
-is included in
-.Fa operation ,
+and
+.Dv LOCK_SH
+or
+.Dv LOCK_EX ,
then this will not happen; instead the call will fail and the error
.Er EWOULDBLOCK
will be returned.