1997-01-08 20:12:59 +00:00
|
|
|
.\"
|
1998-07-08 05:29:05 +00:00
|
|
|
.\" Copyright (C) 1998 John D. Polstra. All rights reserved.
|
1997-01-08 20:12:59 +00:00
|
|
|
.\"
|
|
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
|
|
.\" modification, are permitted provided that the following conditions
|
|
|
|
.\" are met:
|
|
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
|
|
.\"
|
|
|
|
.\" THIS SOFTWARE IS PROVIDED BY JOHN D. POLSTRA AND CONTRIBUTORS ``AS IS'' AND
|
|
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL JOHN D. POLSTRA OR CONTRIBUTORS BE LIABLE
|
|
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
|
|
.\" SUCH DAMAGE.
|
|
|
|
.\"
|
1999-08-28 01:08:13 +00:00
|
|
|
.\" $FreeBSD$
|
1997-01-08 20:12:59 +00:00
|
|
|
.\"
|
1998-07-08 05:29:05 +00:00
|
|
|
.Dd July 7, 1998
|
2001-07-10 14:16:33 +00:00
|
|
|
.Os
|
1997-01-08 20:12:59 +00:00
|
|
|
.Dt LOCKF 1
|
|
|
|
.Sh NAME
|
|
|
|
.Nm lockf
|
|
|
|
.Nd execute a command while holding a file lock
|
|
|
|
.Sh SYNOPSIS
|
|
|
|
.Nm
|
1998-07-08 05:29:05 +00:00
|
|
|
.Op Fl ks
|
1997-01-08 20:12:59 +00:00
|
|
|
.Op Fl t Ar seconds
|
|
|
|
.Ar file
|
|
|
|
.Ar command
|
|
|
|
.Op Ar arguments
|
|
|
|
.Sh DESCRIPTION
|
|
|
|
The
|
|
|
|
.Nm
|
|
|
|
utility acquires an exclusive lock on a
|
|
|
|
.Ar file ,
|
|
|
|
creating it if necessary.
|
|
|
|
While holding the lock, it executes a
|
|
|
|
.Ar command
|
|
|
|
with optional
|
|
|
|
.Ar arguments .
|
|
|
|
After the
|
|
|
|
.Ar command
|
|
|
|
completes,
|
|
|
|
.Nm
|
1998-07-08 05:29:05 +00:00
|
|
|
releases the lock, and removes the
|
|
|
|
.Ar file
|
|
|
|
unless the
|
|
|
|
.Fl k
|
2001-08-14 10:01:54 +00:00
|
|
|
option is specified.
|
|
|
|
.Bx Ns -style
|
|
|
|
locking is used, as described in
|
1997-01-08 20:12:59 +00:00
|
|
|
.Xr flock 2 ;
|
2001-07-15 08:06:20 +00:00
|
|
|
the mere existence of the
|
1997-01-08 20:12:59 +00:00
|
|
|
.Ar file
|
|
|
|
is not considered to constitute a lock.
|
|
|
|
.Pp
|
|
|
|
The following options are supported:
|
|
|
|
.Bl -tag -width Fl
|
1998-07-08 05:29:05 +00:00
|
|
|
.It Fl k
|
|
|
|
Causes the lock file to be kept (not removed) after the command
|
|
|
|
completes.
|
1997-01-08 20:12:59 +00:00
|
|
|
.It Fl s
|
|
|
|
Causes
|
|
|
|
.Nm
|
|
|
|
to operate silently.
|
|
|
|
Failure to acquire the lock is indicated only in the exit status.
|
|
|
|
.It Fl t Ar seconds
|
2004-07-02 22:22:35 +00:00
|
|
|
Specifies a timeout for waiting for the lock.
|
|
|
|
By default,
|
1997-01-08 20:12:59 +00:00
|
|
|
.Nm
|
|
|
|
waits indefinitely to acquire the lock.
|
|
|
|
If a timeout is specified with this option,
|
|
|
|
.Nm
|
|
|
|
will wait at most the given number of
|
|
|
|
.Ar seconds
|
2004-07-02 22:22:35 +00:00
|
|
|
before giving up.
|
|
|
|
A timeout of 0 may be given, in which case
|
1997-01-08 20:12:59 +00:00
|
|
|
.Nm
|
|
|
|
will fail unless it can acquire the lock immediately.
|
|
|
|
.El
|
|
|
|
.Pp
|
|
|
|
In no event will
|
|
|
|
.Nm
|
|
|
|
break a lock that is held by another process.
|
2005-01-17 07:44:44 +00:00
|
|
|
.Sh EXIT STATUS
|
1997-01-08 20:12:59 +00:00
|
|
|
If
|
|
|
|
.Nm
|
1997-01-09 19:53:21 +00:00
|
|
|
successfully acquires the lock, it returns the exit status produced by
|
1997-01-08 20:12:59 +00:00
|
|
|
.Ar command .
|
1997-01-09 19:53:21 +00:00
|
|
|
Otherwise, it returns one of the exit codes defined in
|
|
|
|
.Xr sysexits 3 ,
|
|
|
|
as follows:
|
|
|
|
.Bl -tag -width F_CANTCREATX
|
|
|
|
.It Dv EX_TEMPFAIL
|
|
|
|
The specified lock file was already locked by another process.
|
|
|
|
.It Dv EX_CANTCREAT
|
2002-04-20 12:18:28 +00:00
|
|
|
The
|
1997-01-09 19:53:21 +00:00
|
|
|
.Nm
|
2002-04-20 12:18:28 +00:00
|
|
|
utility
|
1997-01-09 19:53:21 +00:00
|
|
|
was unable to create the lock file, e.g., because of insufficient access
|
|
|
|
privileges.
|
|
|
|
.It Dv EX_USAGE
|
|
|
|
There was an error on the
|
|
|
|
.Nm
|
|
|
|
command line.
|
|
|
|
.It Dv EX_OSERR
|
|
|
|
A system call (e.g., fork) failed unexpectedly.
|
|
|
|
.El
|
1997-01-08 20:12:59 +00:00
|
|
|
.Sh SEE ALSO
|
1997-01-09 19:53:21 +00:00
|
|
|
.Xr flock 2 ,
|
1998-03-23 07:48:45 +00:00
|
|
|
.Xr sysexits 3
|
2000-12-10 01:10:54 +00:00
|
|
|
.Sh HISTORY
|
2002-04-20 12:18:28 +00:00
|
|
|
A
|
2000-12-10 01:10:54 +00:00
|
|
|
.Nm
|
2002-04-20 12:18:28 +00:00
|
|
|
utility first appeared in
|
2000-12-10 01:10:54 +00:00
|
|
|
.Fx 2.2 .
|
1997-01-08 20:12:59 +00:00
|
|
|
.Sh AUTHORS
|
1998-03-23 07:48:45 +00:00
|
|
|
.An John Polstra Aq jdp@polstra.com .
|