NAME
    File::Flock - file locking with flock

SYNOPSIS
    use File::Flock;

    lock($filename);

    lock($filename, 'shared');

    lock($filename, undef, 'nonblocking');

    lock($filename, 'shared', 'nonblocking');

    unlock($filename);

    lock_rename($oldfilename, $newfilename)

    my $lock = new File::Flock '/somefile';

    $lock->unlock();

    $lock->lock_rename('/new/file');

    forget_locks();

DESCRIPTION
   Lock files using the flock() call. If the file to be locked does not
   exist, then the file is created. If the file was created then it will be
   removed when it is unlocked assuming it's still an empty file.

   Locks can be created by new'ing a File::Flock object. Such locks are
   automatically removed when the object goes out of scope. The unlock()
   method may also be used.

   lock_rename() is used to tell File::Flock when a file has been renamed
   (and thus the internal locking data that is stored based on the filename
   should be moved to a new name). unlock() the new name rather than the
   original name.

   Locks are released on process exit when the process that created the
   lock exits. Subprocesses that exit do not remove locks. Use
   forget_locks() or POSIX::_exit() to prevent unlocking on process exit.

SEE ALSO
   See File::Flock::Subprocess for a variant that uses a subproess to hold
   the locks so that the locks survive when the parent process forks. See
   File::Flock::Forking for a way to automatically choose between
   File::Flock and File::Flock::Subprocess.

LICENSE
   Copyright (C) 1996-2012 David Muir Sharnoff <[email protected]>
   Copyright (C) 2013 Google, Inc. This module may be used/copied/etc on
   the same terms as Perl itself.

PACKAGERS
   File::Flock is packaged for Fedora by Emmanuel Seyman
   <[email protected]>.