openbsd-ports/infrastructure/build/dolock

38 lines
1.1 KiB
Perl
Executable File

#! /usr/bin/perl
# $OpenBSD: dolock,v 1.1 2004/11/07 10:09:35 espie Exp $
# Copyright (c) 2004 Marc Espie <espie@openbsd.org>
#
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
use strict;
use warnings;
use Fcntl;
if (@ARGV != 1) {
exit(1);
}
my $fname = shift;
my $done = 0;
while(1) {
if (sysopen my $handle, $fname, O_WRONLY | O_EXCL | O_CREAT, 0666) {
close($handle);
exit(0);
}
unless ($done) {
print STDERR "Awaiting lock $fname\n";
$done = 1;
}
sleep(1);
}