Hello,
I am having trouble understanding flock
I found this code on here and wonder if I am on the right track in the way this is working.
It looks like a second program (meaning a different program altoghter) could open and write to the real file since the real file being written to is
not really locked 
use strict;
use Fcntl qw(:flock);

my $file = 'data.file';
my $SEMAPHORE = "$file.lck";

open(S, ">$SEMAPHORE) || die "Foo ($!)";
flock(S, LOCK_EX);
open(FH, ">$file") || die "Foofoo ($!)";
# Muck with file
close FH;
close S;

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In reply to Trying to understand flock by toniax

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