Then you're in luck. You want an exclusive lock on the file:

use Fcntl ':flock'; # import LOCK_* constants

my $filename = "somefile.txt";
open FILE, ">>$filename" or die "Cannot open $filename for writing: $!
+";
flock FILE, LOCK_EX      or die "Cannot get exclusive lock on $filenam
+e: $!";
[download]

Just be sure not to forget to unlock the file when done. Plus, my code above is for appending, which is what I suspect you want.

Cheers,
Ovid

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