Here are the pros and cons of the DBM file-locking wrappers available from CPAN:
On some operating systems (FreeBSD, for example), it is possible to
lock on tie:
tie my %t, 'DB_File', $DBM_FILE, O_RDWR | O_EXLOCK, 0664;
and release the lock only by untying the file. Check if the
O_EXLOCK flag is available on your operating
system before you try to use this method!
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