multiple instance on Unix

[Cameron Laird]

In article <x7d604xxv3.fsf at guru.mired.org>, Mike Meyer  <mwm at mired.org> wrote:
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>The (old) standard method for locking on Unix is to use a file. Open
>it in exclusive mode. Using os.open(<filename>, O_EXCL | O_RDONLY) (or
>O_WRONLY, or O_RDWR) should do the trick.
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*My* favorite is to open a server socket; its semantics are
exactly those one wants, without having to tend to filesystem
hygiene with its attendant race and security challenges.